RING finger, HC subclass, found in caspases-8 and -10-associated RING finger protein 1 (CARP1) and similar proteins; CARP1, also known as caspase regulator CARP1, FYVE-RING finger protein Momo, RING finger homologous to inhibitor of apoptosis protein (RFI), RING finger protein 34 (RNF34), or RING finger protein RIFF, is a nuclear protein that functions as a specific E3 ubiquitin ligase for the transcriptional coactivator PGC-1alpha, a master regulator of energy metabolism and adaptive thermogenesis in the brown fat cell which negatively regulates brown fat cell metabolism. It is preferentially expressed in esophageal, gastric, and colorectal cancers, suggesting a possible association with the development of digestive tract cancers. It regulates the p53 signaling pathway by degrading 14-3-3 sigma and stabilizing MDM2. CARP1 does not localize to membranes in the cell and is involved in the negative regulation of apoptosis, specifically targeting two initiator caspases, caspase 8 and caspase 10. CARP1 contains an N-terminal FYVE-like domain and a C-terminal C3HC4-type RING-HC finger domain.

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|...
gi 1712927962 351 SDENLCRICMDAIIDCVLLECGHMVTCTKCGKRMSECPICRQYVVRAVHVFKS 403
Cdd:cd16706     2 SDDNLCRICMDAVIDCVLLECGHMVTCTKCGKRMSECPICRQYVVRAVHVFKS 54

RING finger, HC subclass, found in caspases-8 and -10-associated RING finger protein 1 (CARP1) and similar proteins; CARP1, also known as caspase regulator CARP1, FYVE-RING finger protein Momo, RING finger homologous to inhibitor of apoptosis protein (RFI), RING finger protein 34 (RNF34), or RING finger protein RIFF, is a nuclear protein that functions as a specific E3 ubiquitin ligase for the transcriptional coactivator PGC-1alpha, a master regulator of energy metabolism and adaptive thermogenesis in the brown fat cell which negatively regulates brown fat cell metabolism. It is preferentially expressed in esophageal, gastric, and colorectal cancers, suggesting a possible association with the development of digestive tract cancers. It regulates the p53 signaling pathway by degrading 14-3-3 sigma and stabilizing MDM2. CARP1 does not localize to membranes in the cell and is involved in the negative regulation of apoptosis, specifically targeting two initiator caspases, caspase 8 and caspase 10. CARP1 contains an N-terminal FYVE-like domain and a C-terminal C3HC4-type RING-HC finger domain.

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|...
gi 1712927962 351 SDENLCRICMDAIIDCVLLECGHMVTCTKCGKRMSECPICRQYVVRAVHVFKS 403
Cdd:cd16706     2 SDDNLCRICMDAVIDCVLLECGHMVTCTKCGKRMSECPICRQYVVRAVHVFKS 54

Zinc finger, C3HC4 type (RING finger);

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*..
gi 1712927962 352 DENLCRICMDAIIDCVLLECGHMVTCTKCGKRM----SECPICRQYV 394
Cdd:pfam13920   1 EDLLCVICLDRPRNVVLLPCGHLCLCEECAERLlrkkKKCPICRQPI 47

RING finger, HC subclass, found in caspases-8 and -10-associated RING finger protein 1 (CARP1) and similar proteins; CARP1, also known as caspase regulator CARP1, FYVE-RING finger protein Momo, RING finger homologous to inhibitor of apoptosis protein (RFI), RING finger protein 34 (RNF34), or RING finger protein RIFF, is a nuclear protein that functions as a specific E3 ubiquitin ligase for the transcriptional coactivator PGC-1alpha, a master regulator of energy metabolism and adaptive thermogenesis in the brown fat cell which negatively regulates brown fat cell metabolism. It is preferentially expressed in esophageal, gastric, and colorectal cancers, suggesting a possible association with the development of digestive tract cancers. It regulates the p53 signaling pathway by degrading 14-3-3 sigma and stabilizing MDM2. CARP1 does not localize to membranes in the cell and is involved in the negative regulation of apoptosis, specifically targeting two initiator caspases, caspase 8 and caspase 10. CARP1 contains an N-terminal FYVE-like domain and a C-terminal C3HC4-type RING-HC finger domain.

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|...
gi 1712927962 351 SDENLCRICMDAIIDCVLLECGHMVTCTKCGKRMSECPICRQYVVRAVHVFKS 403
Cdd:cd16706     2 SDDNLCRICMDAVIDCVLLECGHMVTCTKCGKRMSECPICRQYVVRAVHVFKS 54

RING finger, HC subclass, found in caspases-8 and -10-associated RING finger protein CARP-1, CARP-2 and similar proteins; The CARP subfamily includes CARP-1 and CARP-2 proteins, both of which are E3 ubiquitin ligases that ubiquitinate apical caspases and target them for proteasome-mediated degradation. As a novel group of caspase regulators with a FYVE-type zinc finger domain, they do not localize to membranes in the cell and are involved in the negative regulation of apoptosis, specifically targeting two initiator caspases, caspase 8, and caspase 10. Moreover, they stabilize MDM2 by inhibiting MDM2 self-ubiquitination, as well as by targeting 14-3-3sigma for degradation. They work together with MDM2 to enhance p53 degradation, thereby inhibiting p53-mediated cell death. CARPs contain an N-terminal FYVE-like domain that can serve as a membrane-targeting or endosome localizing signal and a C-terminal C3HC4-type RING-HC finger domain.

