Cholecystokinin stimulates heat shock protein 27 phosphorylation in rat pancreas both in vivo and in vitro
| Autor: | John A. Williams, Guy E. Groblewski, Terrence Grady, Neil Mehta, Craig D. Logsdon, H Lambert, J Landry |
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| Rok vydání: | 1997 |
| Předmět: |
Male
endocrine system medicine.medical_specialty animal structures Immunoprecipitation Blotting Western In Vitro Techniques Protein Serine-Threonine Kinases Rats Sprague-Dawley Hsp27 In vivo Heat shock protein Internal medicine medicine Animals Phosphorylation Protein kinase A Pancreas Heat-Shock Proteins Cholecystokinin Hepatology biology Kinase Gastroenterology Intracellular Signaling Peptides and Proteins Phosphoproteins Cell biology Rats Enzyme Activation Endocrinology biology.protein |
| Zdroj: | Gastroenterology. 112(4) |
| ISSN: | 0016-5085 |
| Popis: | BACKGROUND & AIMS: Mammalian heat shock protein 27 (hsp27) is believed to function under normal physiological conditions and during cellular stress. Recent studies indicate a role for hsp27 in regulating actin- cytoskeletal dynamics. In the present study, secretagogue-regulated phosphorylation of hsp27 in rat exocrine pancreas was investigated both in vivo and in isolated acinar cells. METHODS: Western analysis after two-dimensional electrophoresis was used to measure the phosphorylation of hsp27 after treatment of rats or acinar cells with secretagogues. Cholecystokinin-stimulated mitogen-activated protein kinase-activated protein (MAPKAP) kinase 2 activity was measured after immunoprecipitation of the kinase. RESULTS: hsp27 exists as three isoforms in acini: one nonphosphorylated (pI 6.2) and two phosphorylated (pIs 5.9 and 5.7) forms. Infusion of rats with a secretory or supermaximal dose of cerulein produced an acidic shift in hsp27, indicating an increase in its phosphorylation; the higher dose, known to cause pancreatitis, had a twofold greater effect. In isolated acini, increases in hsp27 phosphorylation were evident at 10 pmol/L and maximal at 1 nmol/L cholecystokinin. The hsp27-specific kinase MAPKAP kinase 2 was activated 2.4-fold with 1 nmol/L cholecystokinin treatment. CONCLUSIONS: hsp27 phosphorylation was stimulated by low and high concentrations of cholecystokinin, both in vivo and in vitro. Phosphorylation was potentially mediated via the MAPKAP kinase 2 intracellular signaling pathway. (Gastroenterology 1997 Apr;112(4):1354-61) |
| Databáze: | OpenAIRE |
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