S-phase PARylation of microprotein RSMC enhances the function of Sororin in sister chromatid cohesion

ABSTRACT: Sororin is essential for establishing sister chromatid cohesion concurrently with DNA replication in metazoans. Although acetylation of the cohesin subunit SMC3 by ESCO1/2 is necessary for Sororin recruitment, it is by itself not sufficient. Here we demonstrate that DNA replication-coupled Poly(ADP-Ribose) Polymerase (PARP) activity is an additional prerequisite in human cells. During normal S-phase, PARP1 PARylates a microprotein encoded by the alternative ORF C11ORF98, which we designate RSMC (28S rRNA/ribosome and Sororin micro-cofactor). This PARylation strengthens the interaction of RSMC with Sororin, enhancing both chromatin recruitment and anti-Wapl activity of Sororin in concert with SMC3 acetylation. Notably, overexpression of RSMC is able to rescue cohesion defects induced by the

SUBMITTER: Meiqian Jiang 

PROVIDER: S-SCDT-10_1038-S44318-025-00641-8 | biostudies-other |

REPOSITORIES: biostudies-other