Mutant alcohol dehydrogenase (ADH III) presequences that affect both in vitro mitochondrial import and in vitro processing by the matrix protease.
Mutant alcohol dehydrogenase (ADH III) presequences that affect both in vitro mitochondrial import and in vitro processing by the matrix protease.
复制标题
突变的乙醇脱氢酶 (ADH III) 前序列会影响体外线粒体输入和基质蛋白酶的体外加工。
DOI：
10.1128/mcb.10.6.2801-2808.1990
复制
发表时间：
1990
影响因子：
5.3
通讯作者：
Young,ET
中科院分区：
文献类型：
--
作者：
Mooney,DT;Pilgrim,DB;Young,ET
Point mutations in the presequence of the mitochondrial alcohol dehydrogerase isoenzyme (ADH III) have been shown to affect either the import of the precursor protein into yeast mitochondria in vivo or its processing within the organelle. In the present work, the behavior of these mutants during in vitro import into isolated mitochondria was investigated. All point mutants tested were imported with a slower initial rate than that of the wild-type precursor. This defect was corrected when the precursors were treated with urea prior to import. Once imported, the extent of processing to the mature form of mutant precursors varied greatly and correlated well with the defects observed in vivo. This result was not affected by prior urea treatment. When matrix extracts enriched for the processing protease were used, this defect was shown to be due to failure of the protease to efficiently recognize or cleave the presequence, rather than to a lack of access to the precursor. The rate of import of two ADH III precursors bearing internal deletions in the leader sequence was similar to those of the point mutants, whereas a deletion leading to the removal of the 15 amino-terminal amino acids was poorly imported. The mature amino terminus of wild-type ADH III was determined to be Gln-25. Mutant m01 (Ser-26 to Phe), which reduced the efficiency of cleavage in vitro by 80%, was cleaved at the correct site.
