P-loop containing Nucleoside Triphosphate Hydrolases; Members of the P-loop NTPase domain superfamily are characterized by a conserved nucleotide phosphate-binding motif, also referred to as the Walker A motif (GxxxxGK[S/T], where x is any residue), and the Walker B motif (hhhh[D/E], where h is a hydrophobic residue). The Walker A and B motifs bind the beta-gamma phosphate moiety of the bound nucleotide (typically ATP or GTP) and the Mg2+ cation, respectively. The P-loop NTPases are involved in diverse cellular functions, and they can be divided into two major structural classes: the KG (kinase-GTPase) class which includes Ras-like GTPases and its circularly permutated YlqF-like; and the ASCE (additional strand catalytic E) class which includes ATPase Binding Cassette (ABC), DExD/H-like helicases, 4Fe-4S iron sulfur cluster binding proteins of NifH family, RecA-like F1-ATPases, and ATPases Associated with a wide variety of Activities (AAA). Also included are a diverse set of nucleotide/nucleoside kinase families.

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 433660831   5 DARMLASQNIVIILCGNKKDLDADREVTFLEASRFAQENELMFLETSALTGENVEEAFVQCARKI 69
Cdd:cd04113   97 DARTLASPDIVIILVGNKKDLEDDREVTFLEASRFAQENGLLFLETSALTGENVEEAFLKCARSI 161

Rab GTPase family 4 (Rab4); Rab4 subfamily. Rab4 has been implicated in numerous functions within the cell. It helps regulate endocytosis through the sorting, recycling, and degradation of early endosomes. Mammalian Rab4 is involved in the regulation of many surface proteins including G-protein-coupled receptors, transferrin receptor, integrins, and surfactant protein A. Experimental data implicate Rab4 in regulation of the recycling of internalized receptors back to the plasma membrane. It is also believed to influence receptor-mediated antigen processing in B-lymphocytes, in calcium-dependent exocytosis in platelets, in alpha-amylase secretion in pancreatic cells, and in insulin-induced translocation of Glut4 from internal vesicles to the cell surface. Rab4 is known to share effector proteins with Rab5 and Rab11. GTPase activating proteins (GAPs) interact with GTP-bound Rab and accelerate the hydrolysis of GTP to GDP. Guanine nucleotide exchange factors (GEFs) interact with GDP-bound Rabs to promote the formation of the GTP-bound state. Rabs are further regulated by guanine nucleotide dissociation inhibitors (GDIs), which facilitate Rab recycling by masking C-terminal lipid binding and promoting cytosolic localization. Most Rab GTPases contain a lipid modification site at the C-terminus, with sequence motifs CC, CXC, or CCX. Lipid binding is essential for membrane attachment, a key feature of most Rab proteins. Due to the presence of truncated sequences in this CD, the lipid modification site is not available for annotation.

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 433660831   5 DARMLASQNIVIILCGNKKDLDADREVTFLEASRFAQENELMFLETSALTGENVEEAFVQCARKI 69
Cdd:cd04113   97 DARTLASPDIVIILVGNKKDLEDDREVTFLEASRFAQENGLLFLETSALTGENVEEAFLKCARSI 161

Ras family; Includes sub-families Ras, Rab, Rac, Ral, Ran, Rap Ypt1 and more. Shares P-loop motif with GTP_EFTU, arf and myosin_head. See pfam00009 pfam00025, pfam00063. As regards Rab GTPases, these are important regulators of vesicle formation, motility and fusion. They share a fold in common with all Ras GTPases: this is a six-stranded beta-sheet surrounded by five alpha-helices.

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 433660831    4 PDARMLASQNIVIILCGNKKDLDADREVTFLEASRFAQENELMFLETSALTGENVEEAFVQCARKILN 71
Cdd:pfam00071  95 EEILRHADENVPIVLVGNKCDLEDQRVVSTEEGEALAKELGLPFMETSAKTNENVEEAFEELAREILK 162

small GTP-binding protein domain; Proteins with a small GTP-binding domain recognized by this model include Ras, RhoA, Rab11, translation elongation factor G, translation initiation factor IF-2, tetratcycline resistance protein TetM, CDC42, Era, ADP-ribosylation factors, tdhF, and many others. In some proteins the domain occurs more than once.This model recognizes a large number of small GTP-binding proteins and related domains in larger proteins. Note that the alpha chains of heterotrimeric G proteins are larger proteins in which the NKXD motif is separated from the GxxxxGK[ST] motif (P-loop) by a long insert and are not easily detected by this model. [Unknown function, General]

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....
gi 433660831    9 LASQNIVIILCGNKKDLDADREVTFlEASRFAQENELMFLETSALTGENVEEAF 62
Cdd:TIGR00231 105 HADSGVPIILVGNKIDLKDADLKTH-VASEFAKLNGEPIIPLSAETGKNIDSAF 157

Rab GTPase family 4 (Rab4); Rab4 subfamily. Rab4 has been implicated in numerous functions within the cell. It helps regulate endocytosis through the sorting, recycling, and degradation of early endosomes. Mammalian Rab4 is involved in the regulation of many surface proteins including G-protein-coupled receptors, transferrin receptor, integrins, and surfactant protein A. Experimental data implicate Rab4 in regulation of the recycling of internalized receptors back to the plasma membrane. It is also believed to influence receptor-mediated antigen processing in B-lymphocytes, in calcium-dependent exocytosis in platelets, in alpha-amylase secretion in pancreatic cells, and in insulin-induced translocation of Glut4 from internal vesicles to the cell surface. Rab4 is known to share effector proteins with Rab5 and Rab11. GTPase activating proteins (GAPs) interact with GTP-bound Rab and accelerate the hydrolysis of GTP to GDP. Guanine nucleotide exchange factors (GEFs) interact with GDP-bound Rabs to promote the formation of the GTP-bound state. Rabs are further regulated by guanine nucleotide dissociation inhibitors (GDIs), which facilitate Rab recycling by masking C-terminal lipid binding and promoting cytosolic localization. Most Rab GTPases contain a lipid modification site at the C-terminus, with sequence motifs CC, CXC, or CCX. Lipid binding is essential for membrane attachment, a key feature of most Rab proteins. Due to the presence of truncated sequences in this CD, the lipid modification site is not available for annotation.

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 433660831   5 DARMLASQNIVIILCGNKKDLDADREVTFLEASRFAQENELMFLETSALTGENVEEAFVQCARKI 69
Cdd:cd04113   97 DARTLASPDIVIILVGNKKDLEDDREVTFLEASRFAQENGLLFLETSALTGENVEEAFLKCARSI 161

Ras family; Includes sub-families Ras, Rab, Rac, Ral, Ran, Rap Ypt1 and more. Shares P-loop motif with GTP_EFTU, arf and myosin_head. See pfam00009 pfam00025, pfam00063. As regards Rab GTPases, these are important regulators of vesicle formation, motility and fusion. They share a fold in common with all Ras GTPases: this is a six-stranded beta-sheet surrounded by five alpha-helices.

