Linked Life Data

16870611

Source:http://linkedlifedata.com/resource/pubmed/id/16870611

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
39
pubmed:dateCreated
2006-9-25
pubmed:abstractText
Although the stimulatory effect of glucagon-like peptide 1 (GLP-1), a cAMP-generating agonist, on Ca(2+) signal and insulin secretion is well established, the underlying mechanisms remain to be fully elucidated. We recently discovered that Ca(2+) influx alone can activate conventional protein kinase C (PKC) as well as novel PKC in insulin-secreting (INS-1) cells. Building on this earlier finding, here we examined whether GLP-1-evoked Ca(2+) signaling can activate PKCalpha and PKCepsilon at a substimulatory concentration of glucose (3 mm) in INS-1 cells. We first showed that GLP-1 translocated endogenous PKCalpha and PKCepsilon from the cytosol to the plasma membrane. Next, we assessed the phosphorylation state of the PKC substrate, myristoylated alanine-rich C kinase substrate (MARCKS), by using MARCKS-GFP. GLP-1 translocated MARCKS-GFP to the cytosol in a Ca(2+)-dependent manner, and the GLP-1-evoked translocation of MARCKS-GFP was blocked by PKC inhibitors, either a broad PKC inhibitor, bisindolylmaleimide I, or a PKCepsilon inhibitor peptide, antennapedia peptide-fused pseudosubstrate PKCepsilon-(149-164) (antp-PKCepsilon) and a conventional PKC inhibitor, Gö-6976. Furthermore, forskolin-induced translocation of MARCKS-GFP was almost completely inhibited by U73122, a putative inhibitor of phospholipase C. These observations were verified in two different ways by demonstrating 1) forskolin-induced translocation of the GFP-tagged C1 domain of PKCgamma and 2) translocation of PKCalpha-DsRed and PKCepsilon-GFP. In addition, PKC inhibitors reduced forskolin-induced insulin secretion in both INS-1 cells and rat islets. Thus, GLP-1 can activate PKCalpha and PKCepsilon, and these GLP-1-activated PKCs may contribute considerably to insulin secretion at a substimulatory concentration of glucose.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
29
pubmed:volume
281
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
28499-507
pubmed:dateRevised
2011-11-17
pubmed:meshHeading
pubmed:year
2006
pubmed:articleTitle
Glucagon-like peptide 1 activates protein kinase C through Ca2+-dependent activation of phospholipase C in insulin-secreting cells.
pubmed:affiliation
Department of Physiology, Hamamatsu University School of Medicine, 1-20-1 Handayama, Hamamatsu 431-3192, Japan.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't