β1 Integrin Ligation Stimulates Tyrosine Phosphorylation of Phospholipase Cγ1 and Elevates Intracellular Ca²⁺in Pancreatic Acinar Cells

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• 作者：Wrenn ; Robert W. ; Creazzo ; Tony L. ; Herman ; Lee E.
• 刊名：Biochemical and Biophysical Research Communications
• 出版年：1996
• 出版时间：September 24, 1996
• 年：1996
• 卷：226
• 期：3
• 页码：876-882
• 全文大小：301 K

文摘

We have recently reported increased tyrosine (TYR) phosphorylation of a number of pancreatic acinar cell proteins following antibody ligation of β1 integrins (Wrenn and Herman,Biochem. Biophys. Res. Commun.208,1995, 978–984). Concurrent with this TYR phosphorylation was a marked activation of protein kinase C (PKC). This led us to investigate phospholipase Cγ1 (PLCγ1), a key enzyme responsible for diacylglycerol generation, as a target for integrin-mediated TYR phosphorylation. Staining with antiphosphotyrosine antibodies revealed increased TYR phosphorylation of immunoprecipitated PLCγ1 prepared from β1 integrin-ligated acinar cells. Subsequent stripping and reprobing of Western blots with polyclonal anti-PLCγ1 was confirmatory. Over this same time period, intracellular [Ca²⁺] increased from <100 nM to 600 nM, further suggesting a functional relevance of integrin-linked phosphorylation as a regulatory mechanism in exocrine pancreas.