BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain superfamily; Proteins in this superfamily are characterized by the presence of a common protein-protein interaction motif of about 100 amino acids, known as the BTB/POZ domain. Members include transcription factors, oncogenic proteins, ion channel proteins, and potassium channel tetramerization domain (KCTD) proteins. They have been identified in poxviruses and many eukaryotes, and have diverse functions, such as transcriptional regulation, chromatin remodeling, protein degradation and cytoskeletal regulation. Many BTB/POZ proteins contain one or two additional domains, such as kelch repeats, zinc-finger domains, FYVE (Fab1, YOTB, Vac1, and EEA1) fingers, or ankyrin repeats, among others. These special additional domains or interaction partners provide unique characteristics and functions to BTB/POZ proteins. In ion channel proteins and KCTD proteins, the BTB/POZ domain is also called the tetramerization (T1) domain.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1958672652  17 GEIVQLNVGGTRFSTSRQTLMWIPDSFFSSLLSGRISTLRDETGAIFIDRDPAAFAPILNFLRTKELDLRGVSINVLRHE 96
Cdd:cd18393     1 GEVIHLNVGGKRFSTSRQTLTWIPDSFFSSLLSGRISTLKDETGAIFIDRDPTVFAPILNFLRTKELDPRGIHVSLLLHE 80

                          90       100
                  ....*....|....*....|...
gi 1958672652  97 AEFYGITPLVRRLLLCEELERSS 119
Cdd:cd18393    81 AQFYGITPLVRRLQLCEELDRSS 103

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in SH3KBP1-binding protein 1 (SHKBP1); SHKBP1, also called SETA-binding protein 1, interacts with cathepsin B and participates in tumor necrosis factor (TNF)-induced apoptosis in ovarian cancer cells. It can promote epidermal growth factor receptor (EGFR) signaling by interrupting c-Cbl-CIN85 complex and inhibiting EGFR degradation. It contains a BTB/POZ domain, also known as tetramerization (T1) domain, a versatile protein-protein interaction motif that facilitates homodimerization or heterodimerization. KCTD family BTB domains can adopt a wide range of oligomerization geometries, including homodimerization, tetramerization, and pentamerization.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1958672652  17 GEIVQLNVGGTRFSTSRQTLMWIPDSFFSSLLSGRISTLRDETGAIFIDRDPAAFAPILNFLRTKELDLRGVSINVLRHE 96
Cdd:cd18393     1 GEVIHLNVGGKRFSTSRQTLTWIPDSFFSSLLSGRISTLKDETGAIFIDRDPTVFAPILNFLRTKELDPRGIHVSLLLHE 80

                          90       100
                  ....*....|....*....|...
gi 1958672652  97 AEFYGITPLVRRLLLCEELERSS 119
Cdd:cd18393    81 AQFYGITPLVRRLQLCEELDRSS 103

Broad-Complex, Tramtrack and Bric a brac; Domain in Broad-Complex, Tramtrack and Bric a brac. Also known as POZ (poxvirus and zinc finger) domain. Known to be a protein-protein interaction motif found at the N-termini of several C2H2-type transcription factors as well as Shaw-type potassium channels. Known structure reveals a tightly intertwined dimer formed via interactions between N-terminal strand and helix structures. However in a subset of BTB/POZ domains, these two secondary structures appear to be missing. Be aware SMART predicts BTB/POZ domains without the beta1- and alpha1-secondary structures.

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1958672652   20 VQLNVGGTRFSTSRQTLMWIPDsFFSSLLSGRIStLRDETGAIFIDRDPAAFAPILNFLRTKELDLRGVSINVLRHEAEF 99
Cdd:smart00225   2 VTLVVGGKKFHAHKAVLAAHSP-YFKALFSSDFK-ESDKSEIYLDDVSPEDFRALLNFLYTGKLDLPEENVEELLELADY 79

                           90
                   ....*....|....*
gi 1958672652  100 YGITPLVRrllLCEE 114
Cdd:smart00225  80 LQIPGLVE---LCEE 91

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in SH3KBP1-binding protein 1 (SHKBP1); SHKBP1, also called SETA-binding protein 1, interacts with cathepsin B and participates in tumor necrosis factor (TNF)-induced apoptosis in ovarian cancer cells. It can promote epidermal growth factor receptor (EGFR) signaling by interrupting c-Cbl-CIN85 complex and inhibiting EGFR degradation. It contains a BTB/POZ domain, also known as tetramerization (T1) domain, a versatile protein-protein interaction motif that facilitates homodimerization or heterodimerization. KCTD family BTB domains can adopt a wide range of oligomerization geometries, including homodimerization, tetramerization, and pentamerization.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1958672652  17 GEIVQLNVGGTRFSTSRQTLMWIPDSFFSSLLSGRISTLRDETGAIFIDRDPAAFAPILNFLRTKELDLRGVSINVLRHE 96
Cdd:cd18393     1 GEVIHLNVGGKRFSTSRQTLTWIPDSFFSSLLSGRISTLKDETGAIFIDRDPTVFAPILNFLRTKELDPRGIHVSLLLHE 80

                          90       100
                  ....*....|....*....|...
gi 1958672652  97 AEFYGITPLVRRLLLCEELERSS 119
Cdd:cd18393    81 AQFYGITPLVRRLQLCEELDRSS 103