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 433660831    4 PDARMLASQNIVIILCGNKKDLDADREVTFLEASRFAQENELMFLETSALTGENVEEAFVQCARKILN 71
Cdd:pfam00071  95 EEILRHADENVPIVLVGNKCDLEDQRVVSTEEGEALAKELGLPFMETSAKTNENVEEAFEELAREILK 162

Ras-related in brain (Rab) family of small guanosine triphosphatases (GTPases); Rab GTPases form the largest family within the Ras superfamily. There are at least 60 Rab genes in the human genome, and a number of Rab GTPases are conserved from yeast to humans. Rab GTPases are small, monomeric proteins that function as molecular switches to regulate vesicle trafficking pathways. The different Rab GTPases are localized to the cytosolic face of specific intracellular membranes, where they regulate distinct steps in membrane traffic pathways. In the GTP-bound form, Rab GTPases recruit specific sets of effector proteins onto membranes. Through their effectors, Rab GTPases regulate vesicle formation, actin- and tubulin-dependent vesicle movement, and membrane fusion. GTPase activating proteins (GAPs) interact with GTP-bound Rab and accelerate the hydrolysis of GTP to GDP. Guanine nucleotide exchange factors (GEFs) interact with GDP-bound Rabs to promote the formation of the GTP-bound state. Rabs are further regulated by guanine nucleotide dissociation inhibitors (GDIs), which mask C-terminal lipid binding and promote cytosolic localization. While most unicellular organisms possess 5-20 Rab members, several have been found to possess 60 or more Rabs; for many of these Rab isoforms, homologous proteins are not found in other organisms. Most Rab GTPases contain a lipid modification site at the C-terminus, with sequence motifs CC, CXC, or CCX. Lipid binding is essential for membrane attachment, a key feature of most Rab proteins. Since crystal structures often lack C-terminal residues, the lipid modification site is not available for annotation in many of the CDs in the hierarchy, but is included where possible.

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|...
gi 433660831   5 DARMLASQNIVIILCGNKKDLDADREVTFLEASRFAQENELMFLETSALTGENVEEAFVQCAR 67
Cdd:cd00154   97 ELKEYAPPNIPIILVGNKSDLEDERQVSTEEAQQFAKENGLLFFETSAKTGENVDEAFESLAR 159

Rab-related GTPase family includes Rab5 and Rab22; regulates early endosome fusion; The Rab5-related subfamily includes Rab5 and Rab22 of mammals, Ypt51/Ypt52/Ypt53 of yeast, and RabF of plants. The members of this subfamily are involved in endocytosis and endocytic-sorting pathways. In mammals, Rab5 GTPases localize to early endosomes and regulate fusion of clathrin-coated vesicles to early endosomes and fusion between early endosomes. In yeast, Ypt51p family members similarly regulate membrane trafficking through prevacuolar compartments. GTPase activating proteins (GAPs) interact with GTP-bound Rab and accelerate the hydrolysis of GTP to GDP. Guanine nucleotide exchange factors (GEFs) interact with GDP-bound Rabs to promote the formation of the GTP-bound state. Rabs are further regulated by guanine nucleotide dissociation inhibitors (GDIs), which facilitate Rab recycling by masking C-terminal lipid binding and promoting cytosolic localization. Most Rab GTPases contain a lipid modification site at the C-terminus, with sequence motifs CC, CXC, or CCX. Lipid binding is essential for membrane attachment, a key feature of most Rab proteins. Due to the presence of truncated sequences in this CD, the lipid modification site is not available for annotation.

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|.
gi 433660831  10 ASQNIVIILCGNKKDLDADREVTFLEASRFAQENELMFLETSALTGENVEEAFVQCARKIL 70
Cdd:cd01860  103 GPPNIVIALAGNKADLESKRQVSTEEAQEYADENGLLFMETSAKTGENVNELFTEIARKLP 163

Rab GTPase family 2 (Rab2); Rab2 is localized on cis-Golgi membranes and interacts with Golgi matrix proteins. Rab2 is also implicated in the maturation of vesicular tubular clusters (VTCs), which are microtubule-associated intermediates in transport between the ER and Golgi apparatus. In plants, Rab2 regulates vesicle trafficking between the ER and the Golgi bodies and is important to pollen tube growth. GTPase activating proteins (GAPs) interact with GTP-bound Rab and accelerate the hydrolysis of GTP to GDP. Guanine nucleotide exchange factors (GEFs) interact with GDP-bound Rabs to promote the formation of the GTP-bound state. Rabs are further regulated by guanine nucleotide dissociation inhibitors (GDIs), which facilitate Rab recycling by masking C-terminal lipid binding and promoting cytosolic localization. Most Rab GTPases contain a lipid modification site at the C-terminus, with sequence motifs CC, CXC, or CCX. Lipid binding is essential for membrane attachment, a key feature of most Rab proteins. Due to the presence of truncated sequences in this CD, the lipid modification site is not available for annotation.

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 433660831   5 DARMLASQNIVIILCGNKKDLDADREVTFLEASRFAQENELMFLETSALTGENVEEAFVQCARKILNK 72
Cdd:cd01866  101 DARQHSNSNMTIMLIGNKCDLESRREVSYEEGEAFAREHGLIFMETSAKTASNVEEAFINTAKEIYDK 168

Rab GTPase family 1 includes the yeast homolog Ypt1; Rab1/Ypt1 subfamily. Rab1 is found in every eukaryote and is a key regulatory component for the transport of vesicles from the ER to the Golgi apparatus. Studies on mutations of Ypt1, the yeast homolog of Rab1, showed that this protein is necessary for the budding of vesicles of the ER as well as for their transport to, and fusion with, the Golgi apparatus. GTPase activating proteins (GAPs) interact with GTP-bound Rab and accelerate the hydrolysis of GTP to GDP. Guanine nucleotide exchange factors (GEFs) interact with GDP-bound Rabs to promote the formation of the GTP-bound state. Rabs are further regulated by guanine nucleotide dissociation inhibitors (GDIs), which facilitate Rab recycling by masking C-terminal lipid binding and promoting cytosolic localization. Most Rab GTPases contain a lipid modification site at the C-terminus, with sequence motifs CC, CXC, or CCX. Lipid binding is essential for membrane attachment, a key feature of most Rab proteins. Due to the presence of truncated sequences in this CD, the lipid modification site is not available for annotation.