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*...
gi 1712927962 354 NLCRICMDAIIDCVLLECGHMVTCTKCGKRMSECPICRQYVVRAVHVF 401
Cdd:cd16500     1 DLCKICMDAAIDCVLLECGHMVTCTDCGKKLSECPICRQYVVRVVHFF 48

RING finger, HC subclass, found in inhibitor of apoptosis proteins (IAPs); IAPs are frequently overexpressed in cancer and associated with tumor cell survival, chemoresistance, disease progression, and poor prognosis. They function primarily as negative regulators of cell death. They regulate caspases and apoptosis through the inhibition of specific members of the caspase family of cysteine proteases. In addition, IAPs has been implicated in a multitude of other cellular processes, including inflammatory signalling and immunity, mitogenic kinase signalling, proliferation and mitosis, as well as cell invasion and metastasis. IAPs in this family includes cellular inhibitor of apoptosis protein c-IAP1 (BIRC2) and c-IAP2 (BIRC3), XIAP (BIRC4), BIRC7, and BIRC8, all of which contain three N-terminal baculoviral IAP repeat (BIR) domains that enable interactions with proteins, a ubiquitin-association (UBA) domain that is responsible for the binding of polyubiquitin (polyUb), and a C3HC4-type RING-HC finger at the carboxyl terminus that is required for ubiquitin ligase activity. The UBA domain is only absent in mammalian homologs of BIRC7. Moreover, c-IAPs contains an additional caspase activation and recruitment domain (CARD) between the UBA and C3HC4-type RING-HC domains. The CARD domain may serve as a protein interaction surface.

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|
gi 1712927962 353 ENLCRICMDAIIDCVLLECGHMVTCTKCGKRMSECPICRQ 392
Cdd:cd16510     1 EKLCKICMDREVNIVFLPCGHLVTCAQCAASLRKCPICRT 40

RING finger, HC subclass, found in Dictyostelium discoideum Cbl-like protein A (CblA) and similar proteins; CblA is a Dictyostelium homolog of the Cbl proteins which are multi-domain proteins acting as key negative regulators of various receptor and non-receptor tyrosine kinase signaling. CblA upregulates STATc tyrosine phosphorylation by downregulating PTP3, the protein tyrosine phosphatase responsible for dephosphorylating STATc. STATc is a signal transducer and activator of transcription protein. Like other Cbl proteins, CblA contains a tyrosine-kinase-binding domain (TKB), a proline-rich domain, a C3HC4-type RING-HC finger, and an ubiquitin-associated (UBA) domain. TKB, also known as a phosphotyrosine binding PTB domain, is composed of a four helix-bundle, a Ca2+ binding EF-hand and a highly variant SH2 domain. This family also includes Drosophila melanogaster defense repressor 1 (Dnr1) that was identified as an inhibitor of Dredd activity in the absence of a microbial insult in Drosophila S2 cells. It inhibits the Drosophila initiator caspases Dredd and Dronc. Moreover, Dnr1 acts as a negative regulator of the Imd (immune deficiency) innate immune-response pathway. Its mutations cause neurodegeneration in Drosophila by activating the innate immune response in the brain. Dnr1 contains a FERM N-terminal domain followed by a region rich in glutamine and serine residues, a central FERM domain, and a C-terminal C3HC4-type RING-HC finger.

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                  ....*....|....*....|....*....|....*....|....*....|
gi 1712927962 352 DENLCRICMDAIIDCVLLECGHMVTCTKCGKRMSECPICRQYVVRAVHVF 401
Cdd:cd16501     4 DADLCVVCMDAPIDTVFLECGHLACCRLCSKRLRVCPICRQPISRVVRIF 53

Zinc finger, C3HC4 type (RING finger);

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*..
gi 1712927962 352 DENLCRICMDAIIDCVLLECGHMVTCTKCGKRM----SECPICRQYV 394
Cdd:pfam13920   1 EDLLCVICLDRPRNVVLLPCGHLCLCEECAERLlrkkKKCPICRQPI 47

