ATP depletion induces translocation of STIM1 to puncta and formation of STIM1-ORAI1 clusters: translocation and re-translocation of STIM1 does not require ATP.

ABSTRACT: Depletion of the endoplasmic reticulum (ER) calcium store triggers translocation of stromal interacting molecule one (STIM1) to the sub-plasmalemmal region and formation of puncta-structures in which STIM1 interacts and activates calcium channels. ATP depletion induced the formation of STIM1 puncta in PANC1, RAMA37, and HeLa cells. The sequence of events triggered by inhibition of ATP production included a rapid decline of ATP, depletion of phosphatidylinositol 4,5-bisphosphate (PI(4,5)P(2)) and a slow calcium leak from the ER followed by formation of STIM1 puncta. STIM1 puncta induced by ATP depletion were co-localized with clusters of ORAI1 channels. STIM1-ORAI1 clusters that developed as a result of ATP depletion were very poor mediators of Ca(2+) influx. Re-translocation of STIM1 from

SUBMITTER: Chvanov M 

PROVIDER: S-EPMC2770109 | biostudies-literature | 2008 Nov

REPOSITORIES: biostudies-literature