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 10863937    30 VQLNVGGSLYYTTVRALTR-HDTMLKAMFSGRMEVLTDKEGWILIDRCGKHFGTILNYLRDDtITLPQNRQ-EIKELMAE 107
Cdd:pfam02214   1 VKLNVGGTRFETLKSTLTRfPDTRLGRLLELECDDYDDDTNEYFFDRSPKHFETILNFYRTG-GKLHRPEEvCLDEFLEE 79

                  ....*....
gi 10863937   108 AKYYLIQGL 116
Cdd:pfam02214  80 AEFYGLDEL 88

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium channel tetramerization domain-containing proteins, KCTD10 (BACURD3), KCTD13 (BACURD1), and TNFAIP1 (BACURD2); This subfamily of KCTD proteins, also called the BTB/POZ domain-containing adapter for CUL3-mediated RhoA degradation protein (BACURD) subfamily, includes KCTD10 (BACURD3), KCTD13 (BACURD1), and TNFAIP1 (BACURD2). KCTD10 is a BTB/POZ domain-containing protein that interacts with proliferating cell nuclear antigen (PCNA) and polymerase delta, and participates in DNA repair, DNA replication, and cell-cycle control. Its down-regulation could inhibit cell proliferation. KCTD10 also plays crucial roles in embryonic angiogenesis and heart development in mammals by negatively regulating the Notch signaling pathway. KCTD13 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. TNFAIP1, also called protein B12, is a BTB/POZ domain-containing protein that is involved in DNA replication, DNA damage repair, 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. KCTD10 and KCTD13 BTB domains 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 10863937  30 VQLNVGGSLYYTTVRALTRHDTMLKAMFSGRMEVLTDKEGWILIDRCGKHFGTILNYLRDDTITLPQNRQEIKELMAEAK 109
Cdd:cd18369   1 VKLNVGGSLHYTTIGTLTKQDTMLRAMFSGRMEVLTDSEGWILIDRCGKHFGTILNYLRDGSVPLPESRRELAELLAEAK 80

                        90
                ....*....|.
gi 10863937 110 YYLIQGLVNMC 120
Cdd:cd18369  81 YYLVQGLVEQC 91

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium channel tetramerization domain-containing protein 10 (KCTD10); KCTD10, also called BTB/POZ domain-containing adapter for CUL3-mediated RhoA degradation protein 3 (BACURD3), is a BTB/POZ domain-containing protein that interacts with proliferating cell nuclear antigen (PCNA) and polymerase delta, and participates in DNA repair, DNA replication, and cell-cycle control. Its down-regulation could inhibit cell proliferation. KCTD10 also plays crucial roles in embryonic angiogenesis and heart development in mammals by negatively regulating the Notch signaling pathway. Furthermore, KCTD10 may function as a substrate-specific adaptor of a BCR (BTB-CUL3-RBX1) E3 ubiquitin-protein ligase complex, which mediates the ubiquitination of target proteins, leading to their degradation by the proteasome. 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 KCTD10 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 10863937  22 GGGLGNKYVQLNVGGSLYYTTVRALTRHDTMLKAMFSGRMEVLTDKEGWILIDRCGKHFGTILNYLRDDTITLPQNRQEI 101
Cdd:cd18399   1 GTSPSSKYVKLNVGGALYYTTMQTLTKQDTMLKAMFSGRMEVLTDSEGWILIDRCGKHFGTILNYLRDGAVPLPESRREI 80

                        90       100       110
                ....*....|....*....|....*....|.
gi 10863937 102 KELMAEAKYYLIQGLVNMCQSALQdKKDSYQ 132
Cdd:cd18399  81 EELLAEAKYYLVQGLVEECQAALQ-NKDTYE 110

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium channel tetramerization domain-containing proteins; The potassium channel tetramerization domain (KCTD) family proteins contain the BTB/POZ domain, also known as tetramerization (T1) domain, which is a versatile protein-protein interaction motif that facilitates homodimerization or heterodimerization. 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. Some others show Cullin-independent functions including binding and regulation of GABA (gamma-aminobutyric acid) receptors (KCTD8, KCTD12 and KCTD16) and inhibition of AP-2 function (KCTD15). 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 10863937  30 VQLNVGGSLYYTTVRALTRH-DTMLKAMFSGRMEVLTDKEGWILIDRCGKHFGTILNYLRDDTITLPQNRQEIKELMAEA 108
Cdd:cd18316   1 VKLNVGGTLFTTSRSTLLKDpDSLLAALFSGRWPLPRDEDGSIFIDRDPELFRHILNFLRTGKLPLPSDFVELEELLAEA 80

