Claim: Oscillation of Ca concentration is directly affected by the signal-transduction activity of P2Y1 (functions as a receptor for extracellular ATP and ADP), which is linked to a signal cascade originating in regulation of the flow of Ca and K ions by the receptor's interactions with G proteins, modulating access to Ca and K channels.
Evidence: Oscillation of Ca concentration is directly affected by the signal-transduction activity of P2Y1; specifically, through protein kinase C phosphorylation of Thr339 in the carboxy terminus of the P2Y1 receptor. This receptor functions as a receptor for extracellular ATP and ADP. The activity of P2Y receptors is linked to a signal cascade originating in regulation of the flow of Ca and K ions by the receptor's interactions with G proteins, modulating access to Ca and K channels, though the exact behavior is dependent upon individual receptor species.