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

Abstract

We 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, we considered the possibility that 3-phosphoglycerate may act as a coupling factor, and we searched for evidence for the existence of 3-phosphoglycerate-dependent protein phosphorylation systems in freshly isolated normal rat pancreatic islets.

Regulation by glucose and calcium of the carboxylmethylation of the catalytic subunit of protein phosphatase 2A in insulin-secreting INS-1 cells

“…Several original studies by us (20) and those of others (3,11,16,17,25,29,30,35,37,38,47) have indicated stimulation by insulin secretagogues of phosphorylation of ␤-cell proteins, implying that such an event is critical for insulin secretion. As indicated above, net phosphorylation status of a given protein is determined by the efficiency and concerted actions of protein kinases as well as protein phosphatases.…”

Rapid ATP‐Dependent Priming of Secretory Granules Precedes Ca2+ ‐Induced Exocytosis in Mouse Pancreatic B‐Cells

“…This is suggested by the recent demonstration that the Krebs cycle intermediate succinate is able to stimulate insulin secretion from permeabilized B‐cells in which the ATP‐concentration was clamped (Maechler, Kennedy & Wollheim, 1996). In this context it is likewise of interest that the glycolytic intermediate B‐phosphoglycerate stimulates insulin secretion and phosphorylates a 65 kDa protein (Pek, Usami, Bilir, Fisher‐Bovenkerk & Ueda, 1990).…”

Phosphocreatine-dependent protein phosphorylation in rat skeletal muscle

“…There have been a number of previous reports of cytosolic proteins whose phosphorylation state can be modulated by metabolites in the glycolytic pathway such as phosphoenolpyruvate, 2-PG and 3-PG (Khandelwal et al, 1983;Dworkin & Dworkin-Rastl, 1987;Ueda & Plagens, 1987;Pek et al, 1990;Morino et al, 1991). Ueda and co-workers studied the 3-PGdependent phosphorylation of several unidentified proteins in a variety of mammalian tissues (Ueda & Plagens, 1987;Pek et al, 1990), focusing on the 3-PG-dependent phosphorylation of 72 and 155 kDa proteins in the bovine brain.…”

“…There have been a number of previous reports of cytosolic proteins whose phosphorylation state can be modulated by metabolites in the glycolytic pathway such as phosphoenolpyruvate, 2-PG and 3-PG (Khandelwal et al, 1983;Dworkin & Dworkin-Rastl, 1987;Ueda & Plagens, 1987;Pek et al, 1990;Morino et al, 1991). Ueda and co-workers studied the 3-PGdependent phosphorylation of several unidentified proteins in a variety of mammalian tissues (Ueda & Plagens, 1987;Pek et al, 1990), focusing on the 3-PG-dependent phosphorylation of 72 and 155 kDa proteins in the bovine brain. Although they attributed these 3-PG-dependent phosphorylations to the action of novel kinases (Ueda & Plagens, 1987), many (if not all) of these proteins are likely to be enzyme intermediates, phosphorylated by bisphosphorylated metabolites which become labelled in the presence of [y-32P]ATP, namely 1,3-biPG, 2,3-biPG, glucose 1,6-bisphosphate (G-1,6-biP) or fructose 2,6bisphosphate (F-2,6-biP), in a manner similar to that observed in this study.…”

“…On this basis, we hypothesized that PCr might play a role in modifying protein phosphorylation patterns. Modulation of protein phosphorylation by the glycolytic metabolites 2-and 3phosphoglycerate (2-PG, 3-PG) has been reported in cell-free extracts from a variety of mammalian tissues (Ueda & Plagens, 1987;Pek et al, 1990). It has been suggested that these phosphorylation events result from the action of novel kinases, and that they may be important in glycolytic regulation (Ueda & Plagens, 1987;Pek et al, 1990).…”