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium channel tetramerization domain-containing protein 3 (KCTD3) and SH3KBP1-binding protein 1 (SHKBP1); The group of KCTD proteins includes KCTD3 and SHKBP1. KCTD3, also called renal carcinoma antigen NY-REN-45, is a BTB/POZ domain-containing protein that is an accessory subunit of potassium/sodium hyperpolarization-activated cyclic nucleotide-gated channel 3 (HCN3), upregulating its cell-surface expression and current density without affecting its voltage dependence and kinetics. SHKBP1, also called SETA-binding protein 1, interacts with cathepsin B and participates in tumor necrosis factor (TNF)-induced apoptosis in ovarian cancer cells. It can promote epidermal growth factor receptor (EGFR) signaling by interrupting c-Cbl-CIN85 complex and inhibiting EGFR degradation. The BTB/POZ domain, also known as tetramerization (T1) domain, is a versatile protein-protein interaction motif that facilitates homodimerization or heterodimerization. KCTD family BTB domains can adopt a wide range of oligomerization geometries, including homodimerization, tetramerization, and pentamerization.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1958672652  17 GEIVQLNVGGTRFSTSRQTLMWIPDSFFSSLLSGRISTLRDETGAIFIDRDPAAFAPILNFLRTKELDLRGVSINVLRHE 96
Cdd:cd18363     1 GDIINLNVGGKRFSTSRQTLTWIPDSFFTSLLSGRISSLKDETGAIFIDRDPKLFSIILNYLRTKEIDLRNVDISSLRHE 80

                  ....*.
gi 1958672652  97 AEFYGI 102
Cdd:cd18363    81 AEFYGI 86

BTB/POZ domain; In voltage-gated K+ channels this domain is responsible for subfamily-specific assembly of alpha-subunits into functional tetrameric channels. In KCTD1 this domain functions as a transcriptional repressor. It also mediates homomultimerization of KCTD1 and interaction of KCTD1 with the transcription factor AP-2-alpha.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1958672652  20 VQLNVGGTRFSTSRQTLMWIPDSFFSSLLSGRISTLRDETGAIFIDRDPAAFAPILNFLRT--KELDLRGVSINVLRHEA 97
Cdd:pfam02214   1 VKLNVGGTRFETLKSTLTRFPDTRLGRLLELECDDYDDDTNEYFFDRSPKHFETILNFYRTggKLHRPEEVCLDEFLEEA 80

                  ....*...
gi 1958672652  98 EFYGITPL 105
Cdd:pfam02214  81 EFYGLDEL 88

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in Arabidopsis thaliana FH protein interacting protein FIP2 and similar proteins; FIP2 may act as a substrate-specific adaptor of an E3 ubiquitin-protein ligase complex (CUL3-RBX1-BTB) which mediates the ubiquitination and subsequent proteasomal degradation of target proteins. It contains a BTB/POZ domain, also known as tetramerization (T1) domain, which is a versatile protein-protein interaction motif that facilitates homodimerization or heterodimerization.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1958672652  20 VQLNVGGTRFSTSRQTLMWIPDSFFSSLLSGRISTLRDETGAIFIDRDPAAFAPILNFLR---TKELDLRGVSINVLRHE 96
Cdd:cd18376     1 VKLNVGGQKFTTTLDTLTKDPDSMLAAMFSGRHSLKKDEDGSYFIDRDGTHFRHILNYLRdgeVKIPTEDRSVLKELLEE 80

                  ....*....
gi 1958672652  97 AEFYGITPL 105
Cdd:cd18376    81 AEYYQLRGL 89

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium channel tetramerization domain-containing protein 7 (KCTD7); KCTD7 is a BTB/POZ domain-containing protein that has an impact on K+ fluxes, neurotransmitter synthesis, and neuronal function. It functions as a regulator of potassium conductance in neurons, and is involved in the control of excitability of cortical neurons. Mutations in KCTD7 may cause progressive myoclonus epilepsy (PME). The BTB/POZ domain, also known as tetramerization (T1) domain, is a versatile protein-protein interaction motif that facilitates homodimerization or heterodimerization. KCTD family BTB domains can adopt a wide range of oligomerization geometries, including homodimerization, tetramerization, and pentamerization.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1958672652  18 EIVQLNVGGTRFSTSRQTLMWIPDSFFSSLLSGRISTLRDETGAIFIDRDPAAFAPILNFLRTKELDLRGVSINVLrHEA 97
Cdd:cd18366     4 EVVPLNVGGMHFTTRLSTLRKYEDSMLAAMFSGRHHIPKDSEGRYFIDRDGSYFGYILNFLRDGDLPPRERARAVY-KEA 82