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|...
gi 433660831  10 ASQNIVIILCGNKKDLDADREVTFLEASRFAQENELMFLETSALTGENVEEAFVQCARKILNK 72
Cdd:cd01869  104 ASENVNKLLVGNKCDLTDKKVVDYTEAKEFADELGIPFLETSAKNATNVEEAFMTMAREIKKR 166

Rab GTPase families 8, 10, 13 (Rab8, Rab10, Rab13); Rab8/Sec4/Ypt2 are known or suspected to be involved in post-Golgi transport to the plasma membrane. It is likely that these Rabs have functions that are specific to the mammalian lineage and have no orthologs in plants. Rab8 modulates polarized membrane transport through reorganization of actin and microtubules, induces the formation of new surface extensions, and has an important role in directed membrane transport to cell surfaces. The Ypt2 gene of the fission yeast Schizosaccharomyces pombe encodes a member of the Ypt/Rab family of small GTP-binding proteins, related in sequence to Sec4p of Saccharomyces cerevisiae but closer to mammalian Rab8. GTPase activating proteins (GAPs) interact with GTP-bound Rab and accelerate the hydrolysis of GTP to GDP. Guanine nucleotide exchange factors (GEFs) interact with GDP-bound Rabs to promote the formation of the GTP-bound state. Rabs are further regulated by guanine nucleotide dissociation inhibitors (GDIs), which facilitate Rab recycling by masking C-terminal lipid binding and promoting cytosolic localization. Most Rab GTPases contain a lipid modification site at the C-terminus, with sequence motifs CC, CXC, or CCX. Lipid binding is essential for membrane attachment, a key feature of most Rab proteins. Due to the presence of truncated sequences in this CD, the lipid modification site is not available for annotation.

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|...
gi 433660831  10 ASQNIVIILCGNKKDLDADREVTFLEASRFAQENELMFLETSALTGENVEEAFVQCARKILNK 72
Cdd:cd01867  105 ASEDVERMLVGNKCDMEEKRVVSKEEGEALAREYGIKFLETSAKANINVEEAFLTLAKDILKK 167

Rab GTPase family 19 (Rab19); Rab19 subfamily. Rab19 proteins are associated with Golgi stacks. Similarity analysis indicated that Rab41 is closely related to Rab19. However, the function of these Rabs is not yet characterized. GTPase activating proteins (GAPs) interact with GTP-bound Rab and accelerate the hydrolysis of GTP to GDP. Guanine nucleotide exchange factors (GEFs) interact with GDP-bound Rabs to promote the formation of the GTP-bound state. Rabs are further regulated by guanine nucleotide dissociation inhibitors (GDIs), which facilitate Rab recycling by masking C-terminal lipid binding and promoting cytosolic localization. Most Rab GTPases contain a lipid modification site at the C-terminus, with sequence motifs CC, CXC, or CCX. Lipid binding is essential for membrane attachment, a key feature of most Rab proteins. Due to the presence of truncated sequences in this CD, the lipid modification site is not available for annotation.

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 433660831   5 DARMLASQNIVIILCGNKKDLDADREVTFLEASRFAQENELMF-LETSALTGENVEEAFVQCARKI 69
Cdd:cd01864  100 EVEKYGASNVVLLLIGNKCDLEEQREVLFEEACTLAEHYGILAvLETSAKESSNVEEAFLLMATEL 165

Ras subfamily of RAS small GTPases; Similar in fold and function to the bacterial EF-Tu GTPase. p21Ras couples receptor Tyr kinases and G protein receptors to protein kinase cascades

                           10        20        30        40        50        60
                   ....*....|....*....|....*....|....*....|....*....|....*....|...
gi 433660831     7 RMLASQNIVIILCGNKKDLDADREVTFLEASRFAQENELMFLETSALTGENVEEAFVQCARKI 69
Cdd:smart00173  99 RVKDRDDVPIVLVGNKCDLESERVVSTEEGKELARQWGCPFLETSAKERVNVDEAFYDLVREI 161

Rab GTPase family 21 (Rab21); The localization and function of Rab21 are not clearly defined, with conflicting data reported. Rab21 has been reported to localize in the ER in human intestinal epithelial cells, with partial colocalization with alpha-glucosidase, a late endosomal/lysosomal marker. More recently, Rab21 was shown to colocalize with and affect the morphology of early endosomes. In Dictyostelium, GTP-bound Rab21, together with two novel LIM domain proteins, LimF and ChLim, has been shown to regulate phagocytosis. GTPase activating proteins (GAPs) interact with GTP-bound Rab and accelerate the hydrolysis of GTP to GDP. Guanine nucleotide exchange factors (GEFs) interact with GDP-bound Rabs to promote the formation of the GTP-bound state. Rabs are further regulated by guanine nucleotide dissociation inhibitors (GDIs), which facilitate Rab recycling by masking C-terminal lipid binding and promoting cytosolic localization. Most Rab GTPases contain a lipid modification site at the C-terminus, with sequence motifs CC, CXC, or CCX. Lipid binding is essential for membrane attachment, a key feature of most Rab proteins. Due to the presence of truncated sequences in this CD, the lipid modification site is not available for annotation.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|....*...
gi 433660831  13 NIVIILCGNKKDLDADREVTFLEASRFAQENELMFLETSALTGENVEEAFVQCARKIL 70
Cdd:cd04123  105 NISLVIVGNKIDLERQRVVSKSEAEEYAKSVGAKHFETSAKTGKGIEELFLSLAKRMI 162

Ras Homolog Enriched in Brain (RheB) is a small GTPase; Rheb (Ras Homolog Enriched in Brain) subfamily. Rheb was initially identified in rat brain, where its expression is elevated by seizures or by long-term potentiation. It is expressed ubiquitously, with elevated levels in muscle and brain. Rheb functions as an important mediator between the tuberous sclerosis complex proteins, TSC1 and TSC2, and the mammalian target of rapamycin (TOR) kinase to stimulate cell growth. TOR kinase regulates cell growth by controlling nutrient availability, growth factors, and the energy status of the cell. TSC1 and TSC2 form a dimeric complex that has tumor suppressor activity, and TSC2 is a GTPase activating protein (GAP) for Rheb. The TSC1/TSC2 complex inhibits the activation of TOR kinase through Rheb. Rheb has also been shown to induce the formation of large cytoplasmic vacuoles in a process that is dependent on the GTPase cycle of Rheb, but independent of the TOR kinase, suggesting Rheb plays a role in endocytic trafficking that leads to cell growth and cell-cycle progression. Most Ras proteins contain a lipid modification site at the C-terminus, with a typical sequence motif CaaX, where a = an aliphatic amino acid and X = any amino acid. Lipid binding is essential for membrane attachment, a key feature of most Ras proteins.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|.
gi 433660831   7 RMLASQNIVIILCGNKKDLDADREVTFLEASRFAQENELMFLETSALTGENVEEAFvqcaRKILNKIESGE 77
Cdd:cd04137  100 DMLGKESVPIVLVGNKSDLHMERQVSAEEGKKLAESWGAAFLESSAKENENVEEAF----ELLIEEIEKVE 166

Rab GTPase family 30 (Rab30); Rab30 subfamily. Rab30 appears to be associated with the Golgi stack. It is expressed in a wide variety of tissue types and in humans maps to chromosome 11. GTPase activating proteins (GAPs) interact with GTP-bound Rab and accelerate the hydrolysis of GTP to GDP. Guanine nucleotide exchange factors (GEFs) interact with GDP-bound Rabs to promote the formation of the GTP-bound state. Rabs are further regulated by guanine nucleotide dissociation inhibitors (GDIs), which facilitate Rab recycling by masking C-terminal lipid binding and promoting cytosolic localization. Most Rab GTPases contain a lipid modification site at the C-terminus, with sequence motifs CC, CXC, or CCX. Lipid binding is essential for membrane attachment, a key feature of most Rab proteins. Due to the presence of truncated sequences in this CD, the lipid modification site is not available for annotation.

