SUMOylation of the transcriptional co-repressor KAP1 is regulated by the serine and threonine phosphatase PP1.

ABSTRACT: Krüppel-associated box (KRAB) domain-associated protein 1 [KAP1, also known as transcription intermediary factor-1beta (TIF1beta)] is a ubiquitous transcriptional co-repressor that is susceptible to phosphorylation at Ser(824) by ataxia-telangiectasia mutated (ATM) and to modification by small ubiquitin-like modifying (SUMO) proteins. Here, we found that, whereas the protein phosphatase 1alpha isoform (PP1alpha) directly interacted with KAP1 under basal conditions, PP1beta interacted with KAP1 only in response to genotoxic stress. Changes in the abundance of PP1alpha or PP1beta had differential effects on the phosphorylation and SUMOylation states of KAP1 under basal conditions and in response to DNA double-strand breaks (DSBs). Chromatin immunoprecipitation and re-immunoprecipitation expe

SUBMITTER: Li X 

PROVIDER: S-EPMC3302164 | biostudies-literature | 2010 Apr

REPOSITORIES: biostudies-literature