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Endogenous plasma membrane t‐SNARE syntaxin 4 is present in rab11 positive endosomal membranes and associates with cortical actin cytoskeleton
Author(s) -
Band Arja M,
Ali Heidi,
Vartiainen Maria K,
Welti Saara,
Lappalainen Pekka,
Olkkonen Vesa M,
Kuismanen Esa
Publication year - 2002
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/s0014-5793(02)03605-0
Subject(s) - syntaxin 3 , microbiology and biotechnology , syntaxin , endosome , snare complex , lipid bilayer fusion , actin cytoskeleton , actin , exocytosis , intracellular , chemistry , vesicle , biology , membrane , cytoskeleton , biochemistry , cell
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.