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|.
gi 433660831  10 ASQNIVIILCGNKKDLDADREVTFLEASRFAQENELMFLETSALTGENVEEAFVQCARKIL 70
Cdd:cd04114  109 ANNKVITILVGNKIDLAERREVSQQRAEEFSDAQDMYYLETSAKESDNVEKLFLDLACRLI 169

Rab GTPase family 26 (Rab26); Rab26 subfamily. First identified in rat pancreatic acinar cells, Rab26 is believed to play a role in recruiting mature granules to the plasma membrane upon beta-adrenergic stimulation. Rab26 belongs to the Rab functional group III, which are considered key regulators of intracellular vesicle transport during exocytosis. GTPase activating proteins (GAPs) interact with GTP-bound Rab and accelerate the hydrolysis of GTP to GDP. Guanine nucleotide exchange factors (GEFs) interact with GDP-bound Rabs to promote the formation of the GTP-bound state. Rabs are further regulated by guanine nucleotide dissociation inhibitors (GDIs), which facilitate Rab recycling by masking C-terminal lipid binding and promoting cytosolic localization. Most Rab GTPases contain a lipid modification site at the C-terminus, with sequence motifs CC, CXC, or CCX. Lipid binding is essential for membrane attachment, a key feature of most Rab proteins.

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|
gi 433660831  10 ASQNIVIILCGNKKDLDADREVTFLEASRFAQENELMFLETSALTGENVEEAFVQCARKI 69
Cdd:cd04112  103 AQSDVVIMLLGNKADMSGERVVKREDGERLAKEYGVPFMETSAKTGLNVELAFTAVAKEL 162

R-Ras2/TC21, M-Ras/R-Ras3; The M-Ras/R-Ras-like subfamily contains R-Ras2/TC21, M-Ras/R-Ras3, and related members of the Ras family. M-Ras is expressed in lympho-hematopoetic cells. It interacts with some of the known Ras effectors, but appears to also have its own effectors. Expression of mutated M-Ras leads to transformation of several types of cell lines, including hematopoietic cells, mammary epithelial cells, and fibroblasts. Overexpression of M-Ras is observed in carcinomas from breast, uterus, thyroid, stomach, colon, kidney, lung, and rectum. In addition, expression of a constitutively active M-Ras mutant in murine bone marrow induces a malignant mast cell leukemia that is distinct from the monocytic leukemia induced by H-Ras. TC21, along with H-Ras, has been shown to regulate the branching morphogenesis of ureteric bud cell branching in mice. Most Ras proteins contain a lipid modification site at the C-terminus, with a typical sequence motif CaaX, where a = an aliphatic amino acid and X = any amino acid. Lipid binding is essential for membrane attachment, a key feature of most Ras proteins. Due to the presence of truncated sequences in this CD, the lipid modification site is not available for annotation.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|....
gi 433660831  16 IILCGNKKDLDADREVTFLEASRFAQENELMFLETSALTGENVEEAFVQCARKI 69
Cdd:cd04145  110 MILVGNKADLEHQRQVSREEGQELARQLKIPYIETSAKDRVNVDKAFHDLVRVI 163

Rab GTPase family 7 (Rab7); Rab7 subfamily. Rab7 is a small Rab GTPase that regulates vesicular traffic from early to late endosomal stages of the endocytic pathway. The yeast Ypt7 and mammalian Rab7 are both involved in transport to the vacuole/lysosome, whereas Ypt7 is also required for homotypic vacuole fusion. Mammalian Rab7 is an essential participant in the autophagic pathway for sequestration and targeting of cytoplasmic components to the lytic compartment. Mammalian Rab7 is also proposed to function as a tumor suppressor. GTPase activating proteins (GAPs) interact with GTP-bound Rab and accelerate the hydrolysis of GTP to GDP. Guanine nucleotide exchange factors (GEFs) interact with GDP-bound Rabs to promote the formation of the GTP-bound state. Rabs are further regulated by guanine nucleotide dissociation inhibitors (GDIs), which facilitate Rab recycling by masking C-terminal lipid binding and promoting cytosolic localization. Most Rab GTPases contain a lipid modification site at the C-terminus, with sequence motifs CC, CXC, or CCX. Lipid binding is essential for membrane attachment, a key feature of most Rab proteins. Due to the presence of truncated sequences in this CD, the lipid modification site is not available for annotation.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|....*..
gi 433660831  17 ILCGNKKDLDADREVTFLEASRFAQENELM-FLETSALTGENVEEAFVQCARKILNK 72
Cdd:cd01862  113 VVLGNKIDLEEKRQVSTKKAQQWCKSKGNIpYFETSAKEAINVDQAFETIARLALEQ 169

Rab GTPase-like family 4 (Rab-like4); RabL4 (Rab-like4) subfamily. RabL4s are novel proteins that have high sequence similarity with Rab family members, but display features that are distinct from Rabs, and have been termed Rab-like. As in other Rab-like proteins, RabL4 lacks a prenylation site at the C-terminus. The specific function of RabL4 remains unknown.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|.
gi 433660831  17 ILCGNKKDLDADREVTFLEASRFAQENELMFLETSALTGENVEEAFVQCAR 67
Cdd:cd04101  114 VLVGNKCDLTDRREVDAAQAQALAQANTLKFYETSAKEGVGYEAPFLSLAR 164

