Physiology and regulation of bacterial stress response

• Grant number: 12/10563-0
• Support Opportunities: Regular Research Grants
• Start date: September 01, 2012
• End date: August 31, 2014
• Field of knowledge: Biological Sciences - Genetics - Molecular Genetics and Genetics of Microorganisms
• Principal Investigator: Marilis Do Valle Marques
• Grantee: Marilis Do Valle Marques
• Host Institution: Instituto de Ciências Biomédicas (ICB). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

As the bacterial population grows, cells face a progressive reduction of nutrient availability that brings the need to respond slowing the reproductive rate and resetting the metabolism to withstand a long starvation period. The physiological effects of low temperature are somewhat similar to those of nutrient starvation, in that there is a reduction of ribosome function. The sensing of environmental signals is crucial for the cell to reset its gene expression to face the new situation. Small proteins containing a Cold Shock Domain (CSP) are induced at low temperature and/or stationary phase, and act as RNA chaperones, facilitating translation under these conditions, and as gene regulators. Another important system in this response is composed by the RNA helicases, which are responsible for resolving the secondary structures. The main goal of this project is to identify the regulatory mechanisms important for stress response in the alpha-proteobacterium Caulobacter crescentus. A transcriptome analysis of mutant strains for the cspC and spdR genes will be performed at stationary phase, and the respective regulons will be defined. This will allow determining the regulatory cascade that occurs upon entry into stationary phase. The molecular basis of the cspC essential role in maintaining cell viability and oxidative stress response will also be identified. The role of the RNA helicases belonging to the DEAD family in low temperature adaptation will be determined by phenotypic analysis of mutant strains and gene expression assays. (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

SANTOS, JULIANA S.; DA SILVA, CAROLINA A. P. T.; BALHESTEROS, HELOISE; LOURENCO, ROGERIO F.; MARQUES, MARILIS V.. CspC regulates the expression of the glyoxylate cycle genes at stationary phase in Caulobacter. BMC Genomics, v. 16, AUG 27 2015. (14/04046-8, 11/21883-2, 12/10563-0, 11/17513-5)

DA SILVA, CAROLINA A. P. T.; LOURENCO, ROGERIO F.; MAZZON, RICARDO R.; RIBEIRO, RODOLFO A.; MARQUES, MARILIS V.. Transcriptomic analysis of the stationary phase response regulator SpdR in Caulobacter crescentus. BMC Microbiology, v. 16, APR 12 2016. (14/04046-8, 11/18847-4, 12/10563-0, 11/17513-5)