Inhibition of phosphatases and increased Ca2+ channel activity by inositol hexakisphosphate
Research output: Contribution to journal › Article
Colleges, School and Institutes
- Department of Medicine, Center for Molecular Medicine, Karolinska Institutet, Karolinska University Hospital, Stockholm, Sweden.
- Novum Unit
- School of Biochemistry
- University of South Alabama
- University Hospital of Hamburg-Eppendorf
Inositol hexakisphosphate (InsP6), the dominant inositol phosphate in insulin-secreting pancreatic β 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 β cell stimulus-secretion coupling.
|Number of pages||4|
|Publication status||Published - 17 Oct 1997|