Proteolysis of HCF-1 by Ser/Thr glycosylation-incompetent O-GlcNAc transferase:UDP-GlcNAc complexes.

ABSTRACT: In complex with the cosubstrate UDP-N-acetylglucosamine (UDP-GlcNAc),O-linked-GlcNAc transferase (OGT) catalyzes Ser/ThrO-GlcNAcylation of many cellular proteins and proteolysis of the transcriptional coregulator HCF-1. Such a dual glycosyltransferase-protease activity, which occurs in the same active site, is unprecedented and integrates both reversible and irreversible forms of protein post-translational modification within one enzyme. Although occurring within the same active site, we show here that glycosylation and proteolysis occur through separable mechanisms. OGT consists of tetratricopeptide repeat (TPR) and catalytic domains, which, together with UDP-GlcNAc, are required for both glycosylation and proteolysis. Nevertheless, a specific TPR domain contact with the HCF-1 substrate i

SUBMITTER: Kapuria V 

PROVIDER: S-EPMC4840301 | biostudies-literature | 2016 Apr

REPOSITORIES: biostudies-literature