| Structural highlights
Function
[CBP_MOUSE] Acetylates histones, giving a specific tag for transcriptional activation. Also acetylates non-histone proteins, like NCOA3 and FOXO1. Binds specifically to phosphorylated CREB and enhances its transcriptional activity toward cAMP-responsive genes. Acts as a coactivator of ALX1 in the presence of EP300 (By similarity).[1] [2] [3] [4]
Publication Abstract from PubMed
Forkhead box class O 3a (FOXO3a) is a transcription factor and tumor suppressor linked to longevity that determines cell fate through activating transcription of cell differentiation, survival, and apoptotic genes. Recruitment of the coactivator CBP/p300 is a crucial step in transcription, and we revealed that in addition to conserved region 3 (CR3) of FOXO3a, the C-terminal segment of CR2 (CR2C) binds CBP/p300 and contributes to transcriptional activity. CR2C and CR3 of FOXO3a interact with the KIX domain of CBP/p300 at both "MLL" and "c-Myb" binding sites simultaneously. A FOXO3a CR2C-CR3 peptide in complex with KIX exists in equilibrium between two equally populated conformational states, one of which has CR2C bound to the MLL site and CR3 bound to the c-Myb site, whereas in the other, CR2C and CR3 bind the c-Myb and MLL sites, respectively. This promiscuous interaction between FOXO3a and CBP/p300 is further supported by additional binding sites on CBP/p300, namely, the TAZ1 and TAZ2 domains. In functional studies, our structure-guided mutagenesis showed that both CR2C and CR3 are involved in the activation of certain endogenous FOXO3a target genes. Further, phosphorylation of S626, a known AMP-dependent protein kinase target in CR3, increased affinity for CBP/p300 and the phosphomimetic mutation enhanced transactivation of luciferase. These findings underscore the significance of promiscuous multivalent interactions and posttranslational modification in the recruitment of transcriptional coactivators, which may allow transcription factors to adapt to various gene-specific genomic and chromatin structures and respond to cell signals.
Structures of KIX domain of CBP in complex with two FOXO3a transactivation domains reveal promiscuity and plasticity in coactivator recruitment.,Wang F, Marshall CB, Yamamoto K, Li GY, Gasmi-Seabrook GM, Okada H, Mak TW, Ikura M Proc Natl Acad Sci U S A. 2012 Apr 17;109(16):6078-83. Epub 2012 Apr 2. PMID:22474372[5]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Hung HL, Lau J, Kim AY, Weiss MJ, Blobel GA. CREB-Binding protein acetylates hematopoietic transcription factor GATA-1 at functionally important sites. Mol Cell Biol. 1999 May;19(5):3496-505. PMID:10207073
- ↑ Xu W, Chen H, Du K, Asahara H, Tini M, Emerson BM, Montminy M, Evans RM. A transcriptional switch mediated by cofactor methylation. Science. 2001 Dec 21;294(5551):2507-11. Epub 2001 Nov 8. PMID:11701890 doi:10.1126/science.1065961
- ↑ Daitoku H, Hatta M, Matsuzaki H, Aratani S, Ohshima T, Miyagishi M, Nakajima T, Fukamizu A. Silent information regulator 2 potentiates Foxo1-mediated transcription through its deacetylase activity. Proc Natl Acad Sci U S A. 2004 Jul 6;101(27):10042-7. Epub 2004 Jun 25. PMID:15220471 doi:10.1073/pnas.0400593101
- ↑ Kuo HY, Chang CC, Jeng JC, Hu HM, Lin DY, Maul GG, Kwok RP, Shih HM. SUMO modification negatively modulates the transcriptional activity of CREB-binding protein via the recruitment of Daxx. Proc Natl Acad Sci U S A. 2005 Nov 22;102(47):16973-8. Epub 2005 Nov 15. PMID:16287980 doi:10.1073/pnas.0504460102
- ↑ Wang F, Marshall CB, Yamamoto K, Li GY, Gasmi-Seabrook GM, Okada H, Mak TW, Ikura M. Structures of KIX domain of CBP in complex with two FOXO3a transactivation domains reveal promiscuity and plasticity in coactivator recruitment. Proc Natl Acad Sci U S A. 2012 Apr 17;109(16):6078-83. Epub 2012 Apr 2. PMID:22474372 doi:10.1073/pnas.1119073109
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