| Structural highlights
Disease
STIM1_HUMAN Defects in STIM1 are the cause of immune dysfunction with T-cell inactivation due to calcium entry defect type 2 (IDTICED2) [MIM:612783. IDTICED2 is an immune disorder characterized by recurrent infections, impaired T-cell activation and proliferative response, decreased T-cell production of cytokines, lymphadenopathy, and normal lymphocytes counts and serum immunoglobulin levels. Additional features include thrombocytopenia, autoimmune hemolytic anemia, non-progressive myopathy, partial iris hypoplasia, hepatosplenomegaly and defective enamel dentition.[1]
Function
STIM1_HUMAN Plays a role in mediating store-operated Ca(2+) entry (SOCE), a Ca(2+) influx following depletion of intracellular Ca(2+) stores. Acts as Ca(2+) sensor in the endoplasmic reticulum via its EF-hand domain. Upon Ca(2+) depletion, translocates from the endoplasmic reticulum to the plasma membrane where it activates the Ca(2+) release-activated Ca(2+) (CRAC) channel subunit, TMEM142A/ORAI1.[2] [3] [4] [5] [6] [7] [8] [9] [10]
Publication Abstract from PubMed
Orai1 calcium channels in the plasma membrane are activated by stromal interaction molecule-1 (STIM1), an endoplasmic reticulum calcium sensor, to mediate store-operated calcium entry (SOCE). The cytosolic region of STIM1 contains a long putative coiled-coil (CC)1 segment and shorter CC2 and CC3 domains. Here we present solution nuclear magnetic resonance structures of a trypsin-resistant CC1-CC2 fragment in the apo and Orai1-bound states. Each CC1-CC2 subunit forms a U-shaped structure that homodimerizes through antiparallel interactions between equivalent alpha-helices. The CC2:CC2' helix pair clamps two identical acidic Orai1 C-terminal helices at opposite ends of a hydrophobic/basic STIM-Orai association pocket. STIM1 mutants disrupting CC1:CC1' interactions attenuate, while variants promoting CC1 stability spontaneously activate Orai1 currents. CC2 mutations cause remarkable variability in Orai1 activation because of a dual function in binding Orai1 and autoinhibiting STIM1 oligomerization via interactions with CC3. We conclude that SOCE is activated through dynamic interplay between STIM1 and Orai1 helices.
STIM1/Orai1 coiled-coil interplay in the regulation of store-operated calcium entry.,Stathopulos PB, Schindl R, Fahrner M, Zheng L, Gasmi-Seabrook GM, Muik M, Romanin C, Ikura M Nat Commun. 2013 Dec 19;4:2963. doi: 10.1038/ncomms3963. PMID:24351972[11]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Picard C, McCarl CA, Papolos A, Khalil S, Luthy K, Hivroz C, LeDeist F, Rieux-Laucat F, Rechavi G, Rao A, Fischer A, Feske S. STIM1 mutation associated with a syndrome of immunodeficiency and autoimmunity. N Engl J Med. 2009 May 7;360(19):1971-80. doi: 10.1056/NEJMoa0900082. PMID:19420366 doi:http://dx.doi.org/10.1056/NEJMoa0900082
- ↑ Sabbioni S, Barbanti-Brodano G, Croce CM, Negrini M. GOK: a gene at 11p15 involved in rhabdomyosarcoma and rhabdoid tumor development. Cancer Res. 1997 Oct 15;57(20):4493-7. PMID:9377559
- ↑ Liou J, Kim ML, Heo WD, Jones JT, Myers JW, Ferrell JE Jr, Meyer T. STIM is a Ca2+ sensor essential for Ca2+-store-depletion-triggered Ca2+ influx. Curr Biol. 2005 Jul 12;15(13):1235-41. PMID:16005298 doi:10.1016/j.cub.2005.05.055
- ↑ Roos J, DiGregorio PJ, Yeromin AV, Ohlsen K, Lioudyno M, Zhang S, Safrina O, Kozak JA, Wagner SL, Cahalan MD, Velicelebi G, Stauderman KA. STIM1, an essential and conserved component of store-operated Ca2+ channel function. J Cell Biol. 2005 May 9;169(3):435-45. Epub 2005 May 2. PMID:15866891 doi:jcb.200502019
- ↑ Zhang SL, Yu Y, Roos J, Kozak JA, Deerinck TJ, Ellisman MH, Stauderman KA, Cahalan MD. STIM1 is a Ca2+ sensor that activates CRAC channels and migrates from the Ca2+ store to the plasma membrane. Nature. 2005 Oct 6;437(7060):902-5. PMID:16208375 doi:nature04147
- ↑ Mercer JC, Dehaven WI, Smyth JT, Wedel B, Boyles RR, Bird GS, Putney JW Jr. Large store-operated calcium selective currents due to co-expression of Orai1 or Orai2 with the intracellular calcium sensor, Stim1. J Biol Chem. 2006 Aug 25;281(34):24979-90. Epub 2006 Jun 28. PMID:16807233 doi:M604589200
- ↑ Soboloff J, Spassova MA, Tang XD, Hewavitharana T, Xu W, Gill DL. Orai1 and STIM reconstitute store-operated calcium channel function. J Biol Chem. 2006 Jul 28;281(30):20661-5. Epub 2006 Jun 9. PMID:16766533 doi:10.1074/jbc.C600126200
- ↑ Peinelt C, Vig M, Koomoa DL, Beck A, Nadler MJ, Koblan-Huberson M, Lis A, Fleig A, Penner R, Kinet JP. Amplification of CRAC current by STIM1 and CRACM1 (Orai1). Nat Cell Biol. 2006 Jul;8(7):771-3. Epub 2006 May 30. PMID:16733527 doi:ncb1435
- ↑ Spassova MA, Soboloff J, He LP, Xu W, Dziadek MA, Gill DL. STIM1 has a plasma membrane role in the activation of store-operated Ca(2+) channels. Proc Natl Acad Sci U S A. 2006 Mar 14;103(11):4040-5. Epub 2006 Mar 6. PMID:16537481 doi:0510050103
- ↑ Palty R, Raveh A, Kaminsky I, Meller R, Reuveny E. SARAF inactivates the store operated calcium entry machinery to prevent excess calcium refilling. Cell. 2012 Apr 13;149(2):425-38. doi: 10.1016/j.cell.2012.01.055. Epub 2012 Mar, 29. PMID:22464749 doi:10.1016/j.cell.2012.01.055
- ↑ Stathopulos PB, Schindl R, Fahrner M, Zheng L, Gasmi-Seabrook GM, Muik M, Romanin C, Ikura M. STIM1/Orai1 coiled-coil interplay in the regulation of store-operated calcium entry. Nat Commun. 2013 Dec 19;4:2963. doi: 10.1038/ncomms3963. PMID:24351972 doi:http://dx.doi.org/10.1038/ncomms3963
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