Determination of transcription factors and cellular signals involved in the regulation of cspC.

• Grant number: 09/12095-0
• Support Opportunities: Scholarships in Brazil - Master
• Effective date (Start): March 01, 2010
• Effective date (End): September 30, 2011
• Field of knowledge: Biological Sciences - Genetics - Molecular Genetics and Genetics of Microorganisms
• Principal Investigator: Marilis Do Valle Marques
• Grantee: Juliana Santos Nakayama
• Host Institution: Instituto de Ciências Biomédicas (ICB). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

The Cold Shock Proteins (CSPs) are low molecular weight proteins that contain a conserved Cold Shock Domain (CSD), which is conserved among prokaryotes and eukaryotes. CSPs bind to nascent RNA, preventing the formation of secondary structures in the mRNA, and overcoming the deleterious effects on translation. C. crescentus, a Gram-negative alpha-proteobacterium, possess four genes encoding CSPs (cspA, cspB, cspC and cspD). CspA and CspB are the only ones induced at low temperature and contain a single CSD. CspC and CspD have two CSD and are induced at stationary phase. Although a lot is known about the entry into stationary phase in E. coli and B. subtilis, very little is known in alpha-proteobacteria. The study of the role and expression of CspC in stationary phase in C. crescentus is important to understand the processes that lead to stationary phase adaptation and recovery from senescence. The approaches to identify the cspC regulatory factors are: screening of a library of mutants to isolate those in which the expression of cspC is low and the identification of proteins that bind to the regulatory region. There will also performed expression assays in response to different environments and to quorum sensing using a transcriptional fusion to the reporter lacZ gene, and expression will be evaluated by beta-galactosidase assays.