The cellulose synthase gene of Dictyostelium
The cellulose synthase gene of Dictyostelium
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DOI：
10.1073/pnas.040565697
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发表时间：
2000-02-29
影响因子：
11.1
通讯作者：
Loomis, WF
中科院分区：
文献类型：
--
作者：
Blanton, RL;Fuller, D;Loomis, WF
纤维素是在社会性变形虫盘基网柄阿米巴（Dictyosteelicdiscoideum）发育过程中形成的细胞外基质的主要成分。我们分离插入突变体，未能积累纤维素，并没有纤维素合成酶的活动在任何阶段的发展。发育在无效突变体中正常进行，直到茎形成的开始，在这一点上，顶点结构倒塌到自己身上，然后再次尝试顶点。在突变体中没有产生孢子或柄细胞，所有细胞最终都溶解了。预测的破坏基因产物（dcsA）与细菌中纤维素酶催化亚基具有显著的相似性。在用表达完整dcsA基因的构建体转化的菌株中，酶活性和正常发育得到恢复。携带该构建体的生长阿米巴积累了dcsA的蛋白质产物，但直到它们发育至少1小时才产生纤维素。这些研究直接表明，dcsA的产物对于纤维素的合成是必需的，但不是充分的。
Cellulose is a major component of the extracellular matrices formed during development of the social amoeba, Dictyostelium discoideum. We isolated insertional mutants that failed to accumulate cellulose and had no cellulose synthase activity at any stage of development. Development proceeded normally in the null mutants up to the beginning of stalk formation, at which point the culminating structures collapsed onto themselves, then proceeded to attempt culmination again. No spores or stalk cells were ever made in the mutants, with all cells eventually lysing. The predicted product of the disrupted gene (dcsA) showed significant similarity to the catalytic subunit of cellulose synthases found in bacteria, Enzyme activity and normal development were recovered in strains transformed with a construct expressing the intact dcsA gene. Growing amoebae carrying the construct accumulated the protein product of dcsA, but did not make cellulose until they had developed for at least in hr, These studies show directly that the product of dcsA is necessary, but not sufficient, for synthesis of cellulose.