A plant manganese superoxide dismutase is efficiently imported and correctly processed by yeast mitochondria.
A plant manganese superoxide dismutase is efficiently imported and correctly processed by yeast mitochondria.
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DOI：
10.1073/pnas.86.9.3237
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发表时间：
1989-05
影响因子：
11.1
通讯作者：
Chris Bowler;Thiery Alliotte;M. Bulcke;G. Bauw;J. Vandekerckhove;M. V. Montagu;Dirk Inzé
中科院分区：
文献类型：
--
作者：
Chris Bowler;Thiery Alliotte;M. Bulcke;G. Bauw;J. Vandekerckhove;M. V. Montagu;Dirk Inzé
在植物烟草（Nicotiana plumbaginifolia）中，锰超氧化物歧化酶（MnSOD）作为前蛋白在细胞质中合成，随后易位至线粒体基质，并伴随相应的NH 2-末端前导序列的裂解。为了确定植物酶是否可以取代大肠杆菌和酵母的内源性SOD活性，在适当的载体中构建了前蛋白和成熟MnSOD的表达。这些被引入到SOD缺陷菌株的互补研究。在大肠在大肠杆菌中，这两种形式的蛋白质都被证明是有活性的，并且能够在不同程度上补充SOD缺乏。在缺乏线粒体MnSOD的酵母菌株中表达前蛋白导致野生型生长的恢复，只有当植物蛋白被靶向线粒体时才有可能。随后的研究表明，蛋白质被加工，前导序列在与植物线粒体肽酶识别的相同位置被切割。因此，介导线粒体输入的组件似乎是高度保守的植物和酵母之间。
In the plant Nicotiana plumbaginifolia, manganese superoxide dismutase (MnSOD) is synthesized in the cytoplasm as a preprotein and is subsequently translocated to the mitochondrial matrix with corresponding cleavage of an NH2-terminal leader sequence. To determine whether the plant enzyme could replace the endogenous SOD activities of Escherichia coli and yeast, constructions have been made in appropriate vectors for expression of the preprotein and the mature MnSOD. These were introduced into SOD-deficient strains for complementation studies. In E. coli, both forms of the protein were shown to be active and able to complement SOD deficiency to different degrees. Expression of the preprotein in a yeast strain lacking a mitochondrial MnSOD resulted in a restoration of wild-type growth, only possible if the plant protein was being targeted to the mitochondria. Subsequent studies revealed that the protein was processed and that the leader sequence was cleaved at the identical position as recognized by the mitochondrial peptidase of plants. The components mediating mitochondrial import thus appear to be highly conserved between plants and yeast.