Functional regulation of transient receptor potential canonical 7 by cGMP-dependent protein kinase Iα

Cell Signal. 2011 Jul;23(7):1179-87. doi: 10.1016/j.cellsig.2011.03.005. Epub 2011 Mar 21.

Abstract

The cGMP/cGMP-dependent protein kinase (cGK) signaling pathway is implicated in the functional regulation of intracellular calcium levels. In the present study, we investigated the regulation of transient receptor potential canonical 7 (TRPC7) by the cGMP/cGK-I pathway. TRPC7 contains three putative cGK phosphorylation sites (Arg-Arg/Lys-Xaa-Ser/Thr). However, the role of cGK-I in the regulation of TRPC7 activity remains unclear. In vitro and in vivo kinase assays have revealed that cGK-Iα phosphorylates mouse TRPC7 but not mouse TRPC3. Site-directed mutagenesis analysis revealed that TRPC7 was phosphorylated by cGK-Iα at threonine 15. Phosphorylation of TRPC7 significantly suppressed carbachol-induced calcium influx and CREB phosphorylation. Furthermore, co-immunoprecipitation assay demonstrated that cGK-Iα interacted with the ankyrin repeat domain in the N terminus of TRPC7. cGK-Iβ also bound to TRPC7, while the type II regulatory subunit of cAMP-dependent protein kinase did not bind. These data indicate that cGK-Iα interacts with and phosphorylates TRPC7, contributing to the quick and accurate regulation of calcium influx and CREB phosphorylation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • COS Cells
  • Calcium Signaling
  • Carbachol / pharmacology
  • Chlorocebus aethiops
  • Cyclic AMP Response Element-Binding Protein / metabolism
  • Cyclic GMP-Dependent Protein Kinase Type I
  • Cyclic GMP-Dependent Protein Kinases / metabolism*
  • Enzyme Assays
  • HEK293 Cells
  • Humans
  • Isoenzymes / metabolism
  • Molecular Sequence Data
  • Mutagenesis, Site-Directed
  • Phosphorylation
  • Protein Binding
  • Recombinant Fusion Proteins / metabolism
  • TRPC Cation Channels / genetics
  • TRPC Cation Channels / metabolism*

Substances

  • CREB1 protein, human
  • Cyclic AMP Response Element-Binding Protein
  • Isoenzymes
  • Recombinant Fusion Proteins
  • TRPC Cation Channels
  • TRPC7 protein, human
  • Carbachol
  • Cyclic GMP-Dependent Protein Kinase Type I
  • Cyclic GMP-Dependent Protein Kinases
  • PRKG1 protein, human
  • Prkg1 protein, mouse