A non-receptor-type protein phosphotyrosine phosphatase is enriched in secretory vesicles of glucagon - and pancreatic polypeptide - secreting cells of the endocrine pancreas.
The secretory vesicles of some cells of the islets of Langerhans of the pancreas contain high amounts of immunoreactive tyrosine phosphatase of the PTP1B/TCPTP subfamily. The cells are located in the peripheral parts of the islets and were identified as glucagon- and pancreatic polypeptide-forming cells. The tyrosine phosphatase is also enriched in some of the somatostatin-producing cells but is not elevated either in insulin-producing B-cells or in the exocrine pancreas. Virtually the same patterns were found in pancretic tissues of rats, guinea pigs, pigs, and mice. High levels of detergent-soluble tyrosine phosphatase were measured in the particular fraction of pancreatic islets with a substrate preferred by PTP1B/TCPTP-type protein tyrosine phosphatases.
Wimmer
M
M
Institute of Anatomy and Cell Biology, Justus-Liebig-University Giessen, Germany. monika.wimmer@anatomie.med.uni-giessen.de
Tag
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Hofer
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HW
D000818:Animals; D005934:Glucagon / Q000032:analysis* / Q000378:metabolism; D006168:Guinea Pigs; D006801:Humans; D007150:Immunohistochemistry; D007515:Islets of Langerhans / Q000166:cytology / Q000201:enzymology* / Q000648:ultrastructure; D051379:Mice; D010191:Pancreatic Polypeptide / Q000032:analysis* / Q000378:metabolism; D017027:Protein Tyrosine Phosphatases / Q000032:analysis*; D051381:Rats; D013552:Swine
D010191:Pancreatic Polypeptide; D005934:Glucagon; D017027:Protein Tyrosine Phosphatases