                  ....*....
gi 1958672652  98 EFYGITPLV 106
Cdd:cd18366    83 QYYGIGPLI 91

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium channel tetramerization domain-containing proteins KCTD2, KCTD5, and KCTD17, and similar proteins; This subfamily includes potassium channel tetramerization domain-containing proteins KCTD2, KCTD5, and KCTD17, all of which function as adaptors of Cullin3 based ubiquitin E3 ubiquitin ligases. KCTD2 suppresses gliomagenesis by destabilizing c-Myc. KCTD5 is a negative regulator of the AKT pathway, a key signaling cascade frequently deregulated in cancer. KCTD5 does not impact the operation of Kv4.2, Kv3.4, Kv2.1, or Kv1.2 channels. KCTD17 polyubiquitylates trichoplein, a protein involved in ciliogenesis down-regulation. It is a positive regulator of ciliogenesis, playing a crucial role in the initial steps of axoneme extension. A missense mutation in KCTD17 causes autosomal dominant myoclonus-dystonia (M-D). The BTB/POZ domain, also known as tetramerization (T1) domain, is a versatile protein-protein interaction motif that facilitates homodimerization or heterodimerization. KCTD family BTB domains can adopt a wide range of oligomerization geometries, including homodimerization, tetramerization, and pentamerization. KCTD5 and KCTD17 BTB domains form pentamer structures.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1958672652  20 VQLNVGGTRFSTSRQTLMWIPDSFFSSLLSG--RISTLRDETGAIFIDRDPAAFAPILNFLRTKELDL-RGVSINVLRHE 96
Cdd:cd18362     2 VKLNVGGTYFLTTRTTLCRDPKSFLCRLCQEdpDLPSDKDETGAYLIDRDPTYFGPILNYLRHGKLIIdKDLAEEGVLEE 81

                  ....
gi 1958672652  97 AEFY 100
Cdd:cd18362    82 AEFY 85

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium channel tetramerization domain-containing protein 21 (KCTD21); KCTD21, also calledz KCTD containing, Cullin3 adaptor, suppressor of Hedgehog 2 (KCASH2), is a BTB/POZ domain-containing protein that functions as a substrate-specific adaptor of cullin-3, promoting the ubiquitination and degradation of histone deacetylase HDAC1, thereby inhibiting the deacetylation-mediated transcriptional activation of the Hedgehog effectors Gli1 and Gli2. The BTB/POZ domain, also known as tetramerization (T1) domain, is a versatile protein-protein interaction motif that facilitates homodimerization or heterodimerization. KCTD family BTB domains can adopt a wide range of oligomerization geometries, including homodimerization, tetramerization, and pentamerization.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1958672652  20 VQLNVGGTRFSTSRQTLMWIPDSFFSSLLSGRISTLRDETGAIFIDRDPAAFAPILNFLRTKELDLRG--VSINVLRHEA 97
Cdd:cd18395     3 ITLNVGGKLYTTSLATLTRYPDSMLGAMFSGKFPTKKDSQGNCFIDRDGKIFRYILNFLRTSHLDLPEdfQEMGLLKREA 82

                          90
                  ....*....|..
gi 1958672652  98 EFYGITPLVRRL 109
Cdd:cd18395    83 DFYQIQPLIEAL 94

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium channel tetramerization domain-containing protein 2 (KCTD2); KCTD2 is a BTB/POZ domain-containing protein that functions as an adaptor of Cullin3 E3 ubiquitin ligase. It suppresses gliomagenesis by destabilizing c-Myc. The BTB/POZ domain, also known as tetramerization (T1) domain, is a versatile protein-protein interaction motif that facilitates homodimerization or heterodimerization. KCTD family BTB domains can adopt a wide range of oligomerization geometries, including homodimerization, tetramerization, and pentamerization. KCTD5 and KCTD17 BTB domain, highly similar to KCTD2, form pentamer structures.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1958672652  20 VQLNVGGTRFSTSRQTLMWIPDSFFSSLLSG--RISTLRDETGAIFIDRDPAAFAPILNFLR------TKELDLRGVsin 91
Cdd:cd18389     3 VRLNVGGTYFVSTKQTLCRDPKSFLYRLCQEdpDLDSDKDETGAYLIDRDPTYFGPILNYLRhgkliiNKELAEEGV--- 79

                          90
                  ....*....|....*.
gi 1958672652  92 vlRHEAEFYGITPLVR 107
Cdd:cd18389    80 --LEEAEFYNIASLVR 93

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium channel tetramerization domain-containing proteins, KCTD8, KCTD12, KCTD16 and similar proteins; This subfamily of KCTD proteins includes KCTD8, KCTD12 (also called predominantly fetal expressed T1 domain/Pfetin), and KCTD16. They act as auxiliary subunits of GABAB receptors associated with mood disorders. KCTD8 interacts as a tetramer with GABRB1 and GABRB2. KCTD12 regulates agonist potency and kinetics of GABAB receptor signaling. It promotes tumorigenesis by facilitating CDC25B/CDK1/Aurora A-dependent G2/M transition. KCTD16 interacts with amyloid beta precursor protein (APP), a type I transmembrane protein involved in a variety of cellular processes such as cell adhesion, and axon guidance. The BTB/POZ domain, also known as tetramerization (T1) domain, is a versatile protein-protein interaction motif that facilitates homodimerization or heterodimerization. KCTD family BTB domains can adopt a wide range of oligomerization geometries, including homodimerization, tetramerization, and pentamerization.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1958672652  18 EIVQLNVGGTRFSTSRQTLMWIPDSFFSSLLSG--RISTLRDETGAIFIDRDPAAFAPILNFLRTKELDL--------Rg 87
Cdd:cd18367     3 EIVELNVGGQVYTTSLSTLIKDPDSLLGRMFSGknRQELARDSKGRYFLDRDGVLFRYILDYLRNQKLVLpenfpereR- 81

                          90       100
                  ....*....|....*....|..
gi 1958672652  88 vsinvLRHEAEFYGITPLVRRL 109
Cdd:cd18367    82 -----LKREAEYFQLPELVKAL 98

