title: The Caenorhabditis elegans protein CTBP-1 defines a new group of THAP domain-containing CtBP corepressors.
abstract: The C-terminal binding proteins (CtBPs) play roles in diverse cellular processes including transcriptional regulation, Golgi membrane fission, and synaptic ribbon formation. In the context of transcriptional regulation, they function as corepressors, interacting with promoter-bound transcription factors and recruiting a large protein complex that contains chromatin-modifying enzymes. We recently described the structure of a Thanatos-associated protein (THAP) domain that is found in a new member of the CtBP family, the Caenorhabditis elegans CTBP-1 protein. We have identified additional THAP domain-containing CtBPs in the nematode, echinoderm, and cephalochordate lineages. The distribution of these lineages within the animal kingdom suggests that the ancestral form of the animal CtBPs may have contained a THAP domain that was subsequently lost in the vertebrate and arthropod lineages. We also provide functional data indicating that CTBP-1 represses gene expression and homodimerizes and interacts with PXDLS-containing partner proteins, three key features of the previously characterized animal CtBPs. CTBP-1 is therefore the founding member of a new subgroup within the CtBP corepressor family, the THAP domain-containing CtBPs.
authors.affiliation: School of Molecular and Microbial Biosciences, University of Sydney, Sydney, New South Wales 2006, Australia. hannah@mmb.usyd.edu.au
authors.forename: Hannah R
authors.initials: HR
authors.lastname: Nicholas
authors.forename: Jason A
authors.initials: JA
authors.lastname: Lowry
authors.forename: Tina
authors.initials: T
authors.lastname: Wu
authors.forename: Merlin
authors.initials: M
authors.lastname: Crossley
mesh_terms: D000429:Alcohol Oxidoreductases / Q000737:chemistry / Q000235:genetics; D017398:Alternative Splicing; D000818:Animals; D017173:Caenorhabditis elegans / Q000737:chemistry*; D029742:Caenorhabditis elegans Proteins / Q000737:chemistry* / Q000235:genetics; D018509:DNA, Helminth / Q000235:genetics; D004268:DNA-Binding Proteins / Q000737:chemistry / Q000235:genetics; D019281:Dimerization; D017238:Genes, Helminth; D008957:Models, Genetic; D009154:Mutation; D010802:Phylogeny; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D012097:Repressor Proteins / Q000737:chemistry*; D017422:Sequence Analysis, DNA
chemical_list: C525550:CTBP-1 protein, C elegans; D029742:Caenorhabditis elegans Proteins; D018509:DNA, Helminth; D004268:DNA-Binding Proteins; D012097:Repressor Proteins; D000429:Alcohol Oxidoreductases; C096794:C-terminal binding protein