RING finger, HC subclass, found in apoptosis protein c-IAP1, c-IAP2, livin, and similar proteins; The cellular inhibitor of apoptosis protein c-IAPs function as ubiquitin E3 ligases that mediate the ubiquitination of substrates involved in apoptosis, nuclear factor-kappaB (NF-kappaB) signaling, and oncogenesis. Unlike other IAPs, such as XIAP, c-IAPs exhibit minimal binding to caspases and may not play an important role in the inhibition of these proteases. c-IAP1, also known as baculoviral IAP repeat-containing protein BIRC2, IAP-2, RING finger protein 48, or TNFR2-TRAF-signaling complex protein 2, is a potent regulator of the tumor necrosis factor (TNF) receptor family and NF-kappaB signaling pathways in the cytoplasm. It can also regulate E2F1 transcription factor-mediated control of cyclin transcription in the nucleus. c-IAP2, also known as BIRC3, IAP-1, apoptosis inhibitor 2 (API2), or IAP homolog C, also influences ubiquitin-dependent pathways that modulate innate immune signalling by activation of NF-kappaB. c-IAPs contain three N-terminal baculoviral IAP repeat (BIR) domains that enable interactions with proteins, a ubiquitin-association (UBA) domain that is responsible for the binding of polyubiquitin (polyUb), a caspase activation and recruitment domain (CARD) that serves as a protein interaction surface, and a C3HC4-type RING-HC finger at the carboxyl terminus that is required for ubiquitin ligase activity. Livin, also known as baculoviral IAP repeat-containing protein 7 (BIRC7), kidney inhibitor of apoptosis protein (KIAP), melanoma inhibitor of apoptosis protein (ML-IAP), or RING finger protein 50, was identified as the melanoma IAP. It plays crucial roles in apoptosis, cell proliferation, and cell cycle control. Its anti-apoptotic activity is regulated by the inhibition of caspase-3, -7, and -9. Its E3 ubiquitin-ligase-like activity promotes degradation of Smac/DIABLO, a critical endogenous regulator of all IAPs. Unlike other family members, mammalian livin contains a single BIR domain and a C3HC4-type RING-HC finger. The UBA domain can be detected in non-mammalian homologs of livin.

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1712927962 352 DENLCRICMDAIIDCVLLECGHMVTCTKCGKRMSECPICRQYVVRAVHVFKS 403
Cdd:cd16713     6 EERTCKVCMDKEVSIVFIPCGHLVVCTECAPSLRKCPICRATIKGTVRTFLS 57

FYVE-like domain found in caspase regulator CARP2 and similar proteins; CARP2, also termed E3 ubiquitin-protein ligase rififylin, or caspases-8 and -10-associated RING finger protein 2, or FYVE-RING finger protein Sakura (Fring), or RING finger and FYVE-like domain-containing protein 1, or RING finger protein 189, or RING finger protein 34-like, is a novel caspase regulator containing a FYVE-type zinc finger domain. It regulates the p53 signaling pathway through degrading 14-3-3 sigma and stabilizing MDM2. CARP2 does not localize to membranes in the cell and is involved in the negative regulation of apoptosis, specifically targeting two initiator caspases, caspase 8 and caspase 10, which are distinguished from other FYVE-type proteins. Moreover, CARP2 has an altered sequence in the basic ligand binding patch and lack the WxxD (x for any residue) motif that is conserved only in phosphoinositide binding FYVE domains. Thus it belongs to a family of unique FYVE-type domains called FYVE-like domains. In addition to the N-terminal FYVE-like domain, CARP2 harbors a C-terminal RING domain.

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                  ....*....|....*....|....*....|....*....|....*...
gi 1712927962  60 QLCKACGLAFSVFRRKHICCDCKKSFCALCSVLQEN-LRCCTTCHLLR 106
Cdd:cd15770     2 ISCKACGIRFASCARKHPCMDCKKNYCTACSSQAENgPSLCQLCQRFR 49

RING finger, HC subclass, found in Arabidopsis thaliana protein XB3 homolog 5 (XBAT35) and similar proteins; XBAT35, also known as ankyrin repeat domain and RING finger-containing protein XBAT35, or RING-type E3 ubiquitin transferase XBAT35, has no E3 ubiquitin-protein ligase activity observed when associated with the E2 enzyme UBC8 in vitro. It contains a typical C3HC4-type RING-HC finger.

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                  ....*....|....*....|....*....|....*....|....*....|....
gi 1712927962 352 DENLCRICMDAIIDCVLLECGHMVTCTKCGKRM----SECPICRQYVVRAVHVF 401
Cdd:cd23129     1 QRDECVVCMDAPRDAVCVPCGHVAGCMSCLKALmqssPLCPICRAPVRQVIKVY 54

RING finger, HC subclass, found in leucine-rich repeat and sterile alpha motif-containing protein 1 (LRSAM1) and similar proteins; LRSAM1, also known as Tsg101-associated ligase (TAL), or RIFLE, is an E3 ubiquitin-protein ligase that physically associates with, and selectively ubiquitylates, Tsg101, an E2-like molecule that regulates vesicular trafficking processes in yeast and mammals. It regulates a Tsg101-associated complex responsible for the sorting of cargo into cytoplasm-containing vesicles that bud at the multivesicular body and at the plasma membrane. LRSAM1 is a multidomain protein containing an N-terminal leucine-rich repeat (LRR), followed by several recognizable motifs, including an ezrin-radixin-moezin (ERM) domain, a coiled-coil (CC) region, a SAM domain, and a C-terminal C3HC4-type RING-HC finger domain.

