title: Coordinated regulation by Shp2 tyrosine phosphatase of signaling events controlling insulin biosynthesis in pancreatic beta-cells.
abstract: Intracellular signaling by which pancreatic beta-cells synthesize and secrete insulin in control of glucose homeostasis is not fully understood. Here we show that Shp2, a cytoplasmic tyrosine phosphatase possessing 2 SH2 domains, coordinates signaling events required for insulin biosynthesis in beta-cells. Mice with conditional ablation of the Shp2/Ptpn11 gene in the pancreas exhibited defective glucose-stimulated insulin secretion and impaired glucose tolerance. Consistently, siRNA-mediated Shp2-knockdown in rat insulinoma INS-1 832/13 cells resulted in decreased insulin production and secretion despite an increase in cellular ATP. Shp2 modulates the strength of signals flowing through Akt/FoxO1 and Erk pathways, culminating in control of Pdx1 expression and activity on Ins1 and Ins2 promoters, and forced Pdx1 expression rescued insulin production in Shp2-knockdown beta-cells. Therefore, Shp2 acts as a signal coordinator in beta-cells, orchestrating multiple pathways controlling insulin biosynthesis to maintain glucose homeostasis.
authors.affiliation: Burnham Institute for Medical Research, 10901 North Torrey Pines Road, La Jolla, CA 92037, USA.
authors.forename: Sharon S
authors.initials: SS
authors.lastname: Zhang
authors.forename: Ergeng
authors.initials: E
authors.lastname: Hao
authors.forename: Jianxiu
authors.initials: J
authors.lastname: Yu
authors.forename: Wen
authors.initials: W
authors.lastname: Liu
authors.forename: Jing
authors.initials: J
authors.lastname: Wang
authors.forename: Fred
authors.initials: F
authors.lastname: Levine
authors.forename: Gen-Sheng
authors.initials: GS
authors.lastname: Feng
mesh_terms: D000818:Animals; D002460:Cell Line; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism; D000071161:Forkhead Box Protein O1; D051858:Forkhead Transcription Factors / Q000378:metabolism; D005947:Glucose / Q000378:metabolism / Q000494:pharmacology; D018398:Homeodomain Proteins / Q000096:biosynthesis / Q000235:genetics; D007328:Insulin / Q000096:biosynthesis* / Q000378:metabolism; D000078790:Insulin Secretion; D050417:Insulin-Secreting Cells / Q000187:drug effects / Q000201:enzymology* / Q000378:metabolism; D051379:Mice; D018345:Mice, Knockout; D054592:Protein Tyrosine Phosphatase, Non-Receptor Type 11 / Q000235:genetics / Q000378:metabolism*; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D015534:Trans-Activators / Q000096:biosynthesis / Q000235:genetics
chemical_list: D000071161:Forkhead Box Protein O1; D051858:Forkhead Transcription Factors; C467200:Foxo1 protein, mouse; D018398:Homeodomain Proteins; D007328:Insulin; D015534:Trans-Activators; C084010:pancreatic and duodenal homeobox 1 protein; D051057:Proto-Oncogene Proteins c-akt; D048049:Extracellular Signal-Regulated MAP Kinases; D054592:Protein Tyrosine Phosphatase, Non-Receptor Type 11; C516725:Ptpn11 protein, mouse; D005947:Glucose