Distinct intracellular sAC-cAMP domains regulate ER Ca2+ signaling and OXPHOS function

作者：Valsecchi Federica; Konrad Csaba; D'Aurelio Marilena; Ramos Espiritu Lavoisier S; Stepanova Anna; Burstein Suzanne R; Galkin Alexander; Magrane Jordi; Starkov Anatoly; Buck Jochen; Levin Lonny R; Manfredi Giovanni^*

来源：Journal of Cell Science, 2017, 130(21): 3713-3727.

DOI：10.1242/jcs.206318

• Mitochondria
• Soluble adenylyl cyclase
• SAC
• Calcium
• IP3R
• Oxidative phosphorylation

cAMP regulates a wide variety of physiological functions in mammals. This single second messenger can regulate multiple, seemingly disparate functions within independently regulated cell compartments. We have previously identified one such compartment inside the matrix of the mitochondria, where soluble adenylyl cyclase (sAC) regulates oxidative phosphorylation (OXPHOS). We now show that sAC knockout fibroblasts have a defect in OXPHOS activity and attempt to compensate for this defect by increasing OXPHOS proteins. Importantly, sAC knockout cells also exhibit decreased probability of endoplasmic reticulum (ER) Ca2+ release associated with diminished phosphorylation of the inositol 3-phosphate receptor. Restoring sAC expression exclusively in the mitochondrial matrix rescues OXPHOS activity and reduces mitochondrial biogenesis, indicating that these phenotypes are regulated by intramitochondrial sAC. In contrast, Ca2+ release from the ER is only rescued when sAC expression is restored throughout the cell. Thus, we show that functionally distinct, sAC-defined, intracellular cAMP signaling domains regulate metabolism and Ca2+ signaling.

• 出版日期2017-11-1