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                  ....*....|....*....|....*....|....*....|...
gi 1712927962 353 ENLCRICMDAIIDCVLLECGHMVTCTKCGKRMSECPICRQYVV 395
Cdd:cd16515     1 ESECVVCMDAESQVIFLPCGHVCCCQTCSSSLSTCPLCRADIT 43

RING finger, HC subclass, found in myosin regulatory light chain interacting protein (MYLIP) and similar proteins; MYLIP, also known as inducible degrader of the low-density lipoprotein (LDL)-receptor (IDOL), or MIR, is an E3 ubiquitin-protein ligase that mediates ubiquitination and subsequent proteasomal degradation of myosin regulatory light chain (MRLC), LDLR, VLDLR, and LRP8. Its activity depends on E2 ubiquitin-conjugating enzymes of the UBE2D family. MYLIP stimulates clathrin-independent endocytosis and acts as a sterol-dependent inhibitor of cellular cholesterol uptake by binding directly to the cytoplasmic tail of the LDLR and promoting its ubiquitination via the UBE2D1/E1 complex. The ubiquitinated LDLR then enters the multivesicular body (MVB) protein-sorting pathway and is shuttled to the lysosome for degradation. Moreover, MYLIP has been identified as a novel ERM-like protein that affects cytoskeleton interactions regulating cell motility, such as neurite outgrowth. The ERM proteins includes ezrin, radixin, and moesin, which are cytoskeletal effector proteins linking actin to membrane-bound proteins at the cell surface. MYLIP contains an ERM-homology domain and a C-terminal C3HC4-type RING-HC finger.

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                  ....*....|....*....|....*....|....*....|....*..
gi 1712927962 355 LCRICMDAIIDCVLLECGHMVTCTKCGKRMSECPICRQYVVRAVHVF 401
Cdd:cd16523     4 LCMVCCEEEINSAFCPCGHMVCCESCAAQLQSCPVCRSRVEHVQHVY 50

RING finger, HC subclass, found in Arabidopsis thaliana MND1-interacting protein 1 (MIP1) and similar proteins; This subfamily includes Arabidopsis thaliana MIP1, RING finger protein 4 (RF4) and RING finger protein 298 (RF298). MIP1 interacts with MND1, HOP2 and XRI1. RF4 and RF298 are putative E3 ubiquitin-protein ligase that may mediate E2-dependent protein ubiquitination. Members of this subfamily contain a typical C3HC4-type RING-HC finger.

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                  ....*....|....*....|....*....|....*....|....*....|
gi 1712927962 356 CRICMDAIIDCVLLECGHMVTCTKC-----GKRMSECPICRQYVVRAVHV 400
Cdd:cd23128     6 CVMCMEEERSVVFLPCAHQVVCSGCndlheKKGMRECPSCRGEIQERIRV 55

FYVE domain found in metazoan PIKfyve, fungal and plant Fab1, and similar proteins; PIKfyve, also termed FYVE finger-containing phosphoinositide kinase, or 1-phosphatidylinositol 3-phosphate 5-kinase, or phosphatidylinositol 3-phosphate 5-kinase (PIP5K3), or phosphatidylinositol 3-phosphate 5-kinase type III (PIPkin-III or type III PIP kinase), is a phosphoinositide 5-kinase that forms a complex with its regulators, the scaffolding protein Vac14 and the lipid phosphatase Fig4. The complex is responsible for synthesizing phosphatidylinositol 3,5-bisphosphate [PtdIns(3,5)P2] from phosphatidylinositol 3-phosphate (PtdIns3P or PI3P). Then phosphatidylinositol-5-phosphate (PtdIns5P) is generated directly from PtdIns(3,5)P2. PtdIns(3,5)P2 and PtdIns5P regulate endosomal trafficking and responses to extracellular stimuli. At this point, PIKfyve is vital in early embryonic development. Moreover, PIKfyve forms a complex with ArPIKfyve (associated regulator of PIKfyve) and SAC3 at the endomembranes, which plays a role in receptor tyrosine kinase (RTK) degradation. The phosphorylation of PIKfyve by AKT can facilitate Epidermal growth factor receptor (EGFR) degradation. In addition, PIKfyve may participate in the regulation of the glutamate transporters EAAT2, EAAT3 and EAAT4, and the cystic fibrosis transmembrane conductance regulator (CFTR). It is also essential for systemic glucose homeostasis and insulin-regulated glucose uptake/GLUT4 translocation in skeletal muscle. It can be activated by protein kinase B (PKB/Akt) and further up-regulates human ether-a-go-go (hERG) channels. This family also includes the yeast and plant orthologs of human PIKfyve, Fab1. PIKfyve and its orthologs share a similar architecture. They contain an N-terminal FYVE domain, a middle region related to the CCT/TCP-1/Cpn60 chaperonins that are involved in productive folding of actin and tubulin, a second middle domain that contains a number of conserved cysteine residues (CCR) unique to this family, and a C-terminal lipid kinase domain related to PtdInsP kinases.