Rab GTPase family 27a (Rab27a); The Rab27a subfamily consists of Rab27a and its highly homologous isoform, Rab27b. Unlike most Rab proteins whose functions remain poorly defined, Rab27a has many known functions. Rab27a has multiple effector proteins, and depending on which effector it binds, Rab27a has different functions as well as tissue distribution and/or cellular localization. Putative functions have been assigned to Rab27a when associated with the effector proteins Slp1, Slp2, Slp3, Slp4, Slp5, DmSlp, rabphilin, Dm/Ce-rabphilin, Slac2-a, Slac2-b, Slac2-c, Noc2, JFC1, and Munc13-4. Rab27a has been associated with several human diseases, including hemophagocytic syndrome (Griscelli syndrome or GS), Hermansky-Pudlak syndrome, and choroidermia. In the case of GS, a rare, autosomal recessive disease, a Rab27a mutation is directly responsible for the disorder. When Rab27a is localized to the secretory granules of pancreatic beta cells, it is believed to mediate glucose-stimulated insulin secretion, making it a potential target for diabetes therapy. When bound to JFC1 in prostate cells, Rab27a is believed to regulate the exocytosis of prostate- specific markers. GTPase activating proteins (GAPs) interact with GTP-bound Rab and accelerate the hydrolysis of GTP to GDP. Guanine nucleotide exchange factors (GEFs) interact with GDP-bound Rabs to promote the formation of the GTP-bound state. Rabs are further regulated by guanine nucleotide dissociation inhibitors (GDIs), which facilitate Rab recycling by masking C-terminal lipid binding and promoting cytosolic localization. Most Rab GTPases contain a lipid modification site at the C-terminus, with sequence motifs CC, CXC, or CCX. Lipid binding is essential for membrane attachment, a key feature of most Rab proteins. Due to the presence of truncated sequences in this CD, the lipid modification site is not available for annotation.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|....*.
gi 433660831  16 IILCGNKKDLDADREVTFLEASRFAQENELMFLETSALTGENVEEA 61
Cdd:cd04127  123 IVLIGNKADLPDQREVSERQARELADKYGIPYFETSAATGQNVEKA 168

Ras-like protein; Provisional

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|....
gi 433660831  16 IILCGNKKDLDADREVTFLEASRFAQENELMFLETSALTGENVEEAFVQCARKI 69
Cdd:PTZ00369 113 MILVGNKCDLDSERQVSTGEGQELAKSFGIPFLETSAKQRVNVDEAFYELVREI 166

Ras homology family (Rho) of small guanosine triphosphatases (GTPases); Members of the Rho (Ras homology) family include RhoA, Cdc42, Rac, Rnd, Wrch1, RhoBTB, and Rop. There are 22 human Rho family members identified currently. These proteins are all involved in the reorganization of the actin cytoskeleton in response to external stimuli. They also have roles in cell transformation by Ras in cytokinesis, in focal adhesion formation and in the stimulation of stress-activated kinase. These various functions are controlled through distinct effector proteins and mediated through a GTP-binding/GTPase cycle involving three classes of regulating proteins: GAPs (GTPase-activating proteins), GEFs (guanine nucleotide exchange factors), and GDIs (guanine nucleotide dissociation inhibitors). Most Rho proteins contain a lipid modification site at the C-terminus, with a typical sequence motif CaaX, where a = an aliphatic amino acid and X = any amino acid. Lipid binding is essential for membrane attachment, a key feature of most Rho proteins. Since crystal structures often lack C-terminal residues, this feature is not available for annotation in many of the CDs in the hierarchy.

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 433660831  11 SQNIVIILCGNKKDLDADRE-----------VTFLEASRFAQE-NELMFLETSALTGENVEEAFVQCAR 67
Cdd:cd00157  102 CPNVPIILVGTKIDLRDDGNtlkklekkqkpITPEEGEKLAKEiGAVKYMECSALTQEGLKEVFDEAIR 170

Ras GTPase family containing H-Ras,N-Ras and K-Ras4A/4B; H-Ras/N-Ras/K-Ras subfamily. H-Ras, N-Ras, and K-Ras4A/4B are the prototypical members of the Ras family. These isoforms generate distinct signal outputs despite interacting with a common set of activators and effectors, and are strongly associated with oncogenic progression in tumor initiation. Mutated versions of Ras that are insensitive to GAP stimulation (and are therefore constitutively active) are found in a significant fraction of human cancers. Many Ras guanine nucleotide exchange factors (GEFs) have been identified. They are sequestered in the cytosol until activation by growth factors triggers recruitment to the plasma membrane or Golgi, where the GEF colocalizes with Ras. Active (GTP-bound) Ras interacts with several effector proteins that stimulate a variety of diverse cytoplasmic signaling activities. Some are known to positively mediate the oncogenic properties of Ras, including Raf, phosphatidylinositol 3-kinase (PI3K), RalGEFs, and Tiam1. Others are proposed to play negative regulatory roles in oncogenesis, including RASSF and NORE/MST1. Most Ras proteins contain a lipid modification site at the C-terminus, with a typical sequence motif CaaX, where a = an aliphatic amino acid and X = any amino acid. Lipid binding is essential for membrane attachment, a key feature of most Ras proteins. Due to the presence of truncated sequences in this CD, the lipid modification site is not available for annotation.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|....
gi 433660831  16 IILCGNKKDLdADREVTFLEASRFAQENELMFLETSALTGENVEEAFVQCARKI 69
Cdd:cd04138  109 MVLVGNKCDL-AARTVSTRQGQDLAKSYGIPYIETSAKTRQGVEEAFYTLVREI 161

Rem, Rem2, Rad, Gem/Kir (RGK) subfamily of Ras GTPases; RGK subfamily. The RGK (Rem, Rem2, Rad, Gem/Kir) subfamily of Ras GTPases are expressed in a tissue-specific manner and are dynamically regulated by transcriptional and posttranscriptional mechanisms in response to environmental cues. RGK proteins bind to the beta subunit of L-type calcium channels, causing functional down-regulation of these voltage-dependent calcium channels, and either termination of calcium-dependent secretion or modulation of electrical conduction and contractile function. Inhibition of L-type calcium channels by Rem2 may provide a mechanism for modulating calcium-triggered exocytosis in hormone-secreting cells, and has been proposed to influence the secretion of insulin in pancreatic beta cells. RGK proteins also interact with and inhibit the Rho/Rho kinase pathway to modulate remodeling of the cytoskeleton. Two characteristics of RGK proteins cited in the literature are N-terminal and C-terminal extensions beyond the GTPase domain typical of Ras superfamily members. The N-terminal extension is not conserved among family members; the C-terminal extension is reported to be conserved among the family and lack the CaaX prenylation motif typical of membrane-associated Ras proteins. However, a putative CaaX motif has been identified in the alignment of the C-terminal residues of this CD.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 433660831  11 SQNIVIILCGNKKDLDADREVTFLEASRFAQENELMFLETSALTGENVEEAFVQCARKILNKIESGELDPERMGSG 86
Cdd:cd04148  104 AEDIPIILVGNKSDLVRSREVSVQEGRACAVVFDCKFIETSAALQHNVDELFEGIVRQVRLRRDSKEKNTRRMASR 179

