pubmed:abstractText |
Nuclear receptors activate transcription by recruiting multiple coactivators to the promoters of specific target genes. The functional synergy of the p160 coactivators [steroid receptor coactivator-1, glucocorticoid receptor interacting protein (GRIP1), or the activator for thyroid hormone and retinoid receptors], the histone acetyltransferases cAMP response element binding protein binding protein (CBP) and p300 and the histone methyltransferase coactivator-associated arginine methyltransferase (CARM1) depends on the methyltransferase activity of CARM1. CARM1 methylates histone H3 and other factors including the N-terminal region of p300. Here, we report that CARM1 also methylates Arg-2142 within the C-terminal GRIP1 binding domain (GBD) of p300. In the GBD, both Arg-2088 and Arg-2142 are important for binding GRIP1. Methylation of Arg-2142 inhibits the bimolecular interaction of GRIP1 to p300 in vitro and in vivo. This methylation mark of p300 GBD is removed by peptidyl deiminase 4, thereby enhancing the p300-GRIP1 interaction. These methylation and demethylimination events also alter the conformation and activity of the coactivator complex and regulate estrogen receptor-mediated transcription, and they thus represent unique mechanisms for regulating coactivator complex assembly, conformation, and function.
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pubmed:affiliation |
Department of Pathology, University of Southern California, 2011 Zonal Avenue, HMR 301, Los Angeles, CA 90089, USA.
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