                ...
gi 10863937 109 KYY 111
Cdd:cd18316  81 EFY 83

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium channel tetramerization domain-containing proteins, KCTD6, KCTD21 and similar proteins; KCTD6, also called KCASH3 (KCTD containing, Cullin3 adaptor, suppressor of Hedgehog 3), is a substrate-specific adaptor of cullin-3, effectively regulating protein levels of the muscle small ankyrin-1 isoform 5 (sAnk1.5). KCTD21, also called KCASH2, 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 10863937  30 VQLNVGGSLYYTTVRALTRH-DTMLKAMFSGRMEVLTDKEGWILIDRCGKHFGTILNYLRDDTITLPQNRQEIKELMAEA 108
Cdd:cd18365   3 VNLNVGGVHYTTTLATLTRFpDSMLGAMFSGSMPTTRDDQGNYFIDRDGTLFRYILNFLRSSQLSLPEDFKEYDLLLREA 82

                ....*....
gi 10863937 109 KYYLIQGLV 117
Cdd:cd18365  83 DFYQIEPLI 91

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 10863937  30 VQLNVGGSLYYTTVRALTRH-DTMLKAMFSGRMEVLTDKEGWILIDRCGKHFGTILNYLRDDTITLPQNRQEIKELMAEA 108
Cdd:cd18395   3 ITLNVGGKLYTTSLATLTRYpDSMLGAMFSGKFPTKKDSQGNCFIDRDGKIFRYILNFLRTSHLDLPEDFQEMGLLKREA 82

                        90       100
                ....*....|....*....|
gi 10863937 109 KYYLIQGLVnmcqSALQDKK 128
Cdd:cd18395  83 DFYQIQPLI----EALQEKE 98

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 10863937  30 VQLNVGGSLYYTTVRALTRH-DTMLKAMFSG--RMEVLTDKEGWILIDRCGKHFGTILNYLRDDTITLPQNRQEIKELMA 106
Cdd:cd18367   5 VELNVGGQVYTTSLSTLIKDpDSLLGRMFSGknRQELARDSKGRYFLDRDGVLFRYILDYLRNQKLVLPENFPERERLKR 84

                        90
                ....*....|....*.
gi 10863937 107 EAKYYLIQGLVNMCQS 122
Cdd:cd18367  85 EAEYFQLPELVKALRA 100

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium channel tetramerization domain-containing protein KCTD11; KCTD11 may function as an antagonist of the Hedgehog pathway of cell proliferation and differentiation by affecting the nuclear transfer of transcription factor GLI1, thus maintaining cerebellar granule cells in the undifferentiated state. It is a probable substrate-specific adapter for a BCR (BTB-CUL3-RBX1) E3 ubiquitin-protein ligase complex towards HDAC1. It contains a BTB/POZ domain; in some cases the domain may be truncated. 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. Variants of the human/mouse KCTD11 appear to contain truncated BTB/POZ domains.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 10863937  30 VQLNVGGSLYYTTVRALTRH-DTMLKAMFSGRMEVL----TDKEGWILIDRCGKHFGTILNYLRDDTITLPQNRQEIKEL 104
Cdd:cd18370   1 VTLNVGGTLYSTTLETLTRFpDSMLGAMFRAGTPIPpnlnMQGGGHYFIDRDGKAFRHILNFLRLGRLDLPRGYGETALL 80

                ....*..
gi 10863937 105 MAEAKYY 111
Cdd:cd18370  81 RAEADFY 87

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium channel tetramerization domain-containing proteins, KCTD1 and KCTD15; This subfamily of KCTD proteins includes KCTD1 and KCTD15. 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. It also functions as a novel inhibitor of the Wnt signaling pathway. Mutations in KCTD1 cause scalp-ear-nipple (SEN) syndrome. 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 form pentamers.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 10863937  30 VQLNVGGSLYYTTVRALTRH-DTMLKAMFSGRMEVLTD--KEGWiLIDRCGKHFGTILNYLRDDTITLPQNRQEIKELMA 106
Cdd:cd18361   1 VHIDVGGHIYTSSLETLTKYpESRLGKLFNGSIPIVLDslKQHY-FIDRDGKMFRHILNFLRTSKLLLPDDFTEFDLLYE 79

                        90
                ....*....|..
gi 10863937 107 EAKYYLIQGLVN 118
Cdd:cd18361  80 EARYYELQPMVK 91

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium channel tetramerization domain-containing protein 4 (KCTD4); KCTD4 is a BTB/POZ domain-containing protein with an 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 10863937  30 VQLNVGGSLYYTTVRALTRH-DTMLKAMFSGRMEVLTDKEGWILIDRCGKHFGTILNYLRDDTITLPQNRQEIKELMAEA 108
Cdd:cd18364   2 VTLNVGGYLYITQRQTLTKYpDSFLEGMVNGKIQCTVDADGNYFIDRDGLLFRHVLNFLRNGELLLPEGFQENQLLALEA 81