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium channel regulatory protein (KCNRG); KCNRG, also called potassium channel regulator or protein CLLD4, is an endoplasmic reticulum (ER)-associated tumor suppressor that regulates Kv1 family potassium channel proteins by retaining a fraction of the channels in endomembranes. It contains a BTB/POZ domain, also known as tetramerization (T1) domain, which is a versatile protein-protein interaction motif that facilitates homodimerization or heterodimerization.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1958672652  18 EIVQLNVGGTRFSTSRQTLMWIPDSFFSSLLSGRISTLRDETGAIFIDRDPAAFAPILNFLRTKELDL-RGVS-INVLRH 95
Cdd:cd18375     1 ELVTLNVGGKKFTTRPSTLRRFPDSRLARMLDGKDQDFKVVNGQFFVDRDGSLFSYILDYLRTGQLTLpTEFSdYNRLAR 80

                          90
                  ....*....|.
gi 1958672652  96 EAEFYGITPLV 106
Cdd:cd18375    81 EAEFYGLYSLA 91

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in voltage-gated potassium (Kv) channels; Voltage-gated potassium (Kv) channels are composed of alpha subunits, which form the actual conductance pore, and beta subunits, which are auxiliary proteins that associate with alpha subunits to modulate the activity of the Kv channel. This family includes several groups of alpha subunits such as KCNA/Kv1 family of Shaker-type Kv channels, KCNB/Kv2 family of Shab-type Kv channels, KCNC/Kv3 family of Shaw-type Kv channels, KCND/Kv4 family of Shal-type Kv channels, KCNF/Kv5 subfamily of Kv channels, KCNG/Kv6 subfamily of Kv channels, KCNV/Kv8 subfamily of Kv channels, and KCNS/Kv9 subfamily of Kv channels. Kv alpha subunits form functional homo- or hetero-tetrameric channels (typically with other alpha subunits from the same subfamily) through their BTB/POZ domain, also known as tetramerization (T1) domain, which is a versatile protein-protein interaction motif. KCNQ/Kv7 channels are not included in this family, since they do not contain a BTB/POZ domain.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1958672652  20 VQLNVGGTRFSTSRQTLMWIPDSFFSSLLSGRISTLrDETGAIFIDRDPAAFAPILNFLRTKELDL-RGVSINVLRHEAE 98
Cdd:cd18317     1 VVLNVGGTRFELSRSTLLRFPDTRLGKLAKESHAYD-ESTNEYFFDRNPEVFEAILDYYRTGELHLpSNVCPASFKEELE 79

                  ...
gi 1958672652  99 FYG 101
Cdd:cd18317    80 FWG 82

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium channel tetramerization domain-containing protein 14 (KCTD14); KCTD14 is a BTB/POZ domain-containing protein with unknown biological function. KCTD proteins play crucial roles in a variety of fundamental biological processes, such as protein ubiquitination and degradation, suppression of proliferation or transcription, cytoskeleton regulation, tetramerization and gating of ion channels and others. Some KCTD proteins are involved in protein ubiquitination as part of the CRL (Cullin RING Ligase) E3 ligases. The BTB/POZ domain, also known as tetramerization (T1) domain, is a versatile protein-protein interaction motif that facilitates homodimerization or heterodimerization. KCTD family BTB domains can adopt a wide range of oligomerization geometries, including homodimerization, tetramerization, and pentamerization.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1958672652  19 IVQLNVGGTRFSTSRQTLMWIPDSFFSSLLSGRISTLRDETGAIFIDRDPAAFAPILNFLRTKELDLRgvSINVLRHEAE 98
Cdd:cd18371     3 VVSLNVGGHIYTTTLSTLRKFPGSKLAELFNGQPKLRTDSEGRYFIDRDGTYFRYILEYLRTNQVPTQ--HIQEVYKEAL 80

                          90
                  ....*....|.
gi 1958672652  99 FYGITPLVRRL 109
Cdd:cd18371    81 FYDIEPLVKLL 91

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium voltage-gated channel subfamily D member 2 (KCND2); KCND2, also called voltage-gated potassium channel subunit Kv4.2, is a major pore-forming subunit in somatodendritic subthreshold A-type potassium current I(SA) channels. It mediates transmembrane potassium transport in excitable membranes, primarily in the brain. Voltage-gated potassium (Kv) channels are composed of alpha subunits, which form the actual conductance pore, and cytoplasmic beta subunits, which are auxiliary proteins that associate with alpha subunits to modulate the activity of the Kv channel. KCND2 is an alpha subunit that forms functional homo- or hetero-tetrameric channels (with other Kv4/KCND alpha subunits) through its BTB/POZ domain, also known as tetramerization (T1) domain, which is a versatile protein-protein interaction motif. It is modulated by cytoplasmic KChIPs/KCNIPs (Kv-channel interacting proteins), which are small calcium binding proteins with EF-hand-like domains.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1958672652  19 IVQLNVGGTRFSTSRQTLMWIPDSFFSSllSGRISTLRDETGAIFIDRDPAAFAPILNFLRTKELDL-RGVSINVLRHEA 97
Cdd:cd18418     1 LIVLNVSGTRFQTWRNTLERYPDTLLGS--SERDFFYHEETQEYFFDRDPDIFRHILNFYRTGKLHYpRHECISAYDEEL 78

