Signal processing, glycosylation, and secretion of mutant hemagglutinins of a human influenza virus by Saccharomyces cerevisiae.
Signal processing, glycosylation, and secretion of mutant hemagglutinins of a human influenza virus by Saccharomyces cerevisiae.
复制标题
酿酒酵母对人流感病毒突变血凝素的信号处理、糖基化和分泌。
DOI：
10.1128/mcb.7.4.1476-1485.1987
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发表时间：
1987
影响因子：
5.3
通讯作者：
Nayak,DP
中科院分区：
文献类型：
--
作者：
AbdulJabbar,M;Nayak,DP
我们研究了酵母菌对人流感病毒突变血凝素（HA）的信号识别、转运和分泌的性质。编码流感HA变体形式的cDNA序列在酿酒酵母中表达。用其N-末端信号肽合成的HA多肽（HA 500和HA 325）被正确地靶向膜区室，在膜区室中它们被糖基化。相反，缺乏信号肽的HA多肽（HA 484和HA 308）在细胞质中表达并且不经历任何糖苷修饰，证明了异源信号序列在酿酒酵母中易位的早期步骤中的重要性。HA 500和HA 325多肽的N-末端氨基酸序列的分析证明了信号肽的正确切割，表明异源信号肽的结构相容性，以有效地识别和酵母易位机制的加工。膜螯合和糖基化的HA多肽在具有信号负性的非糖基化HA分子的S.尽管无锚定HA（HA 500）和HA 1（HA 325）多肽都有效地靶向膜，但它们的糖基化和转运模式被证明是不同的。在脉冲追踪过程中，HA 500保持与细胞相关，没有可检测的分泌到细胞外培养基中，而HA 325分泌到培养基中。此外，只有细胞相关的和分泌形式的HA 325，而不是HA 500似乎已经经历了高糖基化与大量添加的高分子量外链甘露聚糖。这两个突变体的HA观察到的表型行为的可能原因进行了讨论。
We investigated the nature of signal recognition, transport, and secretion of mutant hemagglutinins (HAs) of a human influenza virus by the yeastSaccharomyces cerevisiae. The cDNA sequences encoding variant forms of influenza HA were expressed inS. cerevisiae. The HA polypeptides (HA500 and HA325) that were synthesized with their N-terminal signal peptides were correctly targeted to the membrane compartment where they were glycosylated. In contrast, the HA polypeptides (HA484 and HA308) lacking the signal peptide were expressed in the cytoplasm and did not undergo any glycosidic modification, demonstrating the importance of the heterologous signal sequence in the early steps of translocation inS. cerevisiae. The analysis of the N-terminal amino acid sequence of HA500 and HA325 polypeptides demonstrated the correct cleavage of the signal peptide, indicating the structural compatibility of a heterologous signal peptide for efficient recognition and processing by the yeast translocation machinery. The membrane-sequestered and glycosylated HA polypeptides were relatively stable inS. cerevisiaecompared with the signal-minus, nonglycosylated HA molecules. Although both the anchor-minus HA (HA500) and HA1 (HA325) polypeptides were targeted efficiently to the membrane, their glycosylation and transport patterns were shown to be different. During pulse-chase, the HA500 remained cell-associated with no detectable secretion into the extracellular medium, whereas the HA325 secreted into the medium. Furthermore, only the cell-associated and secreted forms of HA325 and not HA500 appeared to have undergone hyperglycosylation with the extensive addition of high-molecular-weight outer-chain mannans. Possible reasons for the observed phenotypic behavior of these two mutant HAs are discussed.