Rap-like family consists of Rap1, Rap2 and RSR1; The Rap subfamily consists of the Rap1, Rap2, and RSR1. Rap subfamily proteins perform different cellular functions, depending on the isoform and its subcellular localization. For example, in rat salivary gland, neutrophils, and platelets, Rap1 localizes to secretory granules and is believed to regulate exocytosis or the formation of secretory granules. Rap1 has also been shown to localize in the Golgi of rat fibroblasts, zymogen granules, plasma membrane, and microsomal membrane of the pancreatic acini, as well as in the endocytic compartment of skeletal muscle cells and fibroblasts. Rap1 localizes in the nucleus of human oropharyngeal squamous cell carcinomas (SCCs) and cell lines. Rap1 plays a role in phagocytosis by controlling the binding of adhesion receptors (typically integrins) to their ligands. In yeast, Rap1 has been implicated in multiple functions, including activation and silencing of transcription and maintenance of telomeres. Rap2 is involved in multiple functions, including activation of c-Jun N-terminal kinase (JNK) to regulate the actin cytoskeleton and activation of the Wnt/beta-catenin signaling pathway in embryonic Xenopus. A number of effector proteins for Rap2 have been identified, including isoform 3 of the human mitogen-activated protein kinase kinase kinase kinase 4 (MAP4K4) and Traf2- and Nck-interacting kinase (TNIK), and the RalGEFs RalGDS, RGL, and Rlf, which also interact with Rap1 and Ras. RSR1 is the fungal homolog of Rap1 and Rap2. In budding yeasts, it is involved in selecting a site for bud growth, which directs the establishment of cell polarization. The Rho family GTPase Cdc42 and its GEF, Cdc24, then establish an axis of polarized growth. It is believed that Cdc42 interacts directly with RSR1 in vivo. In filamentous fungi such as Ashbya gossypii, RSR1 is a key regulator of polar growth in the hypha. Most Ras proteins contain a lipid modification site at the C-terminus, with a typical sequence motif CaaX, where a = an aliphatic amino acid and X = any amino acid. Lipid binding is essential for membrane attachment, a key feature of most Ras proteins. Due to the presence of truncated sequences in this CD, the lipid modification site is not available for annotation.

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|....
gi 433660831   7 RMLASQNIVIILCGNKKDLDADREVTFLEASRFAQE-NELMFLETSALTGENVEEAFVQCARKI 69
Cdd:cd04136  100 RVKDTEDVPMILVGNKCDLEDERVVSKEEGQNLARQwGNCPFLETSAKSKINVDEIFYDLVRQI 163

Rab GTPase family 35 (Rab35); Rab35 is one of several Rab proteins to be found to participate in the regulation of osteoclast cells in rats. In addition, Rab35 has been identified as a protein that interacts with nucleophosmin-anaplastic lymphoma kinase (NPM-ALK) in human cells. Overexpression of NPM-ALK is a key oncogenic event in some anaplastic large-cell lymphomas; since Rab35 interacts with N|PM-ALK, it may provide a target for cancer treatments. GTPase activating proteins (GAPs) interact with GTP-bound Rab and accelerate the hydrolysis of GTP to GDP. Guanine nucleotide exchange factors (GEFs) interact with GDP-bound Rabs to promote the formation of the GTP-bound state. Rabs are further regulated by guanine nucleotide dissociation inhibitors (GDIs), which facilitate Rab recycling by masking C-terminal lipid binding and promoting cytosolic localization. Most Rab GTPases contain a lipid modification site at the C-terminus, with sequence motifs CC, CXC, or CCX. Lipid binding is essential for membrane attachment, a key feature of most Rab proteins.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|....*
gi 433660831  17 ILCGNKKDlDADREVTFLE-ASRFAQENELMFLETSALTGENVEEAFVQCARKIL 70
Cdd:cd04110  114 VLVGNKND-DPERKVVETEdAYKFAGQMGISLFETSAKENINVEEMFNCITELVL 167

Ras homolog enriched in striatum (Rhes) and activator of G-protein signaling 1 (Dexras1/AGS1); This subfamily includes Rhes (Ras homolog enriched in striatum) and Dexras1/AGS1 (activator of G-protein signaling 1). These proteins are homologous, but exhibit significant differences in tissue distribution and subcellular localization. Rhes is found primarily in the striatum of the brain, but is also expressed in other areas of the brain, such as the cerebral cortex, hippocampus, inferior colliculus, and cerebellum. Rhes expression is controlled by thyroid hormones. In rat PC12 cells, Rhes is farnesylated and localizes to the plasma membrane. Rhes binds and activates PI3K, and plays a role in coupling serpentine membrane receptors with heterotrimeric G-protein signaling. Rhes has recently been shown to be reduced under conditions of dopamine supersensitivity and may play a role in determining dopamine receptor sensitivity. Dexras1/AGS1 is a dexamethasone-induced Ras protein that is expressed primarily in the brain, with low expression levels in other tissues. Dexras1 localizes primarily to the cytoplasm, and is a critical regulator of the circadian master clock to photic and nonphotic input. Most Ras proteins contain a lipid modification site at the C-terminus, with a typical sequence motif CaaX, where a = an aliphatic amino acid and X = any amino acid. Lipid binding is essential for membrane attachment, a key feature of most Ras proteins.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 433660831  14 IVIILCGNKKDLDADREVTFLEASRFAQENEL-MFLETSALTGENVEEAFVQCArkILNKIESgELDPERMGS-GIQYGD 91
Cdd:cd04143  114 IPMVICGNKADRDFPREVQRDEVEQLVGGDENcAYFEVSAKKNSNLDEMFRALF--SLAKLPN-EMSPSLHRKiSVQYGD 190

                         90
                 ....*....|..
gi 433660831  92 A-ALRQLRSPRR 102
Cdd:cd04143  191 AlHKKSRGGSRK 202

GTP-binding nuclear protein Ran; Provisional

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 433660831  12 QNIVIILCGNKKDLdADREVtflEASR--FAQENELMFLETSALTGENVEEAFVQCARKI-----LNKIESGELDP 80
Cdd:PLN03071 116 ENIPIVLCGNKVDV-KNRQV---KAKQvtFHRKKNLQYYEISAKSNYNFEKPFLYLARKLagdpnLHFVESPALAP 187

Ras-related nuclear proteins (Ran)/TC4 family of small GTPases; Ran GTPase is involved in diverse biological functions, such as nuclear transport, spindle formation during mitosis, DNA replication, and cell division. Among the Ras superfamily, Ran is a unique small G protein. It does not have a lipid modification motif at the C-terminus to bind to the membrane, which is often observed within the Ras superfamily. Ran may therefore interact with a wide range of proteins in various intracellular locations. Like other GTPases, Ran exists in GTP- and GDP-bound conformations that interact differently with effectors. Conversion between these forms and the assembly or disassembly of effector complexes requires the interaction of regulator proteins. The intrinsic GTPase activity of Ran is very low, but it is greatly stimulated by a GTPase-activating protein (RanGAP1) located in the cytoplasm. By contrast, RCC1, a guanine nucleotide exchange factor that generates RanGTP, is bound to chromatin and confined to the nucleus. Ran itself is mobile and is actively imported into the nucleus by a mechanism involving NTF-2. Together with the compartmentalization of its regulators, this is thought to produce a relatively high concentration of RanGTP in the nucleus.