                  ....*..
gi 1958672652  98 EFYGITP 104
Cdd:cd18418    79 AFFGIIP 85

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium channel tetramerization domain-containing protein KCTD8; KCTD8, a BTB/POZ domain-containing protein, is an auxiliary subunit of GABA-B receptors that determine the pharmacology and kinetics of the receptor response. It interacts as a tetramer with GABRB1 and GABRB2. The BTB/POZ domain, also known as tetramerization (T1) domain, is a versatile protein-protein interaction motif that facilitates homodimerization or heterodimerization. KCTD family BTB domains can adopt a wide range of oligomerization geometries, including homodimerization, tetramerization, and pentamerization.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1958672652  18 EIVQLNVGGTRFSTSRQTLMWIPDSFFSSLLSGRISTL--RDETGAIFIDRDPAAFAPILNFLRTKELDL--RGVSINVL 93
Cdd:cd18396     4 EVVELNVGGQVYVTKHSTLLSVPDSTLASMFSRRAARElpRDNRGRFFIDRDGFLFRYVLDYLRDKQLALpdHFPEKERL 83

                          90
                  ....*....|....*.
gi 1958672652  94 RHEAEFYGITPLVRRL 109
Cdd:cd18396    84 LREAEYFQLGDLVKLL 99

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in KCNC/Kv3 subfamily of Shaw-type voltage-dependent potassium channels; Voltage-gated potassium (Kv) channels are composed of alpha subunits, which form the actual conductance pore, and cytoplasmic beta subunits, which are auxiliary proteins that associate with alpha subunits to modulate the activity of the Kv channel. The potassium voltage-gated channel subfamily Kv3, also known as subfamily C, contains four alpha subunit members, Kv3.1 (KCNC1), Kv3.2 (KCNC2), Kv3.3 (KCNC3), and Kv3.4 (KCNC4), which are orthologs of the Shaw gene in Drosophila. Unlike other Kv subfamilies, Kv3 channels typically open only at positive potentials and both, activation and deactivation, in response to changes in voltage are very rapid. They are uniquely associated with the ability of certain neurons to fire action potentials and to release neurotransmitter at high rates of up to 1,000 Hz. Kv3/KCNC subfamily alpha subunits form functional homo- or hetero-tetrameric channels (with other alpha subunits) through their BTB/POZ domain, also known as tetramerization (T1) domain, which is a versatile protein-protein interaction motif.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1958672652  20 VQLNVGGTRFSTSRQTLMWIPDSFFSSLLSGRISTLR--DETGAIFIDRDPAAFAPILNFLRTKEL----DLRGvsiNVL 93
Cdd:cd18379     1 IVINVGGVRHETYKSTLRNLPDTRLAWLTETEASAFDydPVTGEFFFDRHPGVFAQILNYYRTGKLhcpaDVCG---PLF 77

                          90
                  ....*....|
gi 1958672652  94 RHEAEFYGIT 103
Cdd:cd18379    78 EEELAFWGID 87

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium channel tetramerization domain-containing protein 18 (KCTD18); KCTD18 is a BTB/POZ domain-containing protein with with unknown biological function. A duplication of the KCTD18 gene has been found in a patient with epilepsy, developmental delay, and autistic behavior, which may contribute to the phenotype. KCTD proteins play crucial roles in a variety of fundamental biological processes, such as protein ubiquitination and degradation, suppression of proliferation or transcription, cytoskeleton regulation, tetramerization and gating of ion channels and others. Some KCTD proteins are involved in protein ubiquitination as part of the CRL (Cullin RING Ligase) E3 ligases. The BTB/POZ domain, also known as tetramerization (T1) domain, is a versatile protein-protein interaction motif that facilitates homodimerization or heterodimerization. KCTD family BTB domains can adopt a wide range of oligomerization geometries, including homodimerization, tetramerization, and pentamerization.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1958672652  18 EIVQLNVGGTRFSTSRQTLMWIPDSFFSSLLSGRISTLRDETGAIFIDRDPAAFAPILNFLRTK-ELDLRGVSINVLRHE 96
Cdd:cd18372     1 DVLRLNVGGCIYTARRESLCRFKDSMLSSMFSGRFPLKLDESGACVIDRDGRLFKYLLDYLHGElQIPEDEQTRLALQEE 80

                  ....*.
gi 1958672652  97 AEFYGI 102
Cdd:cd18372    81 ADYFGI 86

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in tumor necrosis factor, alpha-induced protein 1, endothelial (TNFAIP1); TNFAIP1, also called BTB/POZ domain-containing adapter for CUL3-mediated RhoA degradation protein 2 (BACURD2), or protein B12, is a BTB/POZ domain-containing protein that is involved in DNA replication, DNA damage repair and cell apoptosis, and is implicated in human diseases including cancer, Alzheimer's disease (AD) and type 2 diabetic nephropathy. The BTB/POZ domain, also known as tetramerization (T1) domain, is a versatile protein-protein interaction motif that facilitates homodimerization or heterodimerization. KCTD family BTB domains can adopt a wide range of oligomerization geometries, including homodimerization, tetramerization, and pentamerization. The BTB domains of other BACURD subfamily members, KCTD10 and KCTD13, form a novel two-fold symmetric tetramer that is distinct from the tetramer formed by voltage-gated potassium (Kv) channels.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1958672652  20 VQLNVGGTRFSTSRQTLMWiPDSFFSSLLSGRISTLRDETGAIFIDRDPAAFAPILNFLRTKELDL--RGVSINVLRHEA 97
Cdd:cd18401     5 VRLNVGGSLYYTTVQVLTR-HDTMLKAMFSGRMEVLTDKEGWILIDRCGKHFGTILNYLRDDTVALpkSRQEIKELMAEA 83

