Primary structure requirements for correct sorting of the yeast mitochondrial protein ADH III to the yeast mitochondrial matrix space.
Primary structure requirements for correct sorting of the yeast mitochondrial protein ADH III to the yeast mitochondrial matrix space.
复制标题
将酵母线粒体蛋白 ADH III 正确分类到酵母线粒体基质空间的一级结构要求。
DOI：
10.1128/mcb.7.1.294-304.1987
复制
发表时间：
1987
影响因子：
5.3
通讯作者：
Young,ET
中科院分区：
文献类型：
--
作者：
Pilgrim,D;Young,ET
Alcohol dehydrogenase isoenzyme III (ADH III) inSaccharomyces cerevisiae, the product of theADH3gene, is located in the mitochondrial matrix. The ADH III protein was synthesized as a larger precursor in vitro when the gene was transcribed with the SP6 promoter and translated with a reticulocyte lysate. A precursor of the same size was detected when radioactively pulse-labeled proteins were immunoprecipitated with anti-ADH antibody. This precursor was rapidly processed to the mature form in vivo with a half-time of less than 3 min. The processing was blocked if the mitochondria were uncoupled with carbonyl cyanidem-chlorophenylhydrazone. Mutant enzymes in which only the amino-terminal 14 or 16 amino acids of the presequence were retained were correctly targeted and imported into the matrix. A mutant enzyme that was missing the amino-terminal 17 amino acids of the presequence produced an active enzyme, but the majority of the enzyme activity remained in the cytoplasmic compartment on cellular fractionation. Random amino acid changes were produced in the wild-type presequence by bisulfite mutagenesis of theADH3gene. The resulting ADH III protein was targeted to the mitochondria and imported into the matrix in all of the mutants tested, as judged by enzyme activity. Mutants containing amino acid changes in the carboxyl-proximal half of theADH3presequence were imported and processed to the mature form at a slower rate than the wild type, as judged by pulse-chase studies in vivo. The unprocessed precursor appeared to be unstable in vivo. It was concluded that only a small portion of the presequence contains the necessary information for correct targeting and import. Furthermore, the information for correct proteolytic processing of the presequence appears to be distinct from the targeting information and may involve secondary structure information in the presequence.
