title: CspC and CspD are essential for Caulobacter crescentus stationary phase survival.
abstract: The cold shock response in bacteria involves the expression of low-molecular weight cold shock proteins (CSPs) containing a nucleic acid-binding cold shock domain (CSD), which are known to destabilize secondary structures on mRNAs, facilitating translation at low temperatures. Caulobacter crescentus cspA and cspB are induced upon cold shock, while cspC and cspD are induced during stationary phase. In this work, we determined a new coding sequence for the cspC gene, revealing that it encodes a protein containing two CSDs. The phenotypes of C. crescentus csp mutants were analyzed, and we found that cspC is important for cells to maintain viability during extended periods in stationary phase. Also, cspC and cspCD strains presented altered morphology, with frequent non-viable filamentous cells, and cspCD also showed a pronounced cell death at late stationary phase. In contrast, the cspAB mutant presented increased viability in this phase, which is accompanied by an altered expression of both cspC and cspD, but the triple cspABD mutant loses this characteristic. Taken together, our results suggest that there is a hierarchy of importance among the csp genes regarding stationary phase viability, which is probably achieved by a fine tune balance of the levels of these proteins.
authors.affiliation: Departamento de Microbiologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo, SP 05508-000, Brazil.
authors.forename: Heloise
authors.initials: H
authors.lastname: Balhesteros
authors.forename: Ricardo R
authors.initials: RR
authors.lastname: Mazzon
authors.forename: Carolina A P T
authors.initials: CA
authors.lastname: da Silva
authors.forename: Elza A S
authors.initials: EA
authors.lastname: Lang
authors.forename: Marilis V
authors.initials: MV
authors.lastname: Marques
mesh_terms: D000222:Adaptation, Physiological; D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D016935:Caulobacter crescentus / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism; D003080:Cold Temperature; D004247:DNA / Q000235:genetics; D017353:Gene Deletion; D005798:Genes, Bacterial; D005816:Genetic Complementation Test; D006360:Heat-Shock Proteins / Q000235:genetics / Q000378:metabolism*; D050296:Microbial Viability; D008969:Molecular Sequence Data; D017422:Sequence Analysis, DNA
chemical_list: D001426:Bacterial Proteins; C088099:CspC protein, bacteria; C088098:CspD protein, bacteria; D006360:Heat-Shock Proteins; D004247:DNA