Uncoupling protein 3 (UCP3) modulates the activity of Sarco/endoplasmic reticulum Ca2+-ATPase (SERCA) by decreasing mitochondrial ATP production.

ABSTRACT: The uncoupling proteins UCP2 and UCP3 have been postulated to catalyze Ca(2+) entry across the inner membrane of mitochondria, but this proposal is disputed, and other, unrelated proteins have since been identified as the mitochondrial Ca(2+) uniporter. To clarify the role of UCPs in mitochondrial Ca(2+) handling, we down-regulated the expression of the only uncoupling protein of HeLa cells, UCP3, and measured Ca(2+) and ATP levels in the cytosol and in organelles with genetically encoded probes. UCP3 silencing did not alter mitochondrial Ca(2+) uptake in permeabilized cells. In intact cells, however, UCP3 depletion increased mitochondrial ATP production and strongly reduced the cytosolic and mitochondrial Ca(2+) elevations evoked by histamine. The reduced Ca(2+) elevations were due to inh

SUBMITTER: De Marchi U 

PROVIDER: S-EPMC3173197 | biostudies-literature | 2011 Sep

REPOSITORIES: biostudies-literature