Cassette mutagenic analysis of the yeast invertase signal peptide: effects on protein translocation.
Cassette mutagenic analysis of the yeast invertase signal peptide: effects on protein translocation.
复制标题
酵母转化酶信号肽的盒式诱变分析：对蛋白质易位的影响。
DOI：
10.1128/mcb.9.8.3400-3410.1989
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发表时间：
1989
影响因子：
5.3
通讯作者：
Smith,M
中科院分区：
文献类型：
--
作者：
Ngsee,JK;Hansen,W;Walter,P;Smith,M
The coding sequence of theSUC2locus was placed under the control of the constitutiveADH1promoter and transcription terminator in a centromere-based yeast plasmid vector from which invertase is expressed in a Sue−strain ofSaccharomyces cerevisiae.Mutants in the signal peptide sequence were produced by replacing this region of the gene with synthetic oligonucleotide cassettes containing mixtures of nucleotides at several positions. The mutants could be divided into three classes on the basis of the ability to secrete invertase. Class I mutants produced secreted invertase but in reduced amount. The class II mutant, 4-55B, also exhibited reduced a level of invertase, but a significant fraction of the enzyme was intracellular. Class III mutants were partially defective in translocation from the cytoplasm to the endoplasmic reticulum and produced enzymat-ically active, unglycosylated preinvertase in the cytoplasm. Class III mutant preinvertases were also defective in translocation across canine pancreas microsomes. These results suggested that the reduced level of invertase resulted from proteolytic degradation of inefficiently transported intermediates. Comparison of the sequences of the mutant signal peptides indicated that amino acids at the extreme amino terminus and adjacent to the cleavage site play a crucial role in the secretory process when combined with a mutation within the hydrophobic core.
