title: C-terminal binding protein-mediated transcriptional repression is regulated by X-linked inhibitor of apoptosis protein.
abstract: Inhibitors of Apoptosis Proteins (IAPs) are known as the key negative regulators of apoptosis. To explore new functions of IAPs, we sought to identify proteins that interact with Diap1 in insect S2 cells. We found that Diap1 bound to Drosophila C-terminal binding protein (dCtBP), which is a transcriptional co-repressor. CtBP1 also interacted with X-linked inhibitor of apoptosis protein (XIAP) in human cells. CtBPs were ubiquitinated by IAPs and targeted for proteasome-mediated degradation. Finally, the expression of CtBP1 target genes was regulated by XIAP expression. This is the first report to demonstrate that XIAP specifically regulates CtBP1, suggesting that XIAP may play a role in regulating CtBP1-mediated transcriptional repression by regulating the level of CtBP1.
authors.affiliation: Department of Life and Nanopharmaceutical Sciences, Kyung Hee University, Seoul, Republic of Korea.
authors.forename: Ji Sun
authors.initials: JS
authors.lastname: Lee
authors.forename: Sun Kyung
authors.initials: SK
authors.lastname: Lee
authors.forename: Hong-Duk
authors.initials: HD
authors.lastname: Youn
authors.forename: Soon Ji
authors.initials: SJ
authors.lastname: Yoo
mesh_terms: D000429:Alcohol Oxidoreductases / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D017209:Apoptosis; D002460:Cell Line; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism*; D004331:Drosophila melanogaster / Q000235:genetics / Q000378:metabolism*; D005786:Gene Expression Regulation; D057809:HEK293 Cells; D006367:HeLa Cells; D006801:Humans; D051034:Inhibitor of Apoptosis Proteins / Q000235:genetics / Q000378:metabolism*; D046988:Proteasome Endopeptidase Complex / Q000378:metabolism; D014158:Transcription, Genetic; D051636:X-Linked Inhibitor of Apoptosis Protein / Q000235:genetics / Q000378:metabolism*
chemical_list: C111891:DIAP1 protein, Drosophila; D004268:DNA-Binding Proteins; D029721:Drosophila Proteins; D051034:Inhibitor of Apoptosis Proteins; D051636:X-Linked Inhibitor of Apoptosis Protein; D000429:Alcohol Oxidoreductases; C096794:C-terminal binding protein; D046988:Proteasome Endopeptidase Complex