Chemical Tools To Decipher Regulation of Phosphatases by Proline Isomerization on Eukaryotic RNA Polymerase II.

ABSTRACT: Proline isomerization greatly impacts biological signaling but is subtle and difficult to detect in proteins. We characterize this poorly understood regulatory mechanism for RNA polymerase II carboxyl terminal domain (CTD) phosphorylation state using novel, direct, and quantitative chemical tools. We determine the proline isomeric preference of three CTD phosphatases: Ssu72 as cis-proline specific, Scp1 and Fcp1 as strongly trans-preferred. Due to this inherent characteristic, these phosphatases respond differently to enzymes that catalyze the isomerization of proline, like Ess1/Pin1. We demonstrate that this selective regulation of RNA polymerase II phosphorylation state exists within human cells, consistent with in vitro assays. These results support a model in which, instead of a global

SUBMITTER: Mayfield JE 

PROVIDER: S-EPMC4788383 | biostudies-literature | 2015 Oct

REPOSITORIES: biostudies-literature