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Updated: Jun 22, 2026

Oligopeptide Competition Assay for Phosphorylation Site Determination
Published on: May 18, 2017
Identification of calcineurin regulated phosphorylation sites on CRHSP-24
SaeHong Lee1, Matthew J Wishart, John A Williams
1Department of Molecular and Integrative Physiology, University of Michigan Medical School, Ann Arbor, MI 48109, USA.
Abstract:
CRHSP-24 is a prominently regulated phosphoprotein in pancreatic acinar cells where it is the major substrate for the serine/threonine protein phosphatase, calcineurin, in response to secretagogues. We now identify the four regulated sites of CRHSP-24 phosphorylation as serines 30, 32, 41, and 52 and show that Ser(30) and Ser(32) are directly dephosphorylated by calcineurin. Coordinate phosphorylation/dephosphorylation of these four serines explains the multiple phosphorylated isoforms of CRHSP-24 present in acinar cells and provides a molecular framework to study CRHSP-24 regulation by secretagogues and growth factor-induced kinases and phosphatases in vivo.
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