title: Characterization and expression of a human KCTD1 gene containing the BTB domain, which mediates transcriptional repression and homomeric interactions.
abstract: We identified potassium channel tetramerization domain-containing 1 (KCTD1) gene in a human brain cDNA library. Here, we report that the KCTD1 gene contains seven exons, encoding 257 amino acid residues with a predicted molecular mass of 29.4 kDa. Sequence alignments showed KCTD1 protein contains an N-terminal broad-complex, tramtrack, and bric-a-brac (BTB) domain. Northern blot analysis revealed that KCTD1 is expressed in the mammary gland, kidney, brain, and ovary compared to other tissues. Further, the subcellular localization results showed that KCTD1 is localized in the nuclei of HeLa and HBL100 cells. Reporter gene assays in HEK293FT and NIH3T3 cells further indicated that KCTD1 acts as a potent transcriptional repressor and inhibits the transcriptional activity via its BTB domain, though KCTD1 transcriptional repression is unaffected by the HDAC inhibitors, trichostatin A, and sodium butyrate. Finally, we found that the BTB domain of KCTD1 mediates homomeric protein-protein interactions by co-immunoprecipitation and GST pull-down assays. These data present the first characterization of human KCTD1 and suggest that KCTD1 is a nuclear protein that functions as a transcriptional repressor and mediates protein-protein interactions through a BTB domain.
authors: Model Animal Research Center and State Key Laboratory of Pharmaceutical Biotechnology, Nanjing University, Nanjing, China.
authors: Xiao-Feng
authors: XF
authors: Ding
authors: Chang
authors: C
authors: Luo
authors: Kai-Qun
authors: KQ
authors: Ren
authors: Jing
authors: J
authors: Zhang
authors: Jian-Lin
authors: JL
authors: Zhou
authors: Xiang
authors: X
authors: Hu
authors: Ru-Shi
authors: RS
authors: Liu
authors: Yan
authors: Y
authors: Wang
authors: Xiang
authors: X
authors: Gao
authors: Jian
authors: J
authors: Zhang
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D015152:Blotting, Northern; D015153:Blotting, Western; D002467:Cell Nucleus / Q000378:metabolism; D002478:Cells, Cultured; D003001:Cloning, Molecular; D056970:Co-Repressor Proteins; D005091:Exons / Q000235:genetics; D005455:Fluorescent Antibody Technique; D006801:Humans; D047468:Immunoprecipitation; D008297:Male; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000235:genetics* / Q000276:immunology / Q000378:metabolism; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D011817:Rabbits; D012097:Repressor Proteins / Q000235:genetics* / Q000276:immunology / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017386:Sequence Homology, Amino Acid; D014158:Transcription, Genetic
chemical_list: D056970:Co-Repressor Proteins; C529677:KCTD1 protein, human; D009687:Nuclear Proteins; D012333:RNA, Messenger; D012097:Repressor Proteins