Histone acetyltransferase activity of CBP is controlled by cycle-dependent kinases and oncoprotein E1A

TLDR: CBP, like Rb, is controlled by phosphorylation at the G1/S boundary, increasing its histone acetyltransferase activity, which is mimicked by E1A.

Abstract: Transforming viral proteins such as E1A force cells through the restriction point of the cell cycle into S phase by forming complexes with two cellular proteins1,2,3: the retinoblastoma protein (Rb)4, a transcriptional co-repressor5, and CBP/p300 (ref. 6), a transcriptional co-activator7,8,9. These two proteins locally influence chromatin structure: Rb recruits a histone deacetylase10,11,12, whereas CBP is a histone acetyltransferase13,14. Progression through the restriction point is triggered by phosphorylation of Rb, leading to disruption of Rb-associated repressive complexes and allowing the activation of S-phase genes15. Here we show that CBP, like Rb, is controlled by phosphorylation at the G1/S boundary, increasing its histone acetyltransferase activity. This enzymatic activation is mimicked by E1A.