Publication Date:
1997-10-23
Description:
Inositol hexakisphosphate (InsP6), the dominant inositol phosphate in insulin-secreting pancreatic beta cells, inhibited the serine-threonine protein phosphatases type 1, type 2A, and type 3 in a concentration-dependent manner. The activity of voltage-gated L-type calcium channels is increased in cells treated with inhibitors of serine-threonine protein phosphatases. Thus, the increased calcium channel activity obtained in the presence of InsP6 might result from the inhibition of phosphatase activity. Glucose elicited a transient increase in InsP6 concentration, which indicates that this inositol polyphosphate may modulate calcium influx over the plasma membrane and serve as a signal in the pancreatic beta cell stimulus-secretion coupling.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Larsson, O -- Barker, C J -- Sjoholm, A -- Carlqvist, H -- Michell, R H -- Bertorello, A -- Nilsson, T -- Honkanen, R E -- Mayr, G W -- Zwiller, J -- Berggren, P O -- New York, N.Y. -- Science. 1997 Oct 17;278(5337):471-4.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Rolf Luft Center for Diabetes Research, Department of Molecular Medicine, Karolinska Institute, S-171 76 Stockholm, Sweden.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/9334307" target="_blank"〉PubMed〈/a〉
Keywords:
Animals
;
Calcium/metabolism
;
Calcium Channels/drug effects/*metabolism
;
Cell Membrane/metabolism
;
Cricetinae
;
Dose-Response Relationship, Drug
;
Glucose/pharmacology
;
Inositol/pharmacology
;
Inositol Phosphates/pharmacology
;
Ion Channel Gating
;
Islets of Langerhans/drug effects/*metabolism
;
Patch-Clamp Techniques
;
Phosphoprotein Phosphatases/*antagonists & inhibitors
;
Phytic Acid/*pharmacology
;
Tumor Cells, Cultured
Print ISSN:
0036-8075
Electronic ISSN:
1095-9203
Topics:
Biology
,
Chemistry and Pharmacology
,
Computer Science
,
Medicine
,
Natural Sciences in General
,
Physics
