The Engineering Research Institute of Agriculture and Forestry, Ludong University, Yantai, 264025, China; School of Life Sciences, Centre for Cell and Developmental Biology and State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China.
School of Life Sciences, Centre for Cell and Developmental Biology and State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China; Shenzhen Research Institute, The Chinese University of Hong Kong, Shenzhen 518057, China.
J Plant Physiol. 2023 Dec;291:154137. doi: 10.1016/j.jplph.2023.154137. Epub 2023 Nov 10.
Vacuolar sorting is critically important in plants as it regulates the mobilization of proteins and plays a major role in important agricultural traits like yield and seed protein content. Vacuolar sorting receptors (VSRs) are integral membrane proteins that mediate protein trafficking from the Golgi apparatus to the vacuole via the intermediate membrane-bound prevacuolar compartment (PVC)/multivesicular body (MVB). VSR proteins, such as an 80 kD (BP-80) from pea, also serve as markers for PVC/MVB. Dissecting VSR-mediated protein trafficking pathways may provide ways to enhance agronomic traits and crop yield. Green fluorescence protein (GFP) fusions with the seven Arabidopsis (Arabidopsis thaliana) VSRs were previously shown to localize to PVCs in transgenic tobacco BY-2 cells. The Rice (Oryza sativa) genome contains seven VSRs (OsVSR1-7), but little is known about their subcellular localizations. Here we studied the subcellular localization of OsVSR1-7 b y using a reporter approach, in which GFP-OsVSR1-7 fusions containing the transmembrane domain (TMD) and cytoplasmic tail (CT) of individual OsVSR were expressed in the protoplasts of rice, transgenic tobacco BY-2 cells and transgenic rice plants. Immunofluorescent labelling studies and confocal laser scanning microscope observation demonstrated that the seven OsVSRs are localized to PVCs and form ring-like structures upon wortmannin treatment. Therefore, we have verified the subcellular localization of OsVSR1-7 in this study. The OsVSRs tagged with GFP can serve as PVCs/MVBs markers in rice for the future studies.
液泡分拣在植物中至关重要，因为它调节蛋白质的动员，并在产量和种子蛋白质含量等重要农业性状中发挥主要作用。液泡分拣受体 (VSR) 是一种完整的膜蛋白，通过中间的膜结合前液泡区 (PVC)/多泡体 (MVB) 将蛋白质从高尔基体运输到液泡。VSR 蛋白，如豌豆的 80kD (BP-80)，也可作为 PVC/MVB 的标志物。解析 VSR 介导的蛋白质运输途径可能提供增强农业性状和作物产量的方法。先前已显示 GFP 与七个拟南芥 (Arabidopsis thaliana) VSR 的融合蛋白在转基因烟草 BY-2 细胞中定位于 PVC。水稻 (Oryza sativa) 基因组包含七个 VSR (OsVSR1-7)，但对它们的亚细胞定位知之甚少。在这里，我们通过报告基因方法研究了 OsVSR1-7 的亚细胞定位，其中包含单个 OsVSR 的跨膜域 (TMD) 和细胞质尾巴 (CT) 的 GFP-OsVSR1-7 融合蛋白在水稻原生质体、转基因烟草 BY-2 细胞和转基因水稻植株中表达。免疫荧光标记研究和共焦激光扫描显微镜观察表明，这七个 OsVSR 定位于 PVC，并在wortmannin 处理后形成环状结构。因此，我们在本研究中验证了 OsVSR1-7 的亚细胞定位。标记 GFP 的 OsVSR 可作为水稻中 PVCs/MVBs 的标志物，用于未来的研究。
