Regulation of IP3receptors by cyclic AMP.
Ca2+and cAMP are ubiquitous intracellular messengers and interactions between them are commonplace. Here the effects of cAMP on inositol 1,4,5-trisphosphate receptors (IP3Rs) are briefly reviewed. All three subtypes of IP3R are phosphorylated by cAMP-dependent protein kinase (PKA). This potentiates IP3-evoked Ca2+release through IP3R1 and IP3R2, but probably has little effect on IP3R3. In addition, cAMP can directly sensitize all three IP3R subtypes to IP3. The high concentrations of cAMP required for this PKA-independent modulation of IP3Rs is delivered to them within signalling junctions that include type 6 adenylyl cyclase and IP3R2.
Department of Pharmacology, University of Cambridge, Tennis Court Road, Cambridge CB2 1PD, UK. Electronic address: cwt1000@cam.ac.uk.
Colin W
CW
Taylor
D000818:Animals; D002118:Calcium / Q000378:metabolism*; D020013:Calcium Signaling; D000242:Cyclic AMP / Q000494:pharmacology*; D005786:Gene Expression Regulation / Q000187:drug effects*; D006801:Humans; D053496:Inositol 1,4,5-Trisphosphate Receptors / Q000378:metabolism*
D053496:Inositol 1,4,5-Trisphosphate Receptors; D000242:Cyclic AMP; D002118:Calcium
Ca(2+) stores; Cyclic AMP; IP(3) receptor; Parathyroid hormone; Protein kinase A; Signalling junctions