Boose J A, Ziska S E, Henderson E J
Department of Biology, Georgetown University, Washington, DC 20057.
Dev Genet. 1988;9(4-5):569-78. doi: 10.1002/dvg.1020090433.
In order to identify the biological roles of protein-linked oligosaccharides, we have isolated mutants by a selection for amoebae with temperature-sensitive defects in glycan assembly and processing. Of these, 75% were also temperature sensitive for development [Boose and Henderson, 1986]. Two such mutants with distinct developmental phenotypes and glycosylation patterns are described. Mutant HT7 cannot complete aggregation at the restrictive temperature and is defective in expression of EDTA-resistant cohesion. The biochemical defect appears to be early in glycan processing. A revertant of HT7 has recovered aggregation capability, EDTA-resistant cohesion, and reverted almost totally to wild-type glycosylation. Mutant HT15 aggregates at the restrictive temperature but then disperses into a cell lawn. It is less deficient in EDTA-resistant cohesion than HT7 and has a different glycosylation profile. These results provide strong support for a role of protein N-linked oligosaccharides in aggregation-stage intercellular cohesion.
为了确定蛋白质连接寡糖的生物学作用，我们通过筛选在聚糖组装和加工方面具有温度敏感性缺陷的变形虫分离出了突变体。其中，75% 的突变体在发育方面也表现出温度敏感性[布斯和亨德森，1986年]。本文描述了两个具有不同发育表型和糖基化模式的此类突变体。突变体HT7在限制温度下无法完成聚集，并且在表达抗EDTA凝聚方面存在缺陷。生化缺陷似乎出现在聚糖加工的早期阶段。HT7的一个回复突变体恢复了聚集能力、抗EDTA凝聚能力，并且几乎完全恢复到野生型糖基化状态。突变体HT15在限制温度下聚集，但随后分散成细胞层。它在抗EDTA凝聚方面的缺陷比HT7少，并且具有不同的糖基化谱。这些结果为蛋白质N连接寡糖在聚集阶段细胞间凝聚中的作用提供了有力支持。