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                  ....*....|....*....|....*....|....*....|....*....|.
gi 1712927962  62 CKACGLAFSVFRRKHICCDCKKSFCALCSVLQ---------ENLRCCTTCH 103
Cdd:cd15725    11 CYECSEKFTTFRRRHHCRLCGQIFCSRCCNQEipgkfigypGDLRVCTYCC 61

FYVE domain found in RUN and FYVE domain-containing protein 1 (RUFY1) and similar proteins; RUFY1, also termed FYVE-finger protein EIP1, or La-binding protein 1, or Rab4-interacting protein (Rabip4), or Zinc finger FYVE domain-containing protein 12 (ZFY12), a human homologue of mouse Rabip4, an effector of Rab4 GTPase that regulates recycling of endocytosed cargo. RUFY1 is an endosomal protein that functions as a dual effector of Rab4 and Rab14 and is involved in efficient recycling of transferrin (Tfn). It is a downstream effector of Etk, a downstream tyrosine kinase of PI3-kinase that is involved in regulation of vesicle trafficking. RUFY1 contains an N-terminal RUN domain and a C-terminal FYVE domain with two coiled-coil domains in-between.

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                  ....*....|....*....|....*....|....*....|....*....|.
gi 1712927962  62 CKACGLAFSVFRRKHICCDCKKSFCALCSVLQENL-------RCCTTCHLL 105
Cdd:cd15758    15 CKQCEKEFSISRRKHHCRNCGHIFCNTCSSNELALpsypkpvRVCDSCHTL 65

FYVE domain like superfamily; FYVE domain is a 60-80 residue double zinc finger motif-containing module named after the four proteins, Fab1, YOTB, Vac1, and EEA1. The canonical FYVE domains are distinguished from other zinc fingers by three signature sequences: an N-terminal WxxD motif (x for any residue), the central basic R(R/K)HHCRxCG patch, and a C-terminal RVC motif, which form a compact phosphatidylinositol 3-phosphate (PtdIns3P, also termed PI3P)-binding site. They are found in many membrane trafficking regulators, including EEA1, Hrs, Vac1p, Vps27p, and FENS-1, which locate to early endosomes, specifically bind PtdIns3P, and play important roles in vesicular traffic and in signal transduction. Some proteins, such as rabphilin-3A and alpha-Rab3-interacting molecules (RIMs), are also involved in membrane trafficking and bind to members of the Rab subfamily of GTP hydrolases. However, they contain FYVE-related domains that are structurally similar to the canonical FYVE domains but lack the three signature sequences. At this point, they may not bind to phosphoinositides. In addition, this superfamily also contains the third group of proteins, caspase-associated ring proteins CARP1 and CARP2. They do not localize to membranes in the cell and are involved in the negative regulation of apoptosis, specifically targeting two initiator caspases, caspase 8 and caspase 10, which are distinguished from other FYVE-type proteins. Moreover, these proteins have an altered sequence in the basic ligand binding patch and lack the WxxD motif that is conserved only in phosphoinositide binding FYVE domains. Thus they constitute a family of unique FYVE-type domains called FYVE-like domains. The FYVE domain is structurally similar to the RING domain and the PHD finger. This superfamily also includes ADDz zinc finger domain, which is a PHD-like zinc finger motif that contains two parts, a C2-C2 and a PHD-like zinc finger.

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                  ....*....|....*....|....*....|....*....|....*....|.
gi 1712927962  62 CKACGLAFSVFRRKHICCDCKKSFCALCSV---------LQENLRCCTTCH 103
Cdd:cd00065     2 CMLCGKKFSLFRRRHHCRRCGRVFCSKCSSkklplpsfgSGKPVRVCDSCY 52

