STIM1 is a MT-plus-end-tracking protein involved in remodeling of the ER.
Curr Biol
; 18(3): 177-82, 2008 Feb 12.
Article
em En
| MEDLINE
| ID: mdl-18249114
ABSTRACT
Stromal interaction molecule 1 (STIM1) is a transmembrane protein that is essential for store-operated Ca(2+) entry, a process of extracellular Ca(2+) influx in response to the depletion of Ca(2+) stores in the endoplasmic reticulum (ER) (reviewed in [1-4]). STIM1 localizes predominantly to the ER; upon Ca(2+) release from the ER, STIM1 translocates to the ER-plasma membrane junctions and activates Ca(2+) channels (reviewed in [1-4]). 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 [5] 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 [6, 7], 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.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Retículo Endoplasmático
/
Proteínas de Membrana
/
Microtúbulos
/
Proteínas de Neoplasias
Limite:
Humans
Idioma:
En
Ano de publicação:
2008
Tipo de documento:
Article