Compensatory Evolution of Gene Regulation in Response to Stress by Escherichia coli Lacking RpoS Export

@article{citeulike:6065299, abstract = {The RpoS sigma factor protein of Escherichia coli RNA polymerase is the master transcriptional regulator of physiological responses to a variety of stresses. This stress response comes at the expense of scavenging for scarce resources, causing a trade-off between stress tolerance and nutrient acquisition. This trade-off favors non-functional rpoS alleles in nutrient-poor environments. We used experimental evolution to explore how natural selection modifies the regulatory network of strains lacking RpoS when they evolve in an osmotically stressful environment. We found that strains lacking RpoS adapt less variably, in terms of both fitness increase and changes in patterns of transcription, than strains with functional RpoS. This phenotypic uniformity was caused by the same adaptive mutation in every independent population: the insertion of IS 10 into the promoter of the otsBA operon. OtsA and OtsB are required to synthesize the osmoprotectant trehalose, and transcription of otsBA requires RpoS in the wild-type genetic background. The evolved IS 10 insertion rewires expression of otsBA from RpoS-dependent to RpoS-independent, allowing for partial restoration of wild-type response to osmotic stress. Our results show that the regulatory networks of bacteria can evolve new structures in ways that are both rapid and repeatable.}, author = {Stoebel, Daniel M. and Hokamp, Karsten and Last, Michael S. and Dorman, Charles J.}, citeulike-article-id = {6065299}, citeulike-linkout-0 = {http://dx.doi.org/10.1371/journal.pgen.1000671}, day = {2}, doi = {10.1371/journal.pgen.1000671}, journal = {PLoS Genet}, keywords = {bacteria, e\_coli, evolution, sigma\_factor, stress\_response}, month = {October}, number = {10}, pages = {e1000671+}, posted-at = {2009-11-03 23:33:51}, priority = {2}, publisher = {Public Library of Science}, title = {Compensatory Evolution of Gene Regulation in Response to Stress by Escherichia coli Lacking RpoS}, url = {http://dx.doi.org/10.1371/journal.pgen.1000671}, volume = {5}, year = {2009} }

TY - JOUR ID - citeulike:6065299 L3 - citeulike-article-id:6065299 N2 - The RpoS sigma factor protein of Escherichia coli RNA polymerase is the master transcriptional regulator of physiological responses to a variety of stresses. This stress response comes at the expense of scavenging for scarce resources, causing a trade-off between stress tolerance and nutrient acquisition. This trade-off favors non-functional rpoS alleles in nutrient-poor environments. We used experimental evolution to explore how natural selection modifies the regulatory network of strains lacking RpoS when they evolve in an osmotically stressful environment. We found that strains lacking RpoS adapt less variably, in terms of both fitness increase and changes in patterns of transcription, than strains with functional RpoS. This phenotypic uniformity was caused by the same adaptive mutation in every independent population: the insertion of IS 10 into the promoter of the otsBA operon. OtsA and OtsB are required to synthesize the osmoprotectant trehalose, and transcription of otsBA requires RpoS in the wild-type genetic background. The evolved IS 10 insertion rewires expression of otsBA from RpoS-dependent to RpoS-independent, allowing for partial restoration of wild-type response to osmotic stress. Our results show that the regulatory networks of bacteria can evolve new structures in ways that are both rapid and repeatable. IS - 10 JF - PLoS Genet TI - Compensatory Evolution of Gene Regulation in Response to Stress by Escherichia coli Lacking RpoS PB - Public Library of Science VL - 5 SP - e1000671 KW - bacteria KW - e_coli KW - evolution KW - sigma_factor KW - stress_response AU - Stoebel, Daniel AU - Hokamp, Karsten AU - Last, Michael AU - Dorman, Charles PY - 2009/10/02/ UR - http://dx.doi.org/10.1371/journal.pgen.1000671 ER -