Modified RING finger, HC subclass (C3HC5-type), found in mahogunin RING finger protein 1 (MGRN1), RING finger protein 157 (RNF157) and similar proteins; MGRN1, also known as RING finger protein 156 (RNF156), is a cytosolic E3 ubiquitin-protein ligase that inhibits signaling through the G protein-coupled melanocortin receptors-1 (MC1R), -2 (MC2R) and -4 (MC4R) via ubiquitylation-dependent and -independent processes. It suppresses chaperone-associated misfolded protein aggregation and toxicity. MGRN1 interacts with cytosolic prion proteins (PrPs) that are linked with neurodegeneration. It also interacts with expanded polyglutamine proteins, and suppresses misfolded polyglutamine aggregation and cytotoxicity. Moreover, MGRN1 inhibits melanocortin receptor signaling by competition with Galphas, suggesting a novel pathway for melanocortin signaling from the cell surface to the nucleus. MGRN1 also interacts with and ubiquitylates TSG101, a key component of the endosomal sorting complex required for transport (ESCRT)-I, and regulates endosomal trafficking. A null mutation in the gene encoding MGRN1 causes spongiform neurodegeneration, suggesting a link between dysregulation of endosomal trafficking and spongiform neurodegeneration. RNF157 is a cytoplasmic E3 ubiquitin ligase predominantly expressed in the brain. It is a homolog of the E3 ligase mahogunin ring finger-1 (MGRN1). In cultured neurons, it promotes neuronal survival in an E3 ligase-dependent manner. In contrast, it supports growth and maintenance of dendrites independent of its E3 ligase activity. RNF157 interacts with and ubiquitinates the adaptor protein APBB1 (amyloid beta precursor protein-binding, family B, member 1 or Fe65), which regulates neuronal survival, but not dendritic growth downstream of RNF157. The nuclear localization of APBB1 together with its interaction partner RNA-binding protein SART3 (squamous cell carcinoma antigen recognized by T cells 3 or Tip110) is crucial to trigger apoptosis. Both MGRN1 and RNF157 contain a modified C3HC5-type RING-HC finger, and a functionally uncharacterized region, known as domain associated with RING2 (DAR2), N-terminal to the RING finger. The C3HC5-type RING-HC finger is distinguished from typical C3HC4 RING-HC finger due to the existence of the additional cysteine residue in the middle portion of the RING finger domain.

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                  ....*....|....*....|....*....|....*....|..
gi 1712927962 354 NLCRICMDAIIDCVLLECGHMVTCTKCGKRM----SECPICR 391
Cdd:cd16789     1 SECVICLSDPRDTAVLPCRHLCLCSDCAEVLryqsNKCPICR 42

FYVE domain found in early endosome antigen 1 (EEA1) and similar proteins; EEA1, also termed endosome-associated protein p162, or zinc finger FYVE domain-containing protein 2, is an essential component of the endosomal fusion machinery and required for the fusion and maturation of early endosomes in endocytosis. It forms a parallel coiled-coil homodimer in cells. EEA1 serves as the p97 ATPase substrate and the p97 ATPase may regulate the size of early endosomes by governing the oligomeric state of EEA1. It can interact with the GTP-bound form of Rab22a and be involved in endosomal membrane trafficking. EEA1 also functions as an obligate scaffold for angiotensin II-induced Akt activation in early endosomes. It can be phosphorylated by p38 mitogen-activated protein kinase (MAPK) and further regulate mu opioid receptor endocytosis. EEA1 consists of an N-terminal C2H2 Zn2+ finger, four long heptad repeats, and a C-terminal region containing a calmodulin binding (IQ) motif, a Rab5 interaction site, and a FYVE domain. This model corresponds to the FYVE domain that is responsible for binding phosphatidyl inositol-3-phosphate (PtdIns3P or PI3P) on the membrane.

                          10        20
                  ....*....|....*....|....*....
gi 1712927962  62 CKACGLAFSVFRRKHICCDCKKSFCALCS 90
Cdd:cd15730    12 CMACGKGFSVTVRKHHCRQCGNIFCNECS 40

Modified RING finger, HC subclass (C2H2C4-type), found in E3 ubiquitin-protein ligase MDM2, protein MDM4 and similar proteins; MDM2 (also known as HDM2) and MDM4 (also known as MDMX or HDMX) are the primary p53 tumor suppressor negative regulators. They have non-redundant roles in the regulation of p53. MDM2 mainly functions to control p53 stability, while MDM4 controls p53 transcriptional activity. Both MDM2 and MDM4 contain an N-terminal p53-binding domain, a RanBP2-type zinc finger (zf-RanBP2) domain near the central acidic region, and a C-terminal modified C2H2C4-type RING-HC finger. Mdm2 can form homo-oligomers through its RING domain and displays E3 ubiquitin ligase activity that catalyzes the attachment of ubiquitin to p53 as an essential step in the regulation of its levels in cells. Despite its RING domain and structural similarity with MDM2, MDM4 does not homo-oligomerize and lacks ubiquitin-ligase function, but inhibits the transcriptional activity of p53. In addition, both their RING domains are responsible for the hetero-oligomerization, which is crucial for the suppression of P53 activity during embryonic development and the recruitment of E2 ubiquitin-conjugating enzymes. Moreover, MDM2 and MDM4 can be phosphorylated and destabilized in response to DNA damage stress. In response to ribosomal stress, MDM2-mediated p53 ubiquitination and degradation can be inhibited through the interaction with ribosomal proteins L5, L11, and L23. However, MDM4 is not bound to ribosomal proteins, suggesting its different response to regulation by small basic proteins such as ribosomal proteins and ARF.

