PKCα promotes insulin secretion via TRPC1 phosphorylation in INS-1E cells

Biosci Biotechnol Biochem. 2019 Sep;83(9):1676-1682. doi: 10.1080/09168451.2019.1617106. Epub 2019 May 16.

Abstract

Protein kinase C (PKC) is a class of phospholipid-dependent serine/threonine kinases that contribute to cell survival, migration, and invasion. Previous studies demonstrated that PKC participates in insulin secretion. However, the role of PKC in glucose-stimulated insulin secretion (GSIS) remains unclear. Herein, we demonstrated that PKC is an important mediator of insulin secretion and revealed a close relationship between PKC activation and insulin secretion in INS-1E cells. Meanwhile, the presence of PKCα was found to induce TRPC1 phosphorylation in INS-1E cells. TRPC1 phosphorylation levels increased by activating PKCα activity. Inhibition of PKCα activity reduced TRPC1 phosphorylation. Finally, we showed that TRPC1 could reverse the decrease in intracellular Ca2+ levels and reduced insulin secretion induced by treatment with PKCα inhibitor under high glucose conditions. In conclusion, our findings indicated that TRPC1 and PKCα are involved in promoting insulin secretion and that PKCα promotes insulin secretion via TRPC1 phosphorylation in INS-1E cells.

Keywords: Protein kinase C α(PKCα); calcium(Ca); insulin secretion; transient receptor potential canonical channel-1 (TRPC1).

MeSH terms

  • Cell Line
  • Glucose / metabolism
  • Humans
  • Insulin Secretion*
  • Phosphorylation
  • Protein Kinase C-alpha / metabolism*
  • Signal Transduction
  • TRPC Cation Channels / metabolism*

Substances

  • TRPC Cation Channels
  • transient receptor potential cation channel, subfamily C, member 1
  • PRKCA protein, human
  • Protein Kinase C-alpha
  • Glucose