Protein phosphorylation in pancreatic islets induced by 3-phosphoglycerate and 2-phosphoglycerate

Journal Article · Fri Jun 01 00:00:00 EDT 1990 · Proceedings of the National Academy of Sciences of the United States of America; (United States)

DOI:https://doi.org/10.1073/pnas.87.11.4294· OSTI ID:5393586

Pek, S B; Usami, Masaru; Bilir, N; Fischer-Bovenkerk, C; Ueda, Tetsufumi ^[1]

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1. Univ. of Michigan, Ann Arbor (USA)

The authors have shown previously that 3-phosphoglycerate, which is a glycolytic metabolite of glucose, induces protein phosphorylation in bovine and rat brain and in rat heart, kidney, liver, lung, and whole pancreas. Since glycolytic metabolism of glucose is of paramount importance in insulin release, they considered the possibility that 3-phosphoglycerate may act as a coupling factor, and they searched for evidence for the existence of 3-phosphoglycerate-dependent protein phosphorylation systems in freshly isolated normal rat pancreatic islets. Membrane and cytosol fractions were incubated with ({gamma}-{sup 32}P)ATP and appropriate test substances and were subjected to NaDodSO{sub 4}/PAGE and autoradiography. As little as 0.005 mM 3-phosphoglycerate or 2-phosphoglycerate stimulated the phosphorylation of 65-kDa cytosol protein by as early as 0.25 min. The phosphate bond of the 65-kDa phosphoprotein was sufficiently stable to withstand dialysis; the radioactivity could not be chased out by subsequent exposure to ATP, ADP, 3-phosphoglycerate, or 2,3-bisphosphoglycerate. Moreover, cAMP, cGMP, phorbol 12-myristate 13-acetate, or calcium failed to stimulate the phosphorylation of the 65-kDa protein. Phosphoglycerate-dependent protein phosphorylation in islets may have relevance to stimulation of insulin secretion.

• OSTI ID: 5393586
• Journal Information: Proceedings of the National Academy of Sciences of the United States of America; (United States), Journal Name: Proceedings of the National Academy of Sciences of the United States of America; (United States) Vol. 87:11; ISSN 0027-8424; ISSN PNASA
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
AMP
ANIMALS
ATP
AUTORADIOGRAPHY
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BIOCHEMISTRY
BODY
CARBOHYDRATES
CARCINOGENS
CHEMICAL REACTIONS
CHEMISTRY
DAYS LIVING RADIOISOTOPES
DIGESTIVE SYSTEM
DOSE-RESPONSE RELATIONSHIPS
ELECTROPHORESIS
ENDOCRINE GLANDS
ESTERS
GLANDS
GLYCOLYSIS
HORMONES
INSULIN
ISOTOPES
LIGHT NUCLEI
MAMMALS
METABOLISM
METABOLITES
NUCLEI
NUCLEOTIDES
ODD-ODD NUCLEI
ORGANIC COMPOUNDS
ORGANS
PANCREAS
PEPTIDE HORMONES
PHORBOL ESTERS
PHOSPHORUS 32
PHOSPHORUS ISOTOPES
PHOSPHORYLATION
PROTEINS
RADIOISOTOPES
RATS
RODENTS
SECRETION
VERTEBRATES