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                  ....*....|....*....|....*....|....*....|....*....|..
gi 1712927962 354 NLCRICMDAIIDCVLL--ECGHMVTCTKCGKRMSE----CPICRQYVVRAVH 399
Cdd:cd16646     1 DLCVICLSRPRTAAIVhgKTGHQVACYTCAKKLKRrgkpCPVCRRPIQNVIK 52

HC subclass of RING (RING-HC) finger and its variants; The RING finger is a specialized type of Zn-finger of 40 to 60 residues that binds two atoms of zinc. It is defined by the "cross-brace" motif that chelates zinc atoms by eight amino acid residues, typically Cys or His, arranged in a characteristic spacing. Canonical RING motifs have been categorized into two major subclasses, RING-HC (C3HC4-type) and RING-H2 (C3H2C3-type), according to their Cys/His content. There are also many variants of RING fingers. Some have a different Cys/His pattern. Some lack a single Cys or His residue at typical Zn ligand positions, especially, the fourth or eighth zinc ligand is prevalently exchanged for an Asp, which can chelate Zn in a RING finger as well. This family corresponds to the HC subclass of RING (RING-HC) fingers that are characterized by containing C3HC4-type canonical RING-HC fingers or noncanonical RING-HC finger variants, including C4C4-, C3HC3D-, C2H2C4-, and C3HC5-type modified RING-HC fingers. The canonical RING-HC finger has been defined as C-X2-C-X(9-39)-C-X(1-3)-H-X(2-3)-C-X2-C-X(4-48)-C-X2-C. It binds two Zn ions in a unique "cross-brace" arrangement, which distinguishes it from tandem zinc fingers and other similar motifs. RING-HC fingers can be found in a group of diverse proteins with a variety of cellular functions, including oncogenesis, development, viral replication, signal transduction, the cell cycle, and apoptosis. Many of them are ubiquitin-protein ligases (E3s) that serve as scaffolds for binding to ubiquitin-conjugating enzymes (E2s, also referred to as ubiquitin carrier proteins or UBCs) in close proximity to substrate proteins, which enables efficient transfer of ubiquitin from E2 to the substrates.

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                  ....*....|....*....|....*....|....*....|
gi 1712927962 356 CRICMDAIIDCVLLECGHmVTCTKCGKRMSE-----CPIC 390
Cdd:cd16449     3 CPICLERLKDPVLLPCGH-VFCRECIRRLLEsgsikCPIC 41

second RING finger, HC subclass, found in mind bomb 2 (MIB2) and similar proteins; MIB2, also known as novel zinc finger protein (Novelzin), putative NF-kappa-B-activating protein 002N, skeletrophin, or zinc finger ZZ type with ankyrin repeat domain protein 1, is a large, multi-domain E3 ubiquitin-protein ligase that promotes ubiquitination of the cytoplasmic tails of Notch ligands. Especially, it promotes Delta ubiquitylation and endocytosis in Notch activation. Overexpression of MIB2, activates NF-kappaB and interferon-stimulated response element (ISRE) reporter activity. Moreover, MIB2 acts as a novel component of the activated B-cell CLL/lymphoma 10 (BCL10) complex and controls BCL10-dependent NF-kappaB activation. It also functions as a founder myoblast-specific protein that regulates myoblast fusion and muscle stability. MIB2 contains an MZM region with two Mib-Herc2 domains flanking a ZZ zinc finger, a REP region including two tandem Mib repeats, an ANK region that spans ankyrin repeats, and a RNG region consisting of two C3HC4-type RING-HC fingers. This model corresponds to the second RING-HC finger.

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                  ....*....|....*....|....*....|....*....|....*.
gi 1712927962 356 CRICMDAIIDCVLlECGHMvTCTKCGKRMSECPICRQYVVRAVHVF 401
Cdd:cd16728     7 CPICIDNHIKLVF-QCGHG-SCIECSSALKACPICRQAIRERIQIF 50

HRD ubiquitin ligase complex, ER membrane component [Posttranslational modification, protein turnover, chaperones];

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                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1712927962 330 QNRKSMENVSITAdgVKAQLASDENLCRICMDAIIDCVL-------------LECGHMV--TCTKCG-KRMSECPICRQY 393
Cdd:COG5243   266 RATKDLNAMYPTA--TEEQLTNSDRTCTICMDEMFHPDHeplprgldmtpkrLPCGHILhlHCLKNWlERQQTCPICRRP 343

