A C-terminal sequence of soybean β-conglycinin α′ subunit acts as a vacuolar sorting determinant in seed cells
A C-terminal sequence of soybean β-conglycinin α′ subunit acts as a vacuolar sorting determinant in seed cells
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DOI：
10.1046/j.1365-313x.2003.01754.x
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发表时间：
2003-06-01
期刊：
影响因子：
7.2
通讯作者：
Utsumi, S
中科院分区：
文献类型：
--
作者：
Nishizawa, K;Maruyama, N;Utsumi, S
在成熟的种子细胞中，许多新合成的蛋白质通过种子细胞特有的囊泡转运至蛋白质储存液泡（PSV）。大多数这些蛋白质中的液泡分选决定簇 (VSD) 已使用除种子细胞外的叶、根或悬浮培养细胞测定。在这项研究中，我们使用拟南芥和大豆种子检查了 β-伴大豆球蛋白（7S 球蛋白）的 α' 亚基的 VSD，β-伴大豆球蛋白是大豆的主要种子储存蛋白之一。野生型α'被转运至转基因拟南芥种子细胞中的PSV基质，并形成类晶体结构。一些野生型 α' 也被转运到 PSV 中的半透明区室 (TLC)，推测是球状区室。然而，缺少 C 端 10 个氨基酸的衍生物并未被转运至 PSV 基质，而是被分泌到细胞外，尽管一部分也被转运至 TLC。 α' 的 C 末端区域足以将绿色荧光蛋白 (GFP) 转运至 PSV 基质。这些表明 alpha' 包含两个 VSD：一个存在于 C 端 10 个氨基酸中，用于 PSV 矩阵；另一个存在于 C 端 10 个氨基酸中，用于 PSV 矩阵；另一个用于 TLC（球状室）。我们通过使用瞬时表达系统进一步验证了 C 端 10 个氨基酸足以将 GFP 转运至大豆种子细胞中的 PSV 基质。
In maturing seed cells, many newly synthesized proteins are transported to the protein storage vacuoles (PSVs) via vesicles unique to seed cells. Vacuolar sorting determinants (VSDs) in most of these proteins have been determined using leaf, root or suspension-cultured cells apart from seed cells. In this study, we examined the VSD of the alpha' subunit of beta-conglycinin (7S globulin), one of the major seed storage proteins of soybean, using Arabidopsis and soybean seeds. The wild-type alpha' was transported to the matrix of the PSVs in seed cells of transgenic Arabidopsis , and it formed crystalloid-like structures. Some of the wild-type alpha' was also transported to the translucent compartments (TLCs) in the PSV presumed to be the globoid compartments. However, a derivative lacking the C-terminal 10 amino acids was not transported to the PSV matrix, and was secreted out of the cells, although a portion was also transported to the TLCs. The C-terminal region of alpha' was sufficient to transport a green fluorescent protein (GFP) to the PSV matrix. These indicate that alpha' contains two VSDs: one is present in the C-terminal 10 amino acids and is for the PSV matrix; and the other is for the TLC (the globoid compartment). We further verified that the C-terminal 10 amino acids were sufficient to transport GFP to the PSV matrix in soybean seed cells by using a transient expression system.