Homotypic Vacuole Fusion Requires VTI11 and Is Regulated by Phosphoinositides

作     者：Sang Won Han Maria Fernanda Rodriguez-Welsh Marcela Rojas-Pierce 

作者机构：Department of Plant and Microbial Biology North Carolina State University Raleigh NC 27695 USA 

出 版 物：《Molecular Plant》 (分子植物（英文版）)

年 卷 期：2014年第7卷第6期

页      面：1026-1040页

核心收录：

学科分类：0710[理学-生物学] 071001[理学-植物学] 07[理学] 071009[理学-细胞生物学] 09[农学] 0901[农学-作物学] 090102[农学-作物遗传育种] 

基　　金：国家自然科学基金 NASA to M.R.P start-up funds from North Carolina State University the North Carolina Agricultural Research Service 

主　　题：vacuole SNARE phosphoinositides membrane fusion Wortmannin. 

摘      要：Most plant cells contain a large central vacuole that is essential to maintain cellular turgor. We report a new mutant allele of VTI11 that implicates the SNARE protein VTI11 in homotypic fusion of protein storage and lytic vacuoles. Fusion of the multiple vacuoles present in vtill mutants could be induced by treatment with Wortmannin and LY294002, which are inhibitors of Phosphatidylinositol 3-Kinase （PI3K）. We provide evidence that Phosphatidylinositol 3-Phosphate （Ptdlns（3）P） regulates vacuole fusion in vtill mutants, and that fusion of these vacuoles requires intact microtubules and actin filaments. Finally, we show that Wortmannin also induced the fusion of guard cell vacuoles in fava beans, where vacuoles are naturally fragmented after ABA-induced stomata closure. These results suggest a ubiquitous role of phosphoinositides in vacuole fusion, both during the development of the large central vacuole and during the dynamic vacuole remodeling that occurs as part of stomata movements.