                  ....*....
gi 1958672652  98 EFYGITPLV 106
Cdd:cd18401    84 KYYLIQGLV 92

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium channel tetramerization domain-containing protein 15 (KCTD15); KCTD15 is a BTB/POZ domain-containing protein that plays a role in the regulation of neural crest (NC) formation and other steps in embryonic development. It inhibits AP2 transcriptional activity by interaction with its activation domain. The BTB/POZ domain, also known as tetramerization (T1) domain, is a versatile protein-protein interaction motif that facilitates homodimerization or heterodimerization. KCTD family BTB domains can adopt a wide range of oligomerization geometries, including homodimerization, tetramerization, and pentamerization. The KCTD1 BTB domains, closely related to KCTD15, form pentamers.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1958672652  20 VQLNVGGTRFSTSRQTLMWIPDSFFSSLLSGRISTLRDETGA-IFIDRDPAAFAPILNFLRTKEL----DLRgvSINVLR 94
Cdd:cd18388     4 VHIDVGGHMYTSSLATLTKYPDSRISRLFNGTEPIVLDSLKQhYFIDRDGEIFRYILSFLRTSKLllpeDFK--DFNLLY 81

                          90       100
                  ....*....|....*....|...
gi 1958672652  95 HEAEFYGITPLVRrlllceELER 117
Cdd:cd18388    82 EEAKYYQLQPMVK------ELER 98

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium channel tetramerization domain-containing protein 13 (KCTD13); KCTD13, also called BTB/POZ domain-containing adapter for CUL3-mediated RhoA degradation protein 1 (BACURD1), or TNFAIP1-like protein, is a BTB/POZ domain-containing protein that may function as a substrate-specific adaptor of a BCR (BTB-CUL3-RBX1) E3 ubiquitin-protein ligase complex that mediates the ubiquitination of RhoA, leading to its degradation by the proteasome, thereby regulating the actin cytoskeleton and cell migration. The BTB/POZ domain, also known as tetramerization (T1) domain, is a versatile protein-protein interaction motif that facilitates homodimerization or heterodimerization. KCTD family BTB domains can adopt a wide range of oligomerization geometries, including homodimerization, tetramerization, and pentamerization. The KCTD13 BTB domain forms a novel two-fold symmetric tetramer that is distinct from the tetramer formed by voltage-gated potassium (Kv) channels.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1958672652  20 VQLNVGGTRFSTSRQTLMWiPDSFFSSLLSGRISTLRDETGAIFIDRDPAAFAPILNFLR---------TKELDlrgvsi 90
Cdd:cd18400     4 VKLNVGGSLHYTTVQTLTK-QDTMLKAMFSGRVEVLTDSEGWVLIDRSGRHFGTILNYLRdgsvplpesTRELE------ 76

                          90       100
                  ....*....|....*....|....*..
gi 1958672652  91 NVLRhEAEFYGITPLVRRLLLCEELER 117
Cdd:cd18400    77 ELLG-EARYYLVQGLVEDCQLALQQKR 102

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in Drosophila melanogaster potassium voltage-gated channel protein Shal and similar proteins; Drosophila melanogaster Shal, also called Shaker cognate l or Shal2, is a transient potassium current (I(A)) channel, which is required for maintaining excitability during repetitive firing and normal locomotion in Drosophila. It may play a role in the nervous system and in the regulation of beating frequency in pacemaker cells. Shal mediates the voltage-dependent potassium ion permeability of excitable membranes. Assuming opened or closed conformations in response to the voltage difference across the membrane, the protein forms a potassium-selective channel through which potassium ions may pass in accordance with their electrochemical gradient. Voltage-gated potassium (Kv) channels are composed of alpha subunits, which form the actual conductance pore, and cytoplasmic beta subunits, which are auxiliary proteins that associate with alpha subunits to modulate the activity of the Kv channel. Shal is an alpha subunit that forms functional homo- or hetero-tetrameric channels (with other alpha subunits) through its BTB/POZ domain, also known as tetramerization (T1) domain, which is a versatile protein-protein interaction motif.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1958672652  18 EIVQLNVGGTRFSTSRQTLMWIPDSFFSSllSGRISTLRDETGAIFIDRDPAAFAPILNFLRTKELDL-RGVSINVLRHE 96
Cdd:cd18420    36 EKLIINVSGRRFETWRNTLEKYPDTLLGS--NEREFFYDEETKEYFFDRDPDIFRHILNYYRTGKLHYpKHECLTAYDEE 113

