A mutation that affects fibril protein, development, cohesion and gene expression in Myxococcus xanthus.
A mutation that affects fibril protein, development, cohesion and gene expression in Myxococcus xanthus.
复制标题
影响黄色粘球菌中原纤维蛋白、发育、凝聚力和基因表达的突变。
DOI：
10.1099/00221287-143-12-3683
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发表时间：
1997
期刊：
影响因子：
--
通讯作者：
Dworkin,Martin
中科院分区：
文献类型：
--
作者：
Smith,DanielR;Dworkin,Martin
细胞外基质原纤维参与社会原核生物黄色粘球菌的细胞间相互作用。原纤维由碳水化合物主链和一组 5 个完整原纤维蛋白 (IFP) 组成，范围从 14 到 66 kDa。作为了解 IFP 功能的尝试的一部分，如全细胞和分离的原纤维的蛋白质印迹分析所示，产生了缺乏原纤维蛋白之一 IFP-1:20 的突变体 (ifp-1:20)。与亲本菌株不同，突变体的原纤维很容易通过剪切力从细胞中去除。 inifp-1:20的发育异常——聚集和早期土丘形成延迟了6-10小时，并且从未形成成熟的子实体。粘孢子产量也大大减少。此外，原纤维介导的内聚力 inifp-1:20 也发生了变化。凝聚力产生细胞链，而不是亲本菌株所见的特征性细胞团。与野生型原纤维不同，分离的ifp-1:20原纤维不能挽救非粘性、原纤维阴性dsp细胞的内聚力，这支持了原纤维在功能上发生改变的观点。该突变还使 Ω4521（一种在发育早期表达的转座子插入突变体）的发育基因表达降低了三到四倍。后期发育基因融合的表达没有受到影响，这表明原纤维可能不是后期发育基因表达所必需的。这些数据表明，完整的原纤维可能在发育早期发挥作用，以促进细胞紧密接近以进行信号交换。
Extracellular matrix fibrils are involved in the cell-cell interactions of the social prokaryote,Myxococcus xanthus.The fibrils are composed of a carbohydrate backbone and a set of five integral fibrillar proteins (IFPs) ranging from 14 to 66 kDa. As part of an attempt to understand the function(s) of the IFPs, a mutant (ifp-1:20) was generated that lacks IFP-1:20, one of the fibril proteins, as shown by Western blot analysis of both whole cells and isolated fibrils. Unlike those of the parent strain, the fibrils of the mutant were removed easily from the cells by shear forces. Development inifp-1:20was aberrant - aggregation and early mound formation were delayed by 6-10 h and mature fruiting bodies never formed. Myxospore production was also greatly reduced. Additionally, fibril-mediated cohesion inifp-1:20was changed. Cohesion resulted in chains of cells rather than the characteristic clumps of cells seen for the parent strain. Isolatedifp-1:20fibrils, unlike wild-type fibrils, could not rescue cohesion of non-cohesive, fibril-negativedspcells, supporting the notion that the fibrils were functionally altered. The mutation also reduced developmental gene expression by three- to fourfold in Ω4521, a transposon insertion mutant expressed early in development. Expression of a later developmental gene fusion was not affected, suggesting that the fibrils may not be required for later developmental gene expression. These data suggest that intact fibrils may function early in development to facilitate close cell proximity for signal exchange.