EXPRESSION OF THE WILD-TYPE AND MUTATED VACUOLAR STORAGE PROTEIN PHASEOLIN IN XENOPUS OOCYTES REVEALS RELATIONSHIPS BETWEEN ASSEMBLY AND INTRACELLULAR-TRANSPORT
EXPRESSION OF THE WILD-TYPE AND MUTATED VACUOLAR STORAGE PROTEIN PHASEOLIN IN XENOPUS OOCYTES REVEALS RELATIONSHIPS BETWEEN ASSEMBLY AND INTRACELLULAR-TRANSPORT
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DOI：
10.1111/j.1432-1033.1991.tb16456.x
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发表时间：
1991-12-18
期刊：
影响因子：
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通讯作者：
VITALE, A
中科院分区：
文献类型：
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作者：
CERIOTTI, A;PEDRAZZINI, E;VITALE, A
以注射RNA的非洲爪哇卵母细胞为材料，研究了亚基组装在豆类贮藏蛋白小菜豆蛋白胞内转运中的作用。我们发现，小菜豆蛋白的组装依赖于蛋白质的合成水平，并且是细胞内运输出内质网所必需的。我们还发现，组装好的小红豆素的一部分永久地保留在内质网后的隔室中。C末端α-螺旋结构域的缺失完全阻止了体内组装，但不能阻止内质网滞留。这表明该结构域对于三聚化是必需的，但对于未组装的亚基与内质网组件的相互作用则不是必需的。截短型小菜豆在体内具有较高的稳定性。这些发现对通过基因工程改善菜豆的营养价值的可能性的潜在影响进行了讨论。
The role played by subunit assembly in the intracellular transport of the bean storage protein phaseolin, a soluble trimeric glycoprotein, was investigated using Xenopus oocytes injected with RNA. We show that phaseolin assembly is dependent upon the level of synthesis of the protein and is required for intracellular transport out of the endoplasmic reticulum. We also show that a fraction of the assembled phaseolin is permanently retained in a post-endoplasmic reticulum compartment. Deletion of the C-terminal alpha-helical domain fully prevents in vivo assembly but not endoplasmic reticulum retention. This indicates that this domain is necessary for trimerization but not for interactions of unassembled subunits with endoplasmic reticulum components. The truncated phaseolin has high in vivo stability. The potential implications of these findings on the possibility to improve the nutritional value of phaseolin through genetic engineering are discussed.