Linked Life Data

10078549

Source:http://linkedlifedata.com/resource/pubmed/id/10078549

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1999-3-30
pubmed:abstractText
Increasing evidence supports a physiological role of Ca2+/calmodulin-dependent protein kinase II (CaM kinase II) in the secretion of insulin from the pancreatic beta-cell, but the precise sites of action are not known. A role of this enzyme in neuroexocytosis is implicated by its phosphorylation of a vesicle-associated protein, synapsin I. Because of emerging similarities to the neuron with respect to exocytotic mechanisms, the expression and phosphorylation of synapsin I in the beta-cell have been studied. Synapsin I expression in clonal mouse beta-cells (betaTC3) and primary rat islet beta-cells was initially confirmed by immunoblot analysis. By immunoprecipitation, in situ phosphorylation of synapsin I was induced in permeabilized betaTC3 cells within a Ca2+ concentration range shown to activate endogenous CaM kinase II under identical conditions. Proteolytic digests of these immunoprecipitates revealed that calcium primarily induced the increased phosphorylation of sites identified as CaM kinase II-specific and distinct from protein kinase A-specific sites. Immunofluorescence and immunogold electron microscopy verified synapsin I expression in betaTC3 cells and pancreatic slices but demonstrated little if any colocalization of synapsin I with insulin-containing dense core granules. Thus, although this study establishes that synapsin I is a substrate for CaM kinase II in the pancreatic beta-cell, this event appears not to be important for the mobilization of insulin granules.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
AIM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0012-1797
pubmed:author
pubmed:issnType
Print
pubmed:volume
48
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
499-506
pubmed:dateRevised
2011-11-17
pubmed:meshHeading
pubmed-meshheading:10078549-Animals, pubmed-meshheading:10078549-Calcium-Calmodulin-Dependent Protein Kinase Type 2, pubmed-meshheading:10078549-Calcium-Calmodulin-Dependent Protein Kinases, pubmed-meshheading:10078549-Cells, Cultured, pubmed-meshheading:10078549-Clone Cells, pubmed-meshheading:10078549-Cyclic AMP-Dependent Protein Kinases, pubmed-meshheading:10078549-Cytoplasmic Granules, pubmed-meshheading:10078549-Fluorescent Antibody Technique, Indirect, pubmed-meshheading:10078549-Insulin, pubmed-meshheading:10078549-Insulinoma, pubmed-meshheading:10078549-Islets of Langerhans, pubmed-meshheading:10078549-Kinetics, pubmed-meshheading:10078549-Mice, pubmed-meshheading:10078549-Pancreatic Neoplasms, pubmed-meshheading:10078549-Peptide Mapping, pubmed-meshheading:10078549-Phosphopeptides, pubmed-meshheading:10078549-Phosphorylation, pubmed-meshheading:10078549-Rats, pubmed-meshheading:10078549-Substrate Specificity, pubmed-meshheading:10078549-Synapsins, pubmed-meshheading:10078549-Tumor Cells, Cultured
pubmed:year
1999
pubmed:articleTitle
Site-specific phosphorylation of synapsin I by Ca2+/calmodulin-dependent protein kinase II in pancreatic betaTC3 cells: synapsin I is not associated with insulin secretory granules.
pubmed:affiliation
Department of Biochemistry and Molecular Biology, University of North Texas Health Science Center at Fort Worth, 76107-2699, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, U.S. Gov't, Non-P.H.S.