Adaptive divergence in experimental populations of Pseudomonas fluorescens.: II.: Role of the GGDEF regulator WspR in evolution and development of the wrinkly spreader phenotype
Adaptive divergence in experimental populations of Pseudomonas fluorescens.: II.: Role of the GGDEF regulator WspR in evolution and development of the wrinkly spreader phenotype
复制标题
DOI：
10.1534/genetics.106.055863
复制
发表时间：
2006-06-01
期刊：
影响因子：
3.3
通讯作者：
Rainey, Paul B.
中科院分区：
文献类型：
--
作者：
Goymer, Patrick;Kahn, Sophie G.;Rainey, Paul B.
皱纹传播者（WS）基因型在接受适应性辐射的模型假单胞菌种群中反复进化。先前的工作确定了有助于 WS 进化成功的基因。在这里，我们仔细研究了 GGDEF 反应调节蛋白 WspR，并表明它对于 WS 来说既是必要的也是充分的。 WspR 的激活通过磷酸化发生，不同水平的激活会在 WS 基因型之间产生表型差异。通过诱变产生了 wspR 的五个等位基因，每个等位基因编码具有单个氨基酸取代的蛋白质。两个等位基因具有组成型活性，导致祖先基因型形成 WS 表型；表型效应是等位基因特异性的并且与磷酸化无关。三个等位基因包含 GGDEF 结构域的变化，当在 WS 中过度表达时，会导致恢复到祖先表型。通过过度表达释放的 N 末端结构域来模拟这种效应的能力表明，在 WS 中，WspR 上游的调控组件过度活跃。为了将核苷酸水平的变化与适应性联系起来，在结构化和非结构化环境中检查了变异等位基因的影响：等位基因具有适应性和有害作用，并且在不同环境中的权衡显而易见。尽管wspR内的突变倾向于产生WS，但对独立获得的WS的wspR前53位的序列分析显示该基因中没有序列变化的证据。
Wrinkly spreader (WS) genotypes evolve repeatedly in model Pseudomonas populations undergoing adaptive radiation. Previous work identified genes contributing to the evolutionary success of WS. Here we scrutinize the GGDEF response regulator protein WspR and show that it is both necessary and sufficient for WS. Activation of WspR occurs by phosphorylation and different levels of activation generate phenotypic differences among WS genotypes. Five alleles of wspR each encoding a protein with a single amino acid substitution, were generated by mutagenesis. Two alleles are constitutively active and cause the ancestral genotype to develop a WS phenotype; the phenotypic effects are allele specific and independent of phosphorylation. Three alleles contain changes in the GGDEF domain and when overexpressed in WS cause reversion to the ancestral phenotype. Ability to mimic this effect by overexpression of a liberated N-terminal domain shows that in WS, regulatory components upstream of WspR are overactive. To connect changes at the nucleotide level with fitness, the effects of variant alleles were examined in both structured and unstructured environments: alleles had adaptive and deleterious effects With trade-offs evident across environments. Despite the proclivity of mutations within wspR to generate WS, sequence analysis of wspR front 53 independently obtained WS showed no evidence of sequence change in this gene.