title: The serine 814 of TRPC6 is phosphorylated under unstimulated conditions.
abstract: TRPC are nonselective cation channels involved in calcium entry. Their regulation by phosphorylation has been shown to modulate their routing and activity. TRPC6 activity increases following phosphorylation by Fyn, and is inhibited by protein kinase G and protein kinase C. A previous study by our group showed that TRPC6 is phosphorylated under unstimulated conditions in a human embryonic kidney cells line (HEK293). To investigate the mechanism responsible for this phosphorylation, we used a MS/MS approach combined with metabolic labeling and showed that the serine at position 814 is phosphorylated in unstimulated cells. The mutation of Ser(814) into Ala decreased basal phosphorylation but did not modify TRPC6 activity. Even though Ser(814) is within a consensus site for casein kinase II (CK2), we showed that CK2 is not involved in the phosphorylation of TRPC6 and does not modify its activity. In summary, we identified a new basal phosphorylation site (Ser(814)) on TRPC6 and showed that CK2 is not responsible for the phosphorylation of this site.
authors: Department of Pharmacology, Université de Sherbrooke, Sherbrooke, Québec, Canada.
authors: Simon M
authors: SM
authors: Bousquet
authors: Michael
authors: M
authors: Monet
authors: Guylain
authors: G
authors: Boulay
mesh_terms: D000595:Amino Acid Sequence; D019943:Amino Acid Substitution / Q000235:genetics; D000818:Animals; D047390:Casein Kinase II / Q000037:antagonists & inhibitors; D057809:HEK293 Cells; D006801:Humans; D013058:Mass Spectrometry; D051379:Mice; D008969:Molecular Sequence Data; D050505:Mutant Proteins / Q000737:chemistry / Q000378:metabolism; D009154:Mutation / Q000235:genetics; D010766:Phosphorylation / Q000187:drug effects; D010768:Phosphoserine / Q000737:chemistry / Q000378:metabolism*; D047428:Protein Kinase Inhibitors / Q000494:pharmacology; D021381:Protein Transport / Q000187:drug effects; D013194:Staining and Labeling; D050052:TRPC Cation Channels / Q000378:metabolism*; D000074287:TRPC6 Cation Channel
chemical_list: D050505:Mutant Proteins; D047428:Protein Kinase Inhibitors; D050052:TRPC Cation Channels; D000074287:TRPC6 Cation Channel; C492146:Trpc6 protein, mouse; D010768:Phosphoserine; D047390:Casein Kinase II