Coupling of STIM1 to store-operated Ca2+ entry through its constitutive and inducible movement in the endoplasmic reticulum

Yoshihiro Baba, Kenji Hayashi, Yoko Fujii, Akiko Mizushima, Hiroshi Watarai, Minoru Wakamori, Takuro Numaga, Yasuo Mori, Masamitsu Iino, Masaki Hikida, Tomohiro Kurosaki

Research output: Contribution to journalArticlepeer-review

261 Citations (Scopus)


Depletion of intracellular calcium (Ca2+) stores induces store-operated Ca2+ (SOC) entry across the plasma membrane (PM). STIM1, a putative Ca2+ sensor in the endoplasmic reticulum (ER), has been recently shown to be necessary for SOC channel activation. Here we show that STIM1 dynamically moves in tubulovesicular shape on the ER and its subcompartment in resting living cells, whereas, upon Ca2+ store depletion, it is rapidly redistributed into discrete puncta that are located underneath, but not inserted into the PM. Normal constitutive movement of STIM1 s mediated through the coiled-coil and Ser/Thr-rich C-terminal domains in the cytoplasmic region of STIM1, whereas subsequent inducible puncta formation further requires the sterile α motif domain protruding into the ER lumen. Each of these three domains (coiled-coil, Ser/Thr-rich, and sterile α motif) was essential for activating SOC channels. Hence, our findings based on structure-function experiments suggest that constitutive dynamic movement of STIM1 in the ER and its subcompartment is obligatory for subsequent depletion-dependent redistribution of STIM1 into puncta underneath the PM and activation of SOC channels.

Original languageEnglish
Pages (from-to)16704-16709
Number of pages6
JournalProceedings of the National Academy of Sciences of the United States of America
Issue number45
Publication statusPublished - 2006 Nov 7
Externally publishedYes


  • B cell receptor
  • Calcium signaling
  • DT40
  • Store-operated calcium

ASJC Scopus subject areas

  • General


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