title: The Ikaros family protein Eos associates with C-terminal-binding protein corepressors.
abstract: Eos is a zinc finger transcription factor of the Ikaros family. It binds typical GGGAA Ikaros recognition sites in DNA and functions as a transcriptional repressor. Here we show that Eos associates with the corepressor C-terminal-binding protein (CtBP). CtBP has previously been shown to bind Pro-X-Asp-Leu-Ser (PXDLS) motifs in several DNA-binding proteins. We note that Eos contains a related motif PEDLA, and we demonstrate that CtBP can bind this site weakly but that it also contacts additional regions of Eos. Consistent with this finding, mutation of the PEDLA motif does not negate CtBP binding or CtBP-mediated repression by Eos. CtBP has previously been shown to bind to a PXDLS-type motif in Ikaros, and we show that another Ikaros-related protein TRPS1 also contains a PXDLS CtBP contact motif within its repression domain. We conclude that several Ikaros family proteins utilize CtBP corepressors to inhibit gene expression.
authors.affiliation: Department of Biochemistry, G08, University of Sydney, NSW, Australia.
authors.forename: José
authors.initials: J
authors.lastname: Perdomo
authors.forename: Merlin
authors.initials: M
authors.lastname: Crossley
mesh_terms: D016475:3T3 Cells; D000818:Animals; D019556:COS Cells; D002352:Carrier Proteins / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000378:metabolism; D051379:Mice; D009363:Neoplasm Proteins; D009419:Nerve Tissue Proteins / Q000378:metabolism*; D009687:Nuclear Proteins / Q000378:metabolism; D011485:Protein Binding; D012097:Repressor Proteins / Q000737:chemistry / Q000378:metabolism*; D014157:Transcription Factors; D020798:Two-Hybrid System Techniques; D016335:Zinc Fingers
chemical_list: D002352:Carrier Proteins; D004268:DNA-Binding Proteins; D009363:Neoplasm Proteins; D009419:Nerve Tissue Proteins; D009687:Nuclear Proteins; D012097:Repressor Proteins; C108387:TRPS1 protein, human; D014157:Transcription Factors; C118760:Zfpn1a4 protein, mouse