                  ....*...
gi 1958672652  97 AEFYGITP 104
Cdd:cd18420   114 LAFFGIMP 121

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in KCNB/Kv2 subfamily of Shab-type voltage-dependent potassium channels; Voltage-gated potassium (Kv) channels are composed of alpha subunits, which form the actual conductance pore, and cytoplasmic beta subunits, which are auxiliary proteins that associate with alpha subunits to modulate the activity of the Kv channel. The potassium voltage-gated channel subfamily Kv3, also known as subfamily C, contains two alpha subunit members, Kv2.1 (KCNB1) and Kv2.2 (KCNB2), which are orthologs of the Shab gene in Drosophila. They are delayed-rectifier potassium currents in various neurons, although their physiological roles often remain elusive. Kv2/KCNB subfamily alpha subunits form functional homo- or hetero-tetrameric channels (with other alpha subunits) through their BTB/POZ domain, also known as tetramerization (T1) domain, which is a versatile protein-protein interaction motif.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1958672652  20 VQLNVGGTRFSTSRQTLMWIPDSffssllsgRISTLRD----------------ETGAIFIDRDPAAFAPILNFLRTKEL 83
Cdd:cd18378     4 VLLNVGGVRHEVLWRTLDRLPRT--------RLGRLREcnthesllelcddydlEDNEYFFDRHPGAFTSILNFYRTGKL 75

                          90       100       110       120
                  ....*....|....*....|....*....|....*....|....
gi 1958672652  84 DL-RGVSINVLRHEAEFYGItplvrrlllcEELERSSCGSVLFH 126
Cdd:cd18378    76 HMpEEMCVLSFSQELEYWGI----------DEIYLESCCQHRYH 109

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium channel tetramerization domain-containing protein 1 (KCTD1); KCTD1 is a nuclear BTB/POZ domain-containing protein that acts as a transcriptional repressor and mediates protein-protein interactions through a BTB domain. It represses the transcriptional activity of AP-2 family members, including TFAP2A, TFAP2B and TFAP2C to various extent. It also functions as a novel inhibitor of the Wnt signaling pathway. Mutations in KCTD1 cause scalp-ear-nipple (SEN) syndrome. The BTB/POZ domain, also known as tetramerization (T1) domain, is a versatile protein-protein interaction motif that facilitates homodimerization or heterodimerization. KCTD family BTB domains can adopt a wide range of oligomerization geometries, including homodimerization, tetramerization, and pentamerization. The KCTD1 BTB domains form pentamers.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1958672652  20 VQLNVGGTRFSTSRQTLMWIPDSFFSSLLSGRISTLRDETGA-IFIDRDPAAFAPILNFLRTKEL----DLRGVSInvLR 94
Cdd:cd18387     5 VHIDVGGHMYTSSLATLTKYPESRIGRLFDGTEPIVLDSLKQhYFIDRDGQMFRYILNFLRTSKLlipdDFKDYSL--LY 82

                          90
                  ....*....|....*
gi 1958672652  95 HEAEFYGITPLVRRL 109
Cdd:cd18387    83 EEAKYFQLQPMLLEL 97

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in KCNG/Kv6 subfamily of potassium voltage-gated channels; Voltage-gated potassium (Kv) channels are composed of alpha subunits, which form the actual conductance pore, and cytoplasmic beta subunits, which are auxiliary proteins that associate with alpha subunits to modulate the activity of the Kv channel. The potassium voltage-gated channel subfamily Kv6, also known as subfamily G, includes KCNG1 (Kv6.1), KCNG2 (Kv6.2 or KCNF2), KCNG3 (Kv6.3) and KCNG4 (Kv6.4), which are regulatory alpha subunits and do not form functional channels on their own. KCNG1 can form functional heterotetrameric channels with KCNB1 (also known as Kv2.1), and further modulates the delayed rectifier voltage-gated potassium channel activation and deactivation rates of KCNB1. KCNG2, also called cardiac potassium channel subunit, can form functional heterodimeric channels with KCNB1, and further modulates channel activity by shifting the threshold and the half-maximal activation to more negative values. KCNG3, also called voltage-gated potassium channel subunit Kv10.1, is an electrically silent modulatory subunit that can form functional heterotetrameric channels with KCNB1, and further promotes a reduction in the rate of activation and inactivation of the delayed rectifier voltage-gated potassium channel KCNB1. KCNG4 is a silent voltage-gated potassium (KvS) channel subunit that can form functional heterotetrameric channels with KCNB1, and further modulates the delayed rectifier voltage-gated potassium channel activation and deactivation rates of KCNB1.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1958672652  20 VQLNVGGTRFSTSRQTLMWIPDSFFSSLLSGR----ISTLRD----ETGAIFIDRDPAAFAPILNFLRTKELDL-RGVSI 90
Cdd:cd18382     1 VIINVGGARYSLPWSTLDRFPLTRLSRLKACRseddILRVCDdydvERNEFFFDRSPEAFGVILLFLRAGKLRLlREMCA 80

                          90
                  ....*....|..
gi 1958672652  91 NVLRHEAEFYGI 102
Cdd:cd18382    81 LSFQEELAYWGI 92

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium voltage-gated channel subfamily S member 3 (KCNS3); KCNS3, also called delayed-rectifier K(+) channel alpha subunit 3 or voltage-gated potassium channel subunit Kv9.3, is an alpha subunit of voltage-gated potassium channel linked to tissue oxygenation responses. It can form functional heterotetrameric channels with KCNB1 (also known as Kv2.1), and further modulates the delayed rectifier voltage-gated potassium channel activation and deactivation rates of KCNB1. Voltage-gated potassium (Kv) channels are composed of alpha subunits, which form the actual conductance pore, and cytoplasmic beta subunits, which are auxiliary proteins that associate with alpha subunits to modulate the activity of the Kv channel. KCNS3 is a regulatory alpha subunit that cannot form a functional homo-tetrameric channel. It forms hetero-tetrameric channels (with other functional alpha subunits) through its BTB/POZ domain, also known as tetramerization (T1) domain, which is a versatile protein-protein interaction motif.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1958672652  18 EIVQLNVGGTRFSTSRQTLMWIPDSFFSSLLSGR----ISTLRDETGAI----FIDRDPAAFAPILNFLRTKELDL-RGV 88
Cdd:cd18428     1 ELINLNVGGFKQSVDQSTLLRFPHTRLGKLLNCHseeaILELCDDYSVAdkeyYFDRNPSLFRYVLNFYYTGKLHVmEEL 80

