D'Hondt K, Van Damme J, Van Den Bossche C, Leejeerajumnean S, De Rycke R, Derksen J, Vandekerckhove J, Krebbers E
Plant Genetic Systems, Gent, Belgium.
Plant Physiol. 1993 Jun;102(2):425-33. doi: 10.1104/pp.102.2.425.
To investigate the possible roles of the Arabidopsis thaliana 2S albumin propeptides with respect to sorting, processing, and stability of the protein in plant cells, five gene constructions deleting or modifying the propeptides were made based on one of the genes encoding the Arabidopsis 2S albumin. These constructions were introduced into tobacco (Nicotiana tabacum) plants. Using subcellular fractionation and immunocytochemistry on ripe seeds, it was demonstrated that none of the propeptides was necessary for the sorting of the protein. Detailed protein-chemical analysis of the mature gene products indicated that, for all of the modified 2S albumin precursors made, the proteins were stably folded and correctly processed. However, the latter is less efficient when the internal fragment between the small and the large subunit is missing or when this internal fragment is changed. In an attempt to establish a rapid assay system for modified 2S albumin precursors, yeast cells were transformed with the same gene constructs. It was demonstrated that the processing machinery in yeast cells differs from that in plants, and, in a perhaps related observation, differences in stability of a particular modified protein were observed.
为了研究拟南芥2S清蛋白前肽在植物细胞中对蛋白质分选、加工和稳定性的可能作用，基于其中一个编码拟南芥2S清蛋白的基因构建了5个缺失或修饰前肽的基因结构。将这些结构导入烟草（Nicotiana tabacum）植株。通过对成熟种子进行亚细胞分级分离和免疫细胞化学分析，结果表明没有一个前肽对于蛋白质的分选是必需的。对成熟基因产物进行的详细蛋白质化学分析表明，对于所有构建的修饰2S清蛋白前体，蛋白质都能稳定折叠并正确加工。然而，当小亚基和大亚基之间的内部片段缺失或该内部片段发生改变时，加工效率会降低。为了建立一种针对修饰2S清蛋白前体的快速检测系统，用相同的基因构建体转化酵母细胞。结果表明酵母细胞中的加工机制与植物中的不同，并且，在一个可能相关的观察中，观察到了特定修饰蛋白稳定性的差异。