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|...
gi 433660831  13 NIVIILCGNKKDLdADREVtflEAS--RFAQENELMFLETSALTGENVEEAFVQCARKILNKI 73
Cdd:cd00877  104 NIPIVLCGNKVDI-KDRKV---KPKqiTFHRKKNLQYYEISAKSNYNFEKPFLWLARKLLGNP 162

Rab GTPase families 18 (Rab18) and 32 (Rab32); Rab38/Rab32 subfamily. Rab32 and Rab38 are members of the Rab family of small GTPases. Human Rab32 was first identified in platelets but it is expressed in a variety of cell types, where it functions as an A-kinase anchoring protein (AKAP). Rab38 has been shown to be melanocyte-specific. GTPase activating proteins (GAPs) interact with GTP-bound Rab and accelerate the hydrolysis of GTP to GDP. Guanine nucleotide exchange factors (GEFs) interact with GDP-bound Rabs to promote the formation of the GTP-bound state. Rabs are further regulated by guanine nucleotide dissociation inhibitors (GDIs), which facilitate Rab recycling by masking C-terminal lipid binding and promoting cytosolic localization. Most Rab GTPases contain a lipid modification site at the C-terminus, with sequence motifs CC, CXC, or CCX. Lipid binding is essential for membrane attachment, a key feature of most Rab proteins.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|...
gi 433660831  17 ILCGNKKDLDADRE-VTFLEASRFAQENELM-FLETSALTGENVEEAFVQCARKILNKIESGELDPERMGSGI 87
Cdd:cd04107  114 LLLANKCDLKKERLaKDPEQMDQFCKENGFIgWFETSAKENINIEEAMRFLVKNILKNDKGLQSPEPDEDNVI 186

small GTP-binding protein domain; Proteins with a small GTP-binding domain recognized by this model include Ras, RhoA, Rab11, translation elongation factor G, translation initiation factor IF-2, tetratcycline resistance protein TetM, CDC42, Era, ADP-ribosylation factors, tdhF, and many others. In some proteins the domain occurs more than once.This model recognizes a large number of small GTP-binding proteins and related domains in larger proteins. Note that the alpha chains of heterotrimeric G proteins are larger proteins in which the NKXD motif is separated from the GxxxxGK[ST] motif (P-loop) by a long insert and are not easily detected by this model. [Unknown function, General]

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....
gi 433660831    9 LASQNIVIILCGNKKDLDADREVTFlEASRFAQENELMFLETSALTGENVEEAF 62
Cdd:TIGR00231 105 HADSGVPIILVGNKIDLKDADLKTH-VASEFAKLNGEPIIPLSAETGKNIDSAF 157

Rab GTPase family 24 (Rab24); Rab24 is distinct from other Rabs in several ways. It exists primarily in the GTP-bound state, having a low intrinsic GTPase activity; it is not efficiently geranyl-geranylated at the C-terminus; it does not form a detectable complex with Rab GDP-dissociation inhibitors (GDIs); and it has recently been shown to undergo tyrosine phosphorylation when overexpressed in vitro. The specific function of Rab24 still remains unknown. It is found in a transport route between ER-cis-Golgi and late endocytic compartments. It is putatively involved in an autophagic pathway, possibly directing misfolded proteins in the ER to degradative pathways. GTPase activating proteins (GAPs) interact with GTP-bound Rab and accelerate the hydrolysis of GTP to GDP. Guanine nucleotide exchange factors (GEFs) interact with GDP-bound Rabs to promote the formation of the GTP-bound state. Rabs are further regulated by guanine nucleotide dissociation inhibitors (GDIs), which facilitate Rab recycling by masking C-terminal lipid binding and promoting cytosolic localization. Most Rab GTPases contain a lipid modification site at the C-terminus, with sequence motifs CC, CXC, or CCX. Lipid binding is essential for membrane attachment, a key feature of most Rab proteins.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|....*
gi 433660831  16 IILCGNKKDL---DAD-REVTFLEASRFAQENELMFLETSALTGENVEEAFVQCA 66
Cdd:cd04118  108 IYLCGTKSDLieqDRSlRQVDFHDVQDFADEIKAQHFETSSKTGQNVDELFQKVA 162

Rab GTPase family 15 (Rab15); Rab15 colocalizes with the transferrin receptor in early endosome compartments, but not with late endosomal markers. It codistributes with Rab4 and Rab5 on early/sorting endosomes, and with Rab11 on pericentriolar recycling endosomes. It is believed to function as an inhibitory GTPase that regulates distinct steps in early endocytic trafficking. GTPase activating proteins (GAPs) interact with GTP-bound Rab and accelerate the hydrolysis of GTP to GDP. Guanine nucleotide exchange factors (GEFs) interact with GDP-bound Rabs to promote the formation of the GTP-bound state. Rabs are further regulated by guanine nucleotide dissociation inhibitors (GDIs), which facilitate Rab recycling by masking C-terminal lipid binding and promoting cytosolic localization. Most Rab GTPases contain a lipid modification site at the C-terminus, with sequence motifs CC, CXC, or CCX. Lipid binding is essential for membrane attachment, a key feature of most Rab proteins. Due to the presence of truncated sequences in this CD, the lipid modification site is not available for annotation.

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 433660831   5 DARMLASQNIVIILCGNKKDLDADREVTFLEASRFAQENELMFLETSALTGENVEEAFVQCARKIL 70
Cdd:cd04117   97 DVDEYAPEGVQKILIGNKADEEQKRQVGDEQGNKLAKEYGMDFFETSACTNKNIKESFTRLTELVL 162

Rab GTPase family 33 includes Rab33A and Rab33B; Rab33B/Rab33A subfamily. Rab33B is ubiquitously expressed in mouse tissues and cells, where it is localized to the medial Golgi cisternae. It colocalizes with alpha-mannose II. Together with the other cisternal Rabs, Rab6A and Rab6A', it is believed to regulate the Golgi response to stress and is likely a molecular target in stress-activated signaling pathways. Rab33A (previously known as S10) is expressed primarily in the brain and immune system cells. In humans, it is located on the X chromosome at Xq26 and its expression is down-regulated in tuberculosis patients. Experimental evidence suggests that Rab33A is a novel CD8+ T cell factor that likely plays a role in tuberculosis disease processes. GTPase activating proteins (GAPs) interact with GTP-bound Rab and accelerate the hydrolysis of GTP to GDP. Guanine nucleotide exchange factors (GEFs) interact with GDP-bound Rabs to promote the formation of the GTP-bound state. Rabs are further regulated by guanine nucleotide dissociation inhibitors (GDIs), which facilitate Rab recycling by masking C-terminal lipid binding and promoting cytosolic localization. Most Rab GTPases contain a lipid modification site at the C-terminus, with sequence motifs CC, CXC, or CCX. Lipid binding is essential for membrane attachment, a key feature of most Rab proteins. Due to the presence of truncated sequences in this CD, the lipid modification site is not available for annotation.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|....*.
gi 433660831  17 ILCGNKKDLDADREVTFLEASRFAQENELMFLETSA---LTGENVEEAFVQCARKI 69
Cdd:cd04115  113 ILVGNKCDLREQIQVPTDLAQRFADAHSMPLFETSAkdpSENDHVEAIFMTLAHKL 168

