ATP depletion induces translocation of STIM1 to puncta and formation of STIM1-ORAI1 clusters: translocation and re-translocation of STIM1 does not require ATP.
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 puncta back to the ER was observed during total ATP depletion. We can therefore conclude that STIM1 translocation and re-translocation as well as formation of STIM1-ORAI1 clusters occur in an ATP-independent fashion and under conditions of PI(4,5)P(2) depletion.
Department of Physiology, The University of Liverpool, Crown Street, Liverpool, L69 3BX, UK.
Michael
M
Chvanov
Ciara M
CM
Walsh
Lee P
LP
Haynes
Svetlana G
SG
Voronina
Gyorgy
G
Lur
Oleg V
OV
Gerasimenko
Roger
R
Barraclough
Philip S
PS
Rudland
Ole H
OH
Petersen
Robert D
RD
Burgoyne
Alexei V
AV
Tepikin
D000255:Adenosine Triphosphate / Q000172:deficiency*; D000818:Animals; D015220:Calcium Channels / Q000235:genetics / Q000378:metabolism*; D020013:Calcium Signaling / Q000187:drug effects; D000252:Calcium-Transporting ATPases / Q000037:antagonists & inhibitors / Q000378:metabolism; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism*; D004721:Endoplasmic Reticulum / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006367:HeLa Cells; D006801:Humans; D007700:Kinetics; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D018613:Microscopy, Confocal; D009363:Neoplasm Proteins / Q000235:genetics / Q000378:metabolism*; D000071740:ORAI1 Protein; D019269:Phosphatidylinositol 4,5-Diphosphate / Q000378:metabolism; D011485:Protein Binding; D021381:Protein Transport; D051381:Rats; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D000071737:Stromal Interaction Molecule 1; D019284:Thapsigargin / Q000494:pharmacology; D014162:Transfection
D015220:Calcium Channels; D004791:Enzyme Inhibitors; D008565:Membrane Proteins; D009363:Neoplasm Proteins; D000071740:ORAI1 Protein; C510746:ORAI1 protein, human; D019269:Phosphatidylinositol 4,5-Diphosphate; D011993:Recombinant Fusion Proteins; C103530:STIM1 protein, human; D000071737:Stromal Interaction Molecule 1; D019284:Thapsigargin; D000255:Adenosine Triphosphate; D000252:Calcium-Transporting ATPases