Bicarbonate, carbon dioxide and pH sensing via mammalian bicarbonate-regulated soluble adenylyl cyclase

Soluble adenylyl cyclase (sAC; ADCY10) is a bicarbonate (HCO3 − )-regulated enzyme responsible for the generation of cyclic adenosine monophosphate (cAMP). sAC is distributed throughout the cell and within organelles and, as such, plays a role in numerous cellular signalling pathways. Carbonic anhydrases (CAs) nearly instantaneously equilibrate HCO3 − , protons and carbon dioxide (CO2 ); because of the ubiquitous presence of CAs within cells, HCO3 − -regulated sAC can respond to changes in any of these factors. Thus, sAC can function as a physiological HCO3 − /CO2 /pH sensor. Here, we outline examples where we have shown that sAC responds to changes in HCO3 − , CO2 or pH to regulate diverse physiological functions.