                  ..
gi 1712927962 394 VV 395
Cdd:COG5243   344 VI 345

RING finger, HC subclass, found in RNA-binding protein MEX3D; MEX3D, also known as RING finger and KH domain-containing protein 1 (RKHD1), RING finger protein 193 (RNF193), or TINO, is an RNA-binding phosphoprotein that controls the stability of the transcripts coding for the anti-apoptotic protein BCL-2, and negatively regulates BCL-2 in HeLa cells. MEX3D contains two K homology (KH) domains that provide RNA-binding capacity, and a C-terminal C3HC4-type RING-HC finger. Like other MEX-3 family proteins, MEX3D shuttles between the nucleus and the cytoplasm via the CRM1-dependent export pathway.

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                  ....*....|....*....|....*....|....*....|....*....|.
gi 1712927962 356 CRICMDAIIDCVLLECGHMVTCTKC-----GKRMSECPICRQYVVRAVHVF 401
Cdd:cd16723    13 CVVCFESEVIAALVPCGHNLFCMECairicGKSEPECPACHTPATQAIHIF 63

FYVE-related domain found in RUN and FYVE domain-containing protein 4 (RUFY4) and similar proteins; RUFY4 belongs to the FUFY protein family which is characterized by the presence of an N-terminal RUN domain and a C-terminal FYVE domain. The FYVE domain of RUFY4 resembles the FYVE-related domain as it lacks the WxxD motif (x for any residue). The biological function of RUFY4 still remains unclear.

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                  ....*....|....*....|....*....|....*....|....*....|.
gi 1712927962  61 LCKACGLAFSVFRRKHICCDCKKSFCALCSVLQEN---------LRCCTTC 102
Cdd:cd15745     1 ACAICAKAFSLFRRKYVCRLCGGVVCHSCSSEDLVlsvpdtciyLRVCKTC 51

FYVE domain found in hepatocyte growth factor (HGF)-regulated tyrosine kinase substrate (Hrs) and similar proteins; Hrs, also termed protein pp110, is a tyrosine phosphorylated protein that plays an important role in the signaling pathway of HGF. It is localized to early endosomes and an essential component of the endosomal sorting and trafficking machinery. Hrs interacts with hypertonia-associated protein Trak1, a novel regulator of endosome-to-lysosome trafficking. It can also forms an Hrs/actinin-4/BERP/myosin V protein complex that is required for efficient transferrin receptor (TfR) recycling but not for epidermal growth factor receptor (EGFR) degradation. Moreover, Hrs, together with STAM proteins, STAM1 and STAM2, and EPs15, forms a multivalent ubiquitin-binding complex that sorts ubiquitinated proteins into the multivesicular body pathway, and plays a regulatory role in endocytosis/exocytosis. Furthermore, Hrs functions as an interactor of the neurofibromatosis 2 tumor suppressor protein schwannomin/merlin. It is also involved in the inhibition of citron kinase-mediated HIV-1 budding. Hrs contains a single ubiquitin-interacting motif (UIM) that is crucial for its function in receptor sorting, and a FYVE domain that harbors double Zn2+ binding sites.

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                  ....*....|....*....|....*....|....*....|....*....|....
gi 1712927962  59 GQLCKACGLAFSVFRRKHICCDCKKSFCALCSV---------LQENLRCCTTCH 103
Cdd:cd15720     5 GDECHRCRVQFGVFQRKHHCRACGQVFCGKCSSksstipkfgIEKEVRVCDPCY 58

RING finger, HC subclass, found in RNA-binding protein MEX3C; MEX3C, also known as RING finger and KH domain-containing protein 2 (RKHD2), or RING finger protein 194 (RNF194), is an RNA-binding phosphoprotein that acts as a suppressor of chromosomal instability. It functions as an ubiquitin E3 ligase responsible for the post-transcriptional, HLA-A allotype-specific regulation of MHC class I molecules (MHC-I). It also modifies retinoic acid inducible gene-1 (RIG-I) in stress granules and plays a critical role in eliciting antiviral immune responses. Moreover, MEX3C plays an essential role in normal postnatal growth via enhancing the local expression of insulin-like growth factor 1 (IGF1) in bone. It may also be involved in metabolic regulation of energy balance. MEX3C contains two K homology (KH) domains that provide RNA-binding capacity, and a C-terminal C3HC4-type RING-HC finger. Like other MEX-3 family proteins, MEX3C shuttles between the nucleus and the cytoplasm via the CRM1-dependent export pathway.

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                  ....*....|....*....|....*....|....*....|....*....|.
gi 1712927962 356 CRICMDAIIDCVLLECGHMVTCTKCG-----KRMSECPICRQYVVRAVHVF 401
Cdd:cd16722     4 CVICFENEVIAALVPCGHNLFCMECAnkiceKETPSCPVCQTAVTQAIQIH 54