The SNARE Proteins (In Plants) Beyond the Nobel Prize

Abstract

Volume 2 • Issue 2 • 1000e122 J Plant Biochem Physiol ISSN: 2329-9029 JPBP, an open access journal SNAREs (N-ethylmaleimide-sensitive factor adaptor protein receptors) are small polypeptides characterized by a specific domain called SNARE motif. This can form a coiled-coil structure and interacts with other SNARE motifs via hetero-oligomeric interactions to form highly stable protein-protein interactions. The derived complex is called SNARE-complex and allows membrane fusion. SNAREs also interact with several proteins acting as regulators of this complex formation. Their indubitable importance was certified by the Nobel Prize 2013 for Medicine, awarded to the scientist who clarified the way they interact, James E. Rothman. Nobel Prize was shared with the other two scientists contributing to the description of vesicle traffic, Randy W. Schekman, and Thomas C. Südhof, but SNAREs certainly have central role in the determination of traffic specificity. Recently the model that won the Nobel was enormously enriched by further discoveries, about SNAREs in particular. In fact SNAREs stoichiometry reveals that they are more abundant than required for membrane traffic. The regulation of vesicle traffic certainly remains the most important role of these proteins but in doing so, SNAREs have a clear influence on several signalling pathways. SNAREs take part to receptors turnover through endocytosis and exocytosis but they can also directly gate channels and interact with membrane proteins potentially involved in signalling processes. Phosphorylation of SNAREs upon elicitation and hormonal control are known. I will try here to briefly review these diversified functions to have a complete overview of SNAREs importance. Certainly membrane fusion is mediated by interactions between complementary SNAREs distributed on the vesicles and the target membrane. This complex is formed by three or four types of distinctive SNAREs contributing to the formation of a four-helix bundle [1]. On the base of their localization (Functional classification) SNAREs have been classified into vesicle-associated (v-SNAREs) and target membrane– associated SNAREs (t-SNAREs) [2]. This classification does not take into account the role of SNAREs in the context of homotypic fusion events or progressive anterograde traffic.