AtSYP51/52 Functions Diverge in the Post-Golgi Traffic and Differently Affect Vacuolar Sorting

• Published in: Molecular plant 2013-05, Vol.6 (3), p.916-930
• Main Authors: De Benedictis, Maria, Bleve, Gianluca, Faraco, Marianna, Stigliano, Egidio, Grieco, Francesco, Piro, Gabriella, Dalessandro, Giuseppe, Di Sansebastiano, Gian Pietro
• Format: Article
• Language: English
• Subjects: Arabidopsis - cytology; Arabidopsis - metabolism; Arabidopsis Proteins - metabolism; Blotting, Western; Cell Compartmentation; Endocytosis; endosome; Exocytosis; Genetic Complementation Test; Golgi; Golgi Apparatus - metabolism; Green Fluorescent Proteins - metabolism; i-SNARE; plant endomembranes; Plants, Genetically Modified; Protein Transport; protoplast; Protoplasts - metabolism; Qa-SNARE Proteins - metabolism; Recombinant Fusion Proteins - metabolism; Recombination, Genetic - genetics; Saccharomyces cerevisiae - growth & development; Saccharomyces cerevisiae - metabolism; Saccharomyces cerevisiae Proteins - metabolism; SNARE; SNARE蛋白; Solubility; TGN; tonoplast; Transformation, Genetic; vacuole; Vacuoles - metabolism; 交通; 分泌途径; 发散; 基因编码; 排序; 敏感因子; 液泡
• ISSN: 1674-2052; 1752-9867
• DOI: 10.1093/mp/sss117

Plant sensitive factor attachment protein receptors （SNAREs） encoded by genes of the same sub-family are generally considered as redundant in promoting vesicle-associated membrane fusion events. Nonetheless, the application of innovative experimental approaches highlighted that members of the same gene sub-family often have different functional specificities. In this work, two closely related Qc-SNAREs--the AtSYP51 and the AtSYP52--are compared in their ability to influence different secretory pathways. Their role in the vesicle sorting to the central vacuole has been revised and they were found to have a novel inhibitory function. When transiently overexpressed, the SYP51 and the SYP52 distributed between the TGN and the tonoplast. Our data demonstrate that these SYPs （syntaxin of plants） act as t-SNARE when present on the membrane of TGN/PVC, whereas they behave as inhibitory or interfering SNAREs （i-SNAREs） when they accumulate on the tonoplast. Moreover, the performed functional analysis indicated that the AtSYP51 and the AtSYP52 roles differ in the traffic to the vacuole. The findings are a novel contribution to the functional characterization of plant SNAREs that reveals additional non-fusogenic roles.