PARTNERSHIP OPPORTUNITIES
Substrate-recognition component of the PNUTS-PP1 protein phosphatase complex, a protein phosphatase 1 (PP1) complex that promotes RNA polymerase II transcription pause-release, allowing transcription elongation (PubMed:39603239, PubMed:39603240). Promoter-proximal pausing by RNA polymerase II is a transcription halt following transcription initiation but prior to elongation, which acts as a checkpoint to control that transcripts are favorably configured for transcriptional elongation (PubMed:39603239, PubMed:39603240). The PNUTS-PP1 complex mediates the release of RNA polymerase II from promoter-proximal region of genes by catalyzing dephosphorylation of proteins involved in transcription, such as AFF4, CDK9, MEPCE, INTS12, NCBP1, POLR2M/GDOWN1 and SUPT6H (PubMed:39603239, PubMed:39603240). The PNUTS-PP1 complex also regulates RNA polymerase II transcription termination by mediating dephosphorylation of SUPT5H in termination zones downstream of poly(A) sites, thereby promoting deceleration of RNA polymerase II transcription (PubMed:31677974). PNUTS-PP1 complex is also involved in the response to replication stress by mediating dephosphorylation of POLR2A at ‘Ser-5’ of the CTD, promoting RNA polymerase II degradation (PubMed:33264625). The PNUTS-PP1 complex also plays a role in the control of chromatin structure and cell cycle progression during the transition from mitosis into interphase (By similarity). PNUTS-PP1 complex mediates dephosphorylation of MYC, promoting MYC stability by preventing MYC ubiquitination by the SCF(FBXW7) complex (PubMed:30158517). In addition to acts as a substrate-recognition component, PPP1R10/PNUTS also acts as a nuclear targeting subunit for the PNUTS-PP1 complex (PubMed:9450550). In some context, PPP1R10/PNUTS also acts as an inhibitor of protein phosphatase 1 (PP1) activity by preventing access to substrates, such as RB (PubMed:18360108).