                ...
gi 10863937 109 KYY 111
Cdd:cd18364  82 DFY 84

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium channel tetramerization domain-containing protein 16 (KCTD16); KCTD16 is a BTB/POZ domain-containing protein that is an auxiliary subunit of GABAB receptors associated with mood disorders. It 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 10863937  30 VQLNVGGSLYYTTVRALTR-HDTMLKAMFSGRMEVLTD----KEGWILIDRCGKHFGTILNYLRDDTITLPQNRQEIKEL 104
Cdd:cd18398   5 VELNVGGQVYFTRHATLVSiPHSLLWKMFSPKRDTANDlakdSKGRFFIDRDGFLFRYILDYLRDRQVVLPDHFPEKGRL 84

                        90
                ....*....|....*
gi 10863937 105 MAEAKYYLIQGLVNM 119
Cdd:cd18398  85 KREAEYFQLPDLVKL 99

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 10863937  30 VQLNVGGSLYYTTVRALTR-HDTMLKAMFSGRMEVLTDKEGWILIDRCGKHFGTILNYLRDDtITLPQNRQEIKELMAEA 108
Cdd:cd18372   3 LRLNVGGCIYTARRESLCRfKDSMLSSMFSGRFPLKLDESGACVIDRDGRLFKYLLDYLHGE-LQIPEDEQTRLALQEEA 81

                ....*
gi 10863937 109 KYYLI 113
Cdd:cd18372  82 DYFGI 86

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 10863937  30 VQLNVGGSLYYTTVRALT-RHDTMLKAMFSGRMEVLTDKEGWILIDRCGKHFGTILNYLRddTITLPQNRQEIKELMAEA 108
Cdd:cd18393   4 IHLNVGGKRFSTSRQTLTwIPDSFFSSLLSGRISTLKDETGAIFIDRDPTVFAPILNFLR--TKELDPRGIHVSLLLHEA 81

                        90
                ....*....|...
gi 10863937 109 KYYLIQGLVNMCQ 121
Cdd:cd18393  82 QFYGITPLVRRLQ 94

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 10863937  27 NKYVQLNVGGSLYYTTVRALTRH-DTMLKAMFSGRMEVLTDK-EGWILIDRCGKHFGTILNYLRDDTITLPQNRQEIKEL 104
Cdd:cd18388   1 NAPVHIDVGGHMYTSSLATLTKYpDSRISRLFNGTEPIVLDSlKQHYFIDRDGEIFRYILSFLRTSKLLLPEDFKDFNLL 80

                        90
                ....*....|...
gi 10863937 105 MAEAKYYLIQGLV 117
Cdd:cd18388  81 YEEAKYYQLQPMV 93

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 10863937  28 KYVQLNVGGSLYYTTVRALTRH-DTMLKAMFSGRMEVLTDKE--GWILIDRCGKHFGTILNYLRDDTITLPQNRQEiKEL 104
Cdd:cd18389   1 KWVRLNVGGTYFVSTKQTLCRDpKSFLYRLCQEDPDLDSDKDetGAYLIDRDPTYFGPILNYLRHGKLIINKELAE-EGV 79

                        90       100
                ....*....|....*....|....*
gi 10863937 105 MAEAKYYLIQGLVNMCQSALQDKKD 129
Cdd:cd18389  80 LEEAEFYNIASLVRLVKERIRDNEN 104

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in voltage-gated potassium (Kv) channels and potassium channel tetramerization domain-containing (KCTD) proteins; This family includes two protein groups: voltage-gated potassium (Kv) channels and potassium channel tetramerization domain-containing (KCTD) proteins. Kv channels are membrane proteins with fundamental physiological roles. They are responsible for a variety of electrical phenomena, such as the repolarization of the action potential, spike frequency adaptation, synaptic repolarization, and smooth muscle contraction. 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. All family members contain the 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 10863937  30 VQLNVGGSLYYTTVRALTRH-DTMLKAMFsGRMEVLTDKE--GWILIDRCGKHFGTILNYLRDDTITLPQNrQEIKELMA 106
Cdd:cd18187   1 VVLNVSGTRFVTNRQTLTRHpDTLLGRMF-KPGREFTFPNetGEYFIDRDPTVFRTILNYYRTGKLNCPDG-ISIPDLRE 78

                ....*
gi 10863937 107 EAKYY 111
Cdd:cd18187  79 ECDFY 83

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 10863937  29 YVQLNVGGSLYYTTVRALTRH-DTMLKAMFSGRMEVLTDKE--GWILIDRCGKHFGTILNYLRDDTITLPQNRQEiKELM 105
Cdd:cd18362   1 WVKLNVGGTYFLTTRTTLCRDpKSFLCRLCQEDPDLPSDKDetGAYLIDRDPTYFGPILNYLRHGKLIIDKDLAE-EGVL 79

                ....*.
gi 10863937 106 AEAKYY 111
Cdd:cd18362  80 EEAEFY 85