1. Functional regulation of transient receptor potential canonical 7 by cGMP-dependent protein kinase Iα
- Author
-
Keizo Yuasa, Akihiko Tsuji, and Taito Matsuda
- Subjects
Recombinant Fusion Proteins ,Molecular Sequence Data ,Biology ,Mitogen-activated protein kinase kinase ,MAP2K7 ,TRPC3 ,Chlorocebus aethiops ,Cyclic GMP-Dependent Protein Kinases ,Animals ,Humans ,Amino Acid Sequence ,Calcium Signaling ,Phosphorylation ,Protein kinase A ,Cyclic AMP Response Element-Binding Protein ,Cyclic GMP-Dependent Protein Kinase Type I ,Enzyme Assays ,TRPC Cation Channels ,Kinase ,Cell Biology ,Molecular biology ,Isoenzymes ,HEK293 Cells ,COS Cells ,Mutagenesis, Site-Directed ,Carbachol ,Signal transduction ,cGMP-dependent protein kinase ,Protein Binding - 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.
- Published
- 2011