Vacuolar Processing Enzyme plays an Essential Role in the Crystalline Structure of Glutelin in Rice Seed
Vacuolar Processing Enzyme plays an Essential Role in the Crystalline Structure of Glutelin in Rice Seed
复制标题
DOI：
10.1093/pcp/pcp165
复制
发表时间：
2010-01-01
影响因子：
4.9
通讯作者：
Satoh, Hikaru
中科院分区：
文献类型：
--
作者：
Kumamaru, Toshihiro;Uemura, Yuji;Satoh, Hikaru
为了确定调节谷蛋白原加工的基因的功能，我们对glup 3突变体进行了分析，该突变体积累了过量的谷蛋白原，缺乏液泡加工酶（VPE）。与野生型相比，glup 3品系发育种子中的VPE活性显著降低。Glup 3突变体中VPE基因的DNA测序揭示了编码区内的氨基酸取代或终止密码子的出现。显微镜下观察表明，-球蛋白和proglutelin均匀分布在glup 3蛋白质存储泡（PSV），和glup 3 PSV缺乏典型的野生型PSV的晶格结构。这表明VPE对水稻谷蛋白前体的加工对于PSV的结构和贮藏蛋白的区室化是必不可少的。还观察到glup 3幼苗生长迟缓，表明谷蛋白原的处理影响早期幼苗发育。这些研究结果表明，存储谷蛋白在其成熟形式的晶体结构在PSV是必需的快速使用谷蛋白作为氨基酸的来源，在早期幼苗发育。总之，VPE在PSV中蛋白质晶体结构的形成中起着重要作用。
To identify the function of genes that regulate the processing of proglutelin, we performed an analysis of glup3 mutants, which accumulates excess amounts of proglutelin and lack the vacuolar processing enzyme (VPE). VPE activity in developing seeds from glup3 lines was reduced remarkably compared with the wild type. DNA sequencing of the VPE gene in glup3 mutants revealed either amino acid substitutions or the appearance of a stop codon within the coding region. Microscopic observations showed that -globulin and proglutelin were distributed homogeneously within glup3 protein storage vacuoles (PSVs), and that glup3 PSVs lacked the crystalline lattice structure typical of wild-type PSVs. This suggests that the processing of proglutelin by VPE in rice is essential for proper PSV structure and compartmentalization of storage proteins. Growth retardation in glup3 seedlings was also observed, indicating that the processing of proglutelin influences early seedling development. These findings indicate that storage of glutelin in its mature form as a crystalline structure in PSVs is required for the rapid use of glutelin as a source of amino acids during early seedling development. In conclusion, VPE plays an important role in the formation of protein crystalline structures in PSVs.