SNARE-Ware: The Role of SNARE-Domain Proteins in Plant Biology

Abstract

In yeast and animal cells, members of the superfamily of Nethylmaleimide-sensitive factor adaptor protein receptor (SNARE)-domain-containing proteins are key players in vesicle-associated membrane fusion events during transport processes between individual compartments of the endomembrane system, including exocytosis and endocytosis. Compared with genomes of other eukaryotes, genomes of monocotyledonous and dicotyledonous plants encode a surprisingly high number of SNARE proteins, suggesting vital roles for this protein class in higher plant species. Although to date it remains elusive whether plant SNARE proteins function like their yeast and animal counterparts, genetic screens have recently begun to unravel the variety of biological tasks in which plant SNAREs are involved. These duties involve fundamental processes such as cytokinesis, shoot gravitropism, pathogen defense, symbiosis, and abiotic stress responses, suggesting that SNAREs contribute essentially to many facets of plant biology.

Binding of SEC11 Indicates Its Role in SNARE Recycling after Vesicle Fusion and Identifies Two Pathways for Vesicular Traffic to the Plasma Membrane

“…The Arabidopsis Qa-SNAREs SYP121 (=SYR1/PEN1) and SYP122 exhibit high sequence homology and overlapping functions, and both are present at the plasma membrane of cells throughout the plant (Lipka et al, 2007;Bassham and Blatt, 2008). Along with the Qa-SNARE SYP132, which is constitutively expressed and present at low levels (Enami et al, 2009), these proteins mediate secretory vesicle traffic, contributing to cellular homeostasis, expansion, and growth (Blatt, 2000;Shope et al, 2003;Campanoni and Blatt, 2007).…”

“…SNAREs drive the fusion of vesicle and target membranes and enable the transfer of soluble and membrane-associated cargos in a highly regulated manner (Pratelli et al, 2004;Jahn and Scheller, 2006;Lipka et al, 2007;Bassham and Blatt, 2008). In plant cells, SNARE-mediated vesicle traffic delivers wall materials and membrane to the cell surface, making essential contributions to homeostasis, cell expansion, and growth (Blatt, 2000;Shope et al, 2003;Campanoni and Blatt, 2007).…”

Vesicle Trafficking during Somatic Cytokinesis

“…Vesicle fusion is accomplished through the action of SNARE proteins (for review, see Lipka et al, 2007), tethering factors (Rab GTPases; for review, see Zerial and McBride, 2001;Molendijk et al, 2004), and presumably aided by components of the exocyst complex (Segui-Simarro et al, 2004), although, to date, mutants defective in subunits of this complex have only been implicated in polar growth (Cole et al, 2005;Wen et al, 2005;Synek et al, 2006;Lavy et al, 2007). The darkstained vesicles were also found in the vicinity of the Golgi apparatus, and it was concluded that they were Golgi derived.…”

Requirement of Vesicle-Associated Membrane Protein 721 and 722 for Sustained Growth during Immune Responses in Arabidopsis

“…It is generally accepted that members of the soluble N-ethylmaleimide sensitive factor attachment protein receptor (SNARE) superfamily are key factors to drive vesicle fusion events in eukaryotes including yeasts, animals and plants (Jahn and Scheller, 2006). Plant genomes contain a larger number of SNARE genes than yeast and animals, implying a higher degree of sub-functionalization as illustrated by the engagement of distinct SNARE genes in different biological processes such as cytokinesis, gravitropism and disease resistance (Lipka et al, 2007;Sanderfoot, 2007).…”