Termination and activation of store-operated cyclic AMP production.
Diverse pathophysiological processes (e.g. obesity, lifespan determination, addiction and male fertility) have been linked to the expression of specific isoforms of the adenylyl cyclases (AC1-AC10), the enzymes that generate cyclic AMP (cAMP). Our laboratory recently discovered a new mode of cAMP production, prominent in certain cell types, that is stimulated by any manoeuvre causing reduction of free [Ca(2+) ] within the lumen of the endoplasmic reticulum (ER) calcium store. Activation of this 'store-operated' pathway requires the ER Ca(2+)  sensor, STIM1, but the identity of the enzymes responsible for cAMP production and how this process is regulated is unknown. Here, we used sensitive FRET-based sensors for cAMP in single cells combined with silencing and overexpression approaches to show that store-operated cAMP production occurred preferentially via the isoform AC3 in NCM460 colonic epithelial cells. Ca(2+)  entry via the plasma membrane Ca(2+)  channel, Orai1, suppressed cAMP production, independent of store refilling. These findings are an important first step towards defining the functional significance and to identify the protein composition of this novel Ca(2+) /cAMP crosstalk system.
VA Boston Healthcare System, Department of Surgery, Brigham and Women's Hospital, Harvard Medical School, West Roxbury, MA 02132, USA.
Isabella
I
Maiellaro
Konstantinos
K
Lefkimmiatis
Mary Pat
MP
Moyer
Silvana
S
Curci
Aldebaran M
AM
Hofer
D000262:Adenylyl Cyclases / Q000235:genetics / Q000378:metabolism*; D015374:Biosensing Techniques; D002118:Calcium / Q000378:metabolism; D015220:Calcium Channels / Q000235:genetics / Q000378:metabolism*; D054732:Calcium-Calmodulin-Dependent Protein Kinase Type 2 / Q000037:antagonists & inhibitors; D015815:Cell Adhesion Molecules / Q000235:genetics / Q000378:metabolism; D002460:Cell Line / Q000187:drug effects; D000242:Cyclic AMP / Q000378:metabolism*; D004721:Endoplasmic Reticulum / Q000187:drug effects / Q000378:metabolism*; D031541:Fluorescence Resonance Energy Transfer; D055785:Gene Knockdown Techniques; D006367:HeLa Cells; D006801:Humans; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism; D009363:Neoplasm Proteins / Q000235:genetics / Q000378:metabolism; D000071740:ORAI1 Protein; D037342:Pertussis Toxin / Q000494:pharmacology; D047428:Protein Kinase Inhibitors / Q000494:pharmacology; D000071737:Stromal Interaction Molecule 1; D000071738:Stromal Interaction Molecule 2
D015220:Calcium Channels; D015815:Cell Adhesion Molecules; D008565:Membrane Proteins; D009363:Neoplasm Proteins; D000071740:ORAI1 Protein; C510746:ORAI1 protein, human; D047428:Protein Kinase Inhibitors; C103530:STIM1 protein, human; C513279:STIM2 protein, human; D000071737:Stromal Interaction Molecule 1; D000071738:Stromal Interaction Molecule 2; D000242:Cyclic AMP; D037342:Pertussis Toxin; D054732:Calcium-Calmodulin-Dependent Protein Kinase Type 2; D000262:Adenylyl Cyclases; C421784:adenylate cyclase 3; C121100:adenylyl cyclase 6; C419510:adenylyl cyclase type V; D002118:Calcium