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

Abstract

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 ¢lament-like structures. Finally, puri¢ed recombinant syntaxin 4 but not syntaxin 2 or 3 cosedimented with actin ¢laments 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. ß 2002 Published by Elsevier Science B.V. on behalf of the Federation of European Biochemical Societies.

Cholesterol transport from late endosomes to the Golgi regulates t-SNARE trafficking, assembly, and function

“…For instance, AnxA6 could compete with SNARE proteins in PM microdomains through interacting and/or rearranging the cortical actin cytoskeleton (Monastyrskaya et al , 2009b), potentially impairing the formation of syntaxin-4–actin protein complexes (Band et al , 2002). As has been proposed for other annexins in this framework of molecular rearrangements, elevated AnxA6 levels at the PM could potentially alter phospholipid asymmetry, which could then modify the affinity/efficiency of SNAREs to bind and form clusters.…”

Rab11 GTPase-Regulated Membrane Trafficking Is Crucial for Tip-Focused Pollen Tube Growth in Tobacco

“…Members of the Rab11 family are also known to play prominent roles in the recycling of receptor proteins from endosomes directly to the plasma membrane or through the Golgi network (Ullrich et al, 1996;Chen et al, 1998;Schlierf et al, 2000;Wilcke et al, 2000;Band et al, 2002;Cheng et al, 2002;Volpicelli et al, 2002;Molendijk et al, 2004). The temporal pattern of FM4-64 uptake into pollen tubes, initial internalization and labeling of small organelles, followed by signal redistribution to a pronounced accumulation in the apical clear zone showed that endocytic membrane recycling also actively contributes to the apical collection of vesicles (Parton et al, 2001;Camacho and Malho, 2003).…”

“…Some Rab11 GTPases in animals and yeast are known to play important roles in membrane recycling, in particular the transport of receptor proteins between endosomes, trans-Golgi network, and the plasma membrane (Ullrich et al, 1996;Schlierf et al, 2000;Wilcke et al, 2000;Band et al, 2002;Hales et al, 2002;Volpicelli et al, 2002). They have also been associated with functions in various steps of exocytosis (Benli et al, 1996;Jedd et al, 1997;Chen et al, 1998;Cheng et al, 2002;Ortiz et al, 2002) and phagocytosis (Cox et al, 2000) or in the mobility of vesicles along actin bundles (Schott et al, 1999;Lapierre et al, 2001;Band et al, 2002;Hales et al, 2002;Volpicelli et al, 2002). In plants, green fluorescent protein (GFP)-tagged Rab11 homologs from pea (Pisum sativum), Pra-2 and Pra-3, have been localized to Golgi bodies and endosomes, respectively, when expressed in tobacco cells (Inaba et al, 2002), whereas GFP-Pra2 localized to the endoplasmic reticulum when expressed in Arabidopsis (Kang et al, 2001).…”

Role of Insulin-dependent Cortical Fodrin/Spectrin Remodeling in Glucose Transporter 4 Translocation in Rat Adipocytes

“…There have been a limited number of studies suggesting a link between components of the actin cytoskeleton network and the soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) proteins (for review, see Hong, 2005) that mediate vesicle fusion in the exocytic pro-cess (Nakano et al, 2001;Band et al, 2002;Fan and Beck, 2004;Low et al, 2006). GSVs contain VAMP2 as their vesicle SNARE, which interacts with syntaxin 4 (Syn4) at the plasma membrane to mediate vesicle fusion and presents GLUT4 to the extracellular milieu where it can function (for review, see Grusovin and Macaulay, 2003).…”

“…The cortical cytoskeleton network has numerous protein components in addition to actin and tubulin (dos Remedios et al, 2003;Winder and Ayscough, 2005), including spectrin family members, which have been suggested to serve membrane-sorting tasks (Beck and Nelson, 1996;Brown and Breton, 2000;Broderick and Winder, 2005). We report here that fodrins, also called nonerythroid spectrins, are abundantly expressed in adipocytes where they serve a role in GLUT4 translocation.There have been a limited number of studies suggesting a link between components of the actin cytoskeleton network and the soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) cess (Nakano et al, 2001;Band et al, 2002;Fan and Beck, 2004;Low et al, 2006). GSVs contain VAMP2 as their vesicle SNARE, which interacts with syntaxin 4 (Syn4) at the plasma membrane to mediate vesicle fusion and presents GLUT4 to the extracellular milieu where it can function (for review, see Grusovin and Macaulay, 2003).…”