SIGNIFICANCE OF C-TERMINAL CYSTEINE MODIFICATIONS TO THE BIOLOGICAL-ACTIVITY OF THE SACCHAROMYCES-CEREVISIAE A-FACTOR MATING PHEROMONE
SIGNIFICANCE OF C-TERMINAL CYSTEINE MODIFICATIONS TO THE BIOLOGICAL-ACTIVITY OF THE SACCHAROMYCES-CEREVISIAE A-FACTOR MATING PHEROMONE
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DOI：
10.1128/mcb.11.7.3603
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发表时间：
1991-07-01
影响因子：
5.3
通讯作者：
BECKER, JM
中科院分区：
文献类型：
--
作者：
MARCUS, S;CALDWELL, GA;BECKER, JM
我们进行了酿酒酵母a因子（NH2-YIIKGVFWDPAC[s-法尼基]-COOCH3）和几种Cys-12类似物的全合成，以确定s-法尼基化和羧基端甲基酯化对这种脂肽交配信息素的生物活性的意义。用氢原子取代法尼基或羧基端甲酯会导致生物活性的显著降低，但不是完全丧失，这是通过各种实验测量的。此外，法尼基和甲酯基团都可以被其他取代基取代以产生具有生物活性的类似物。当半胱氨酸硫上的戊烯基单位从3个减少到1个时，a因子的生物活性降低，并且a因子类似物的s -法尼基被s -十六烷基取代比s -甲基a因子类似物更有活性。因此，通过两种类型的修饰，a因子活性随着s -烷基变得更大和更疏水而增加。在外源a因子存在的情况下，a因子结构基因缺失的MATa细胞（mfa1 mfa2突变体）能够与sst2或野生型mat - α细胞交配，这表明MATa细胞主动产生a因子并不是交配的绝对必要条件。发现各种a因子类似物也能部分恢复这些菌株的交配，并且它们在交配恢复试验中的相对活性与本研究中使用的其他试验中的活性相似。在野生型mat - α菌株和MATaste6突变体的杂交中，添加外源a因子不能恢复交配，这表明STE6基因产物除了分泌a因子外，还在交配中起作用。
We have undertaken total synthesis of the Saccharomyces cerevisiae a-factor (NH2-YIIKGVFWDPAC[S-farnesyl]-COOCH3) and several Cys-12 analogs to determine the significance of S-farnesylation and carboxy-terminal methyl esterification to the biological activity of this lipopeptide mating pheromone. Replacement of either the farnesyl group or the carboxy-terminal methyl ester by a hydrogen atom resulted in marked reduction but not total loss of bioactivity as measured by a variety of assays. Moreover, both the farnesyl and methyl ester groups could be replaced by other substituents to produce biologically active analogs. The bioactivity of a-factor decreased as the number of prenyl units on the cysteine sulfur decreased from three to one, and an a-factor analog having the S-farnesyl group replaced by an S-hexadecanyl group was more active than an S-methyl a-factor analog. Thus, with two types of modifications, a-factor activity increased as the S-alkyl group became bulkier and more hydrophobic. MATa cells having deletions of the a-factor structural genes (mfa1 mfa2 mutants) were capable of mating with either sst2 or wild-type MAT-alpha cells in the presence of exogenous a-factor, indicating that it is not absolutely essential for MATa cells to actively produce a-factor in order to mate. Various a-factor analogs were found to partially restore mating to these strains as well, and their relative activities in the mating restoration assay were similar to their activities in the other assays used in this study. Mating was not restored by addition of exogenous a-factor to a cross of a wild-type MAT-alpha strain and a MATaste6 mutant, indicating a role of the STE6 gene product in mating in addition to its secretion of a-factor.