Protein Kinases, Protein Phosphorylation, and the Regulation of Insulin Secretion from Pancreatic  -Cells.

1998 ◽  
Vol 19 (4) ◽  
pp. 429-461 ◽  
Author(s):  
P. M. Jones
Keyword(s):  
Insulin Secretion ◽  
Protein Phosphorylation ◽  
Protein Kinases ◽  
Pancreatic Cells

Local Integrin Activation in Pancreatic Cells Targets Insulin Secretion to the Vasculature

2018 ◽  
Author(s):  
WannJun Gan ◽  
OanhhHoang Do ◽  
Louise Cottle ◽  
Elena Kosobrodova ◽  
Justin CooperrWhite ◽  
...  
Keyword(s):  
Insulin Secretion ◽  
Integrin Activation ◽  
Pancreatic Cells

scholarly journals Ca2+-induced insulin secretion from electrically permeabilized islets. Loss of the Ca2+-induced secretory response is accompanied by loss of Ca2+-induced protein phosphorylation

1992 ◽  
Vol 285 (3) ◽  
pp. 973-978 ◽  
Author(s):  
P M Jones ◽  
S J Persaud ◽  
S L Howell
Keyword(s):  
Protein Kinase C ◽  
Insulin Secretion ◽  
Protein Kinase ◽  
Cyclic Amp ◽  
Protein Phosphorylation ◽  
Prolonged Exposure ◽  
Kinase C ◽  
Dependent Protein ◽  
32P Incorporation ◽  
Rat Islets Of Langerhans

Increasing the cytosolic Ca2+ concentration of electrically permeabilized rat islets of Langerhans caused rapid increases in insulin secretion and in 32P incorporation into islet proteins. However, the secretory responsiveness of permeabilized islets was relatively transient, with insulin secretion approaching basal levels within 20-30 min despite the continued presence of stimulatory concentrations of Ca2+. The loss of Ca2(+)-induced insulin secretion was accompanied by a marked reduction in Ca2(+)-dependent protein phosphorylation, but not in cyclic AMP-dependent protein phosphorylation. Similarly, permeabilized islets which were no longer responsive to Ca2+ were able to mount appropriate secretory responses to cyclic AMP and to a protein kinase C-activating phorbol ester. These results suggest that prolonged exposure to elevated cytosolic Ca2+ concentrations results in a specific desensitization of the secretory mechanism to Ca2+, perhaps as a result of a decrease in Ca2(+)-dependent kinase activity. Furthermore, these studies suggest that secretory responses of B-cells to cyclic AMP and activators of protein kinase C are not dependent upon the responsiveness of the cells to changes in cytosolic Ca2+.

scholarly journals Structural Insights into Protein Regulation by Phosphorylation and Substrate Recognition of Protein Kinases/Phosphatases

Life ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 957
Author(s):  
Seung-Hyeon Seok
Keyword(s):  
Protein Phosphorylation ◽  
Protein Kinases ◽  
Protein Phosphatases ◽  
Substrate Recognition ◽  
Protein Structures ◽  
Phosphate Group ◽  
Amino Acid Side Chain ◽  
Post Translational Modification ◽  
Cellular Processes ◽  
Structural Insights

Protein phosphorylation is one of the most widely observed and important post-translational modification (PTM) processes. Protein phosphorylation is regulated by protein kinases, each of which covalently attaches a phosphate group to an amino acid side chain on a serine (Ser), threonine (Thr), or tyrosine (Tyr) residue of a protein, and by protein phosphatases, each of which, conversely, removes a phosphate group from a phosphoprotein. These reversible enzyme activities provide a regulatory mechanism by activating or deactivating many diverse functions of proteins in various cellular processes. In this review, their structures and substrate recognition are described and summarized, focusing on Ser/Thr protein kinases and protein Ser/Thr phosphatases, and the regulation of protein structures by phosphorylation. The studies reviewed here and the resulting information could contribute to further structural, biochemical, and combined studies on the mechanisms of protein phosphorylation and to drug discovery approaches targeting protein kinases or protein phosphatases.

Surface Protein Phosphorylation by Ecto-Protein Kinases

1998 ◽  
pp. 51-71 ◽  
Author(s):  
Yigal H. Ehrlich ◽  
Michael V. Hogan ◽  
Zofia Pawlowska ◽  
Andrzej Wieraszko ◽  
Ethel Katz ◽  
...  
Keyword(s):  
Protein Phosphorylation ◽  
Protein Kinases ◽  
Surface Protein

Insulin secretion and protein phosphorylation in PKC-depleted islets of langerhans

Life Sciences ◽  
1992 ◽  
Vol 50 (11) ◽  
pp. 761-767 ◽  
Author(s):  
Peter M. Jones ◽  
Shanta J. Persaud ◽  
Simon L. Howell
Keyword(s):  
Insulin Secretion ◽  
Protein Phosphorylation ◽  
Islets Of Langerhans
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