Ras homolog family, member G (RhoG) of small guanosine triphosphatases (GTPases); RhoG is a GTPase with high sequence similarity to members of the Rac subfamily, including the regions involved in effector recognition and binding. However, RhoG does not bind to known Rac1 and Cdc42 effectors, including proteins containing a Cdc42/Rac interacting binding (CRIB) motif. Instead, RhoG interacts directly with Elmo, an upstream regulator of Rac1, in a GTP-dependent manner and forms a ternary complex with Dock180 to induce activation of Rac1. The RhoG-Elmo-Dock180 pathway is required for activation of Rac1 and cell spreading mediated by integrin, as well as for neurite outgrowth induced by nerve growth factor. Thus RhoG activates Rac1 through Elmo and Dock180 to control cell morphology. RhoG has also been shown to play a role in caveolar trafficking and has a novel role in signaling the neutrophil respiratory burst stimulated by G protein-coupled receptor (GPCR) agonists. Most Rho proteins contain a lipid modification site at the C-terminus, with a typical sequence motif CaaX, where a = an aliphatic amino acid and X = any amino acid. Lipid binding is essential for membrane attachment, a key feature of most Rho proteins.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|..
gi 433660831  13 NIVIILCGNKKDLDADREV------------TFLEASRFAQE-NELMFLETSALTGENVEEAFVQCARKILN 71
Cdd:cd01875  107 NVPILLVGTKKDLRNDADTlkklkeqgqapiTPQQGGALAKQiHAVKYLECSALNQDGVKEVFAEAVRAVLN 178

Rab GTPase families 34 (Rab34) and 36 (Rab36); Rab34/Rab36 subfamily. Rab34, found primarily in the Golgi, interacts with its effector, Rab-interacting lysosomal protein (RILP). This enables its participation in microtubular dynenin-dynactin-mediated repositioning of lysosomes from the cell periphery to the Golgi. A Rab34 (Rah) isoform that lacks the consensus GTP-binding region has been identified in mice. This isoform is associated with membrane ruffles and promotes macropinosome formation. Rab36 has been mapped to human chromosome 22q11.2, a region that is homozygously deleted in malignant rhabdoid tumors (MRTs). However, experimental assessments do not implicate Rab36 as a tumor suppressor that would enable tumor formation through a loss-of-function mechanism. GTPase activating proteins (GAPs) interact with GTP-bound Rab and accelerate the hydrolysis of GTP to GDP. Guanine nucleotide exchange factors (GEFs) interact with GDP-bound Rabs to promote the formation of the GTP-bound state. Rabs are further regulated by guanine nucleotide dissociation inhibitors (GDIs), which facilitate Rab recycling by masking C-terminal lipid binding and promoting cytosolic localization. Most Rab GTPases contain a lipid modification site at the C-terminus, with sequence motifs CC, CXC, or CCX. Lipid binding is essential for membrane attachment, a key feature of most Rab proteins.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|....*.
gi 433660831  13 NIVIILCGNKKDLD--ADREVTFLEASRFAQENELMFLETSALTGENVEEAFVQCA 66
Cdd:cd04108  106 SVLLFLVGTKKDLSspAQYALMEQDAIKLAREMKAEYWAVSALTGENVRDFFFRVA 161

Ras - dorsal-ventral anterior localization (Ras-dva) family; Ras-dva subfamily. Ras-dva (Ras - dorsal-ventral anterior localization) subfamily consists of a set of proteins characterized only in Xenopus leavis, to date. In Xenopus Ras-dva expression is activated by the transcription factor Otx2 and begins during gastrulation throughout the anterior ectoderm. Ras-dva expression is inhibited in the anterior neural plate by factor Xanf1. Downregulation of Ras-dva results in head development abnormalities through the inhibition of several regulators of the anterior neural plate and folds patterning, including Otx2, BF-1, Xag2, Pax6, Slug, and Sox9. Downregulation of Ras-dva also interferes with the FGF-8a signaling within the anterior ectoderm. Most Ras proteins contain a lipid modification site at the C-terminus, with a typical sequence motif CaaX, where a = an aliphatic amino acid and X = any amino acid. Lipid binding is essential for membrane attachment, a key feature of most Ras proteins.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 433660831  16 IILCGNKKDLDADREVTFLEASRFAQ-ENELMFLETSALTGENVEEAFvqcaRKILNKIESgeldPERMGsgiqygdAAL 94
Cdd:cd04147  107 IVVVGNKIDSLAERQVEAADALSTVElDWNNGFVEASAKDNENVTEVF----KELLQQANL----PSWLS-------PAL 171

                         90       100
                 ....*....|....*....|...
gi 433660831  95 RQLRSP------RRAQAPNAQEC 111
Cdd:cd04147  172 RRRRESapseiqRRPPMNKTNSC 194

Rab GTPase family 9 (Rab9); Rab9 is found in late endosomes, together with mannose 6-phosphate receptors (MPRs) and the tail-interacting protein of 47 kD (TIP47). Rab9 is a key mediator of vesicular transport from late endosomes to the trans-Golgi network (TGN) by redirecting the MPRs. Rab9 has been identified as a key component for the replication of several viruses, including HIV1, Ebola, Marburg, and measles, making it a potential target for inhibiting a variety of viruses. GTPase activating proteins (GAPs) interact with GTP-bound Rab and accelerate the hydrolysis of GTP to GDP. Guanine nucleotide exchange factors (GEFs) interact with GDP-bound Rabs to promote the formation of the GTP-bound state. Rabs are further regulated by guanine nucleotide dissociation inhibitors (GDIs), which facilitate Rab recycling by masking C-terminal lipid binding and promoting cytosolic localization. Most Rab GTPases contain a lipid modification site at the C-terminus, with sequence motifs CC, CXC, or CCX. Lipid binding is essential for membrane attachment, a key feature of most Rab proteins. Due to the presence of truncated sequences in this CD, the lipid modification site is not available for annotation.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|....
gi 433660831  17 ILCGNKKDLDaDREVTFLEASRFAQENELM-FLETSALTGENVEEAFVQCARKI 69
Cdd:cd04116  118 VILGNKIDIP-ERQVSTEEAQAWCRDNGDYpYFETSAKDATNVAAAFEEAVRRV 170