期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：2020
卷号：117
期号：18
页码：9884-9895
DOI：10.1073/pnas.1919820117
出版社：The National Academy of Sciences of the United States of America
摘要：The factors and mechanisms involved in vacuolar transport in plants, and in particular those directing vesicles to their target endomembrane compartment, remain largely unknown. To identify components of the vacuolar trafficking machinery, we searched for Arabidopsis modified transport to the vacuole ( mtv ) mutants that abnormally secrete the synthetic vacuolar cargo VAC2. We report here on the identification of 17 mtv mutations, corresponding to mutant alleles of MTV2/VSR4 , MTV3/PTEN2A MTV7/EREL1 , MTV8/ARFC1 , MTV9/PUF2 , MTV10/VPS3 , MTV11/VPS15 , MTV12/GRV2 , MTV14/GFS10 , MTV15/BET11 , MTV16/VPS51 , MTV17/VPS54 , and MTV18/VSR1 . Eight of the MTV proteins localize at the interface between the trans -Golgi network (TGN) and the multivesicular bodies (MVBs), supporting that the trafficking step between these compartments is essential for segregating vacuolar proteins from those destined for secretion. Importantly, the GARP tethering complex subunits MTV16/VPS51 and MTV17/VPS54 were found at endoplasmic reticulum (ER)- and microtubule-associated compartments (EMACs). Moreover, MTV16/VPS51 interacts with the motor domain of kinesins, suggesting that, in addition to tethering vesicles, the GARP complex may regulate the motors that transport them. Our findings unveil a previously uncharacterized compartment of the plant vacuolar trafficking pathway and support a role for microtubules and kinesins in GARP-dependent transport of soluble vacuolar cargo in plants.
