Endogenous plasma membrane t‐SNARE syntaxin 4 is present in rab11 positive endosomal membranes and associates with cortical actin cytoskeleton

FEBS Letters

Vartiainen, Maria K³  Band, Arja M¹  Welti, Saara¹  Lappalainen, Pekka³  Olkkonen, Vesa M²  Ali, Heidi¹  Kuismanen, Esa¹ 

[1] Department of Biosciences, Division of Biochemistry, Viikki Biocenter, University of Helsinki, P.O. Box 56, Viikinkaari 5, 00014 Helsinki, Finland;Department of Molecular Medicine, National Public Health Institute (KTL), Biomedicum, P.O. Box 104, 00251 Helsinki, Finland;Institute of Biotechnology, Viikki Biocenter, Viikinkaari 5, 00014 Helsinki, Finland

关键词: Syntaxin 4;    Actin;    rab11;    ADF;    actin monomer binding protein cofilin/actin depolymerizing factor;    NEM;    N-ethylmaleimide;    EEA1;    early endosome antigen 1;    NRK;    normal rat kidney;    NSF;    N-ethylmaleimide-sensitive fusion factor;    SNAP;    soluble NSF attachment protein;    SNARE;    SNAP receptor;    TGN;    trans-Golgi network;   

DOI  :  10.1016/S0014-5793(02)03605-0

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Membrane fusion requires the formation of a complex between a vesicle protein (v-SNARE) and the target membrane proteins (t-SNAREs). Syntaxin 4 is a t-SNARE that, according to previous overexpression studies, is predominantly localized at the plasma membrane. In the present study endogenous syntaxin 4 was found in intracellular vesicular structures in addition to regions of the plasma membrane. In these vesicular structures syntaxin 4 colocalized with rab11, a marker of recycling endosomes. Furthermore, syntaxin 4 colocalized with actin at the dynamic regions of the plasma membrane. Treatment with N-ethylmaleimide, the membrane transport inhibitor, caused an increased accumulation of syntaxin 4/rab11 positive vesicles in actin filament-like structures. Finally, purified recombinant syntaxin 4 but not syntaxin 2 or 3 cosedimented with actin filaments in vitro, suggesting direct interaction between these two proteins. Taken together, these data suggest that syntaxin 4 regulates secretion at the actin-rich areas of the plasma membrane and may be recycled through rab11 positive intracellular membranes.

【 授权许可】

Unknown