Download MendeleyStructural and mechanistic insights into STIM1-mediated initiation of store-operated calcium entry.
Stathopulos, P.B., Zheng, L., Li, G.Y., Plevin, M.J., Ikura, M.(2008) Cell 135: 110-122
- PubMed: 18854159 Search on PubMed
- DOI: https://doi.org/10.1016/j.cell.2008.08.006
- Primary Citation Related Structures:
2K60 - PubMed Abstract:
Stromal interaction molecule-1 (STIM1) activates store-operated Ca2+ entry (SOCE) in response to diminished luminal Ca2+ levels. Here, we present the atomic structure of the Ca2+-sensing region of STIM1 consisting of the EF-hand and sterile alpha motif (SAM) domains (EF-SAM). The canonical EF-hand is paired with a previously unidentified EF-hand. Together, the EF-hand pair mediates mutually indispensable hydrophobic interactions between the EF-hand and SAM domains. Structurally critical mutations in the canonical EF-hand, "hidden" EF-hand, or SAM domain disrupt Ca2+ sensitivity in oligomerization via destabilization of the entire EF-SAM entity. In mammalian cells, EF-SAM destabilization mutations within full-length STIM1 induce punctae formation and activate SOCE independent of luminal Ca2+. We provide atomic resolution insight into the molecular basis for STIM1-mediated SOCE initiation and show that the folded/unfolded state of the Ca2+-sensing region of STIM is crucial to SOCE regulation.
- Division of Signaling Biology, Ontario Cancer Institute and Department of Medical Biophysics, University of Toronto, Toronto Medical Discovery Tower, MaRS Centre, 101 College Street, Toronto, Ontario M5G 1L7, Canada.
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