Phosphorylation of p300 at Serine 89 by Protein Kinase C

• Published in: The Journal of biological chemistry Vol. 275; no. 52; pp. 40946 - 40951
• Main Authors: Yuan, L. Wuchao, Gambee, Jay E.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 29-12-2000; American Society for Biochemistry and Molecular Biology
• Subjects: HeLa Cells; Humans; Nuclear Proteins - metabolism; Phosphorylation; Protein Kinase C - physiology; Serine - metabolism; Trans-Activators - metabolism; Transcriptional Activation
• ISSN: 0021-9258; 1083-351X
• DOI: 10.1074/jbc.M007832200

CREB-binding protein (CBP)/p300 plays an important role in the connection of many different signal transduction pathways and the promotion of certain differentiation and proliferation processes. This role depends upon the ability of CBP/p300 to serve as coactivator for transcription factors. It has been suggested that CBP/p300 is regulated by phosphorylation, but the nature of the phosphorylation, the responsible kinase in vivo, and its physiological significance are still unclear. Here, we demonstrate the first identification of an in vivo phosphorylation site, conserved serine 89, in p300. Signal-dependent protein kinase C is able to phosphorylate serine 89 and mediates this phosphorylation event in vivo. Different from other phosphorylation observed so far in CBP/p300, this serine 89-specific phosphorylation represses the transcriptional activity of p300. This phosphorylation-mediated regulation of p300 function represents a previously unrecognized signal transduction pathway for protein kinase C to regulate cell growth and differentiation.