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STIM1 Is a MT-Plus-End-Tracking Protein Involved in Remodeling of the ER

2008; Elsevier BV; Volume: 18; Issue: 3 Linguagem: Inglês

10.1016/j.cub.2007.12.050

1879-0445

Ilya Grigoriev, Susana Montenegro Gouveia, Babet van der Vaart, Jeroen Demmers, Jeremy T. Smyth, Srinivas Honnappa, Daniël Splinter, Michel O. Steinmetz, James W. Putney, Casper C. Hoogenraad, Anna Akhmanova,

Herbal Medicine Research Studies

Stromal interaction molecule 1 (STIM1) is a transmembrane protein that is essential for store-operated Ca2+ entry, a process of extracellular Ca2+ influx in response to the depletion of Ca2+ stores in the endoplasmic reticulum (ER) (reviewed in [1Luik R.M. Lewis R.S. New insights into the molecular mechanisms of store-operated Ca2+ signaling in T cells.Trends Mol. Med. 2007; 13: 103-107Abstract Full Text Full Text PDF PubMed Scopus (51) Google Scholar, 2Putney Jr., J.W. New molecular players in capacitative Ca2+ entry.J. Cell Sci. 2007; 120: 1959-1965Crossref PubMed Scopus (131) Google Scholar, 3Hogan P.G. Rao A. Dissecting ICRAC, a store-operated calcium current.Trends Biochem. Sci. 2007; 32: 235-245Abstract Full Text Full Text PDF PubMed Scopus (100) Google Scholar, 4Wu M.M. Luik R.M. Lewis R.S. Some assembly required: Constructing the elementary units of store-operated Ca(2+) entry.Cell Calcium. 2007; 42: 163-172Crossref PubMed Scopus (68) Google Scholar]). STIM1 localizes predominantly to the ER; upon Ca2+ release from the ER, STIM1 translocates to the ER-plasma membrane junctions and activates Ca2+ channels (reviewed in [1Luik R.M. Lewis R.S. New insights into the molecular mechanisms of store-operated Ca2+ signaling in T cells.Trends Mol. Med. 2007; 13: 103-107Abstract Full Text Full Text PDF PubMed Scopus (51) Google Scholar, 2Putney Jr., J.W. New molecular players in capacitative Ca2+ entry.J. Cell Sci. 2007; 120: 1959-1965Crossref PubMed Scopus (131) Google Scholar, 3Hogan P.G. Rao A. Dissecting ICRAC, a store-operated calcium current.Trends Biochem. Sci. 2007; 32: 235-245Abstract Full Text Full Text PDF PubMed Scopus (100) Google Scholar, 4Wu M.M. Luik R.M. Lewis R.S. Some assembly required: Constructing the elementary units of store-operated Ca(2+) entry.Cell Calcium. 2007; 42: 163-172Crossref PubMed Scopus (68) Google Scholar]). Here, we show that STIM1 directly binds to the microtubule-plus-end-tracking protein EB1 and forms EB1-dependent comet-like accumulations at the sites where polymerizing microtubule ends come in contact with the ER network. Therefore, the previously observed tubulovesicular motility of GFP-STIM1 [5Baba Y. Hayashi K. Fujii Y. Mizushima A. Watarai H. Wakamori M. Numaga T. Mori Y. Iino M. Hikida M. Kurosaki T. Coupling of STIM1 to store-operated Ca2+ entry through its constitutive and inducible movement in the endoplasmic reticulum.Proc. Natl. Acad. Sci. USA. 2006; 103: 16704-16709Crossref PubMed Scopus (259) Google Scholar] is not a motor-based movement but a traveling wave of diffusion-dependent STIM1 concentration in the ER membrane. STIM1 overexpression strongly stimulates ER extension occurring through the microtubule "tip attachment complex" (TAC) mechanism [6Waterman-Storer C.M. Salmon E.D. Endoplasmic reticulum membrane tubules are distributed by microtubules in living cells using three distinct mechanisms.Curr. Biol. 1998; 8: 798-806Abstract Full Text Full Text PDF PubMed Google Scholar, 7Waterman-Storer C.M. Gregory J. Parsons S.F. Salmon E.D. Membrane/microtubule tip attachment complexes (TACs) allow the assembly dynamics of plus ends to push and pull membranes into tubulovesicular networks in interphase Xenopus egg extracts.J. Cell Biol. 1995; 130: 1161-1169Crossref PubMed Scopus (87) Google Scholar], a process whereby an ER tubule attaches to and elongates together with the EB1-positive end of a growing microtubule. Depletion of STIM1 and EB1 decreases TAC-dependent ER protrusion, indicating that microtubule growth-dependent concentration of STIM1 in the ER membrane plays a role in ER remodeling.