Arabidopsis VPS35, a retromer component, is required for vacuolar protein sorting and involved in plant growth and leaf senescence
Arabidopsis VPS35, a retromer component, is required for vacuolar protein sorting and involved in plant growth and leaf senescence
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DOI：
10.1093/pcp/pcn006
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发表时间：
2008-02-01
影响因子：
4.9
通讯作者：
Hara-Nishimura, Ikuko
中科院分区：
文献类型：
--
作者：
Yamazaki, Misako;Shimada, Tomoo;Hara-Nishimura, Ikuko
逆行体复合物负责逆行运输，其与包括液泡蛋白分选的分泌途径中的顺行运输相协调。酵母VPS 35是retromer复合物的组分，其对于识别特定货物分子是必需的。VPS 35在高等生物液泡蛋白分选中的生理功能尚未确定。拟南芥有三个VPS 35同源物，命名为VPS 35 a、VPS 35 b和VPS 35 c。我们分离了四个vps 35突变体（vps 35 a-1，vps 35 b-1，vps 35 b-2和vps 35 c-1），然后产生四个双突变体和一个三突变体。vps 35 a-1 vps 35 c-1没有表现出异常表型。另一方面，vps 35 b-1 vps 35 c-1和三突变体（vps 35 a-1 vps 35 b-2 vps 35 c-1）表现出严重的表型：矮化，早期叶片衰老和蛋白质储存液泡（PSV）的碎片。此外，这些突变体通过将储存蛋白分泌出细胞来错误分选储存蛋白，并且比野生型积累更高水平的液泡分选受体（VSR）。VPS 35定位于前液泡室（PVC），其中一些含有VSR。VPS 35与VPS 29/MAG 1（逆转录聚合物复合物的另一组分）免疫沉淀。我们的研究结果表明，VPS 35，主要是VPS 35 b，参与分选蛋白质PSV在种子中，可能通过回收VSR从PVC到高尔基复合体，也参与植物生长和衰老的营养器官。
The retromer complex is responsible for retrograde transport, which is coordinated with anterograde transport in the secretory pathway including vacuolar protein sorting. Yeast VPS35 is a component of the retromer complex that is essential for recognition of specific cargo molecules. The physiological function of VPS35 has not been determined in vacuolar protein sorting in higher organisms. Arabidopsis thaliana has three VPS35 homologs designated VPS35a, VPS35b and VPS35c. We isolated four vps35 mutants (vps35a-1, vps35b-1, vps35b-2 and vps35c-1) and then generated four double mutants and one triple mutant. vps35a-1 vps35c-1 exhibited no unusual phenotypes. On the other hand, vps35b-1 vps35c-1 and the triple mutant (vps35a-1 vps35b-2 vps35c-1) exhibited severe phenotypes: dwarfism, early leaf senescence and fragmentation of protein storage vacuoles (PSVs). In addition, these mutants mis-sorted storage proteins by secreting them out of the cells and accumulated a higher level of vacuolar sorting receptor (VSR) than the wild type. VPS35 was localized in pre-vacuolar compartments (PVCs), some of which contained VSR. VPS35 was immunoprecipitated with VPS29/MAG1, another component of the retromer complex. Our findings suggest that VPS35, mainly VPS35b, is involved in sorting proteins to PSVs in seeds, possibly by recycling VSR from PVCs to the Golgi complex, and is also involved in plant growth and senescence in vegetative organs.