                          90
                  ....*....|....*..
gi 1958672652  89 SINVLRHEAEFYGITPL 105
Cdd:cd18428    81 CVFSFCQEIEYWGINEL 97

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in Drosophila melanogaster potassium voltage-gated channel protein Shab and similar proteins; Shab is a slow delayed rectifier voltage-gated potassium channel in Drosophila. It mediates transmembrane potassium transport in excitable membranes. Assuming opened or closed conformations in response to the voltage difference across the membrane, the protein forms a tetrameric potassium-selective channel through which potassium ions may pass in accordance with their electrochemical gradient. Voltage-gated potassium (Kv) channels are composed of alpha subunits, which form the actual conductance pore, and cytoplasmic beta subunits, which are auxiliary proteins that associate with alpha subunits to modulate the activity of the Kv channel. Shab is an alpha subunit that forms functional homo- or hetero-tetrameric channels (with other alpha subunits) through its BTB/POZ domain, also known as tetramerization (T1) domain, which is a versatile protein-protein interaction motif.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1958672652  20 VQLNVGGTRFSTSRQTLMWIPDSffssllsgRISTLRDETG--AI--------------FIDRDPAAFAPILNFLRTKEL 83
Cdd:cd18413     4 VVINVGGVKHEVLWRTLDRMPHT--------RLGKLRDSNTheAIvelcddysladneyFFDRHPRSFASILNFYRTGKL 75

                          90       100
                  ....*....|....*....|...
gi 1958672652  84 DL-RGVSINVLRHEAEFYGITPL 105
Cdd:cd18413    76 HLvEEMCVLAFSDDLEYWGVDEL 98

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium voltage-gated channel subfamily S member 1 (KCNS1); KCNS1, also called delayed-rectifier K(+) channel alpha subunit 1 or voltage-gated potassium channel subunit Kv9.1, is a modulatory alpha subunit of voltage-gated potassium channel that mediates neuropathic pain following nerve injury. It can form functional heterotetrameric channels with KCNB1 (also known as Kv2.1) and KCNB2 (also known as Kv2.2), and further modulates the delayed rectifier voltage-gated potassium channel activation and deactivation rates of KCNB1 and KCNB2. Voltage-gated potassium (Kv) channels are composed of alpha subunits, which form the actual conductance pore, and cytoplasmic beta subunits, which are auxiliary proteins that associate with alpha subunits to modulate the activity of the Kv channel. KCNS1 is a regulatory alpha subunit that cannot form a functional homo-tetrameric channel. It forms hetero-tetrameric channels (with other functional alpha subunits) through its BTB/POZ domain, also known as tetramerization (T1) domain, which is a versatile protein-protein interaction motif.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1958672652  20 VQLNVGGTRFSTSRQTLMWIPDSFFSSLLS----GRISTLRDETGAI----FIDRDPAAFAPILNFLRTKELD-LRGVSI 90
Cdd:cd18426     1 ININVGGLKRRLSSSTLSKFPDTRLGRLLScdseESILQICDDYDVSakefYFDRNPGLFPYVLHFYQTGKLHiMEELCV 80

                          90       100       110
                  ....*....|....*....|....*....|....*.
gi 1958672652  91 NVLRHEAEFYGITplvrrlllceELERSSCGSVLFH 126
Cdd:cd18426    81 FSFSQEIEYWGIN----------EFFLDSCCSYRYH 106

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain superfamily; Proteins in this superfamily are characterized by the presence of a common protein-protein interaction motif of about 100 amino acids, known as the BTB/POZ domain. Members include transcription factors, oncogenic proteins, ion channel proteins, and potassium channel tetramerization domain (KCTD) proteins. They have been identified in poxviruses and many eukaryotes, and have diverse functions, such as transcriptional regulation, chromatin remodeling, protein degradation and cytoskeletal regulation. Many BTB/POZ proteins contain one or two additional domains, such as kelch repeats, zinc-finger domains, FYVE (Fab1, YOTB, Vac1, and EEA1) fingers, or ankyrin repeats, among others. These special additional domains or interaction partners provide unique characteristics and functions to BTB/POZ proteins. In ion channel proteins and KCTD proteins, the BTB/POZ domain is also called the tetramerization (T1) domain.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1958672652  20 VQLNVGGTRFSTSRQTLMWIPDsFFSSLLSGRISTLRDETgaIFIDR-DPAAFAPILNFLRTKELDLRGVSINVLRHEAE 98
Cdd:cd01165     1 VVLVVEGEKFHVNKELLAQSSE-YFRALFRGGFRESGQAE--INLRDiSPEDFRALLEFLYGGKRDLDASNLLELLEAAN 77

                  ..
gi 1958672652  99 FY 100
Cdd:cd01165    78 FL 79