title: Differential expression of secretion machinery during bacterial growth: SecY and SecF decrease while SecA increases during transition from exponential phase to stationary phase.
abstract: Transcription of many house-keeping genes, including secY and some other sec genes, decreases in the transition from the exponential phase to the stationary phase (feast to famine) in Bacillus subtilis. Unexpectedly and in contradiction to earlier reports, enhanced transcription was observed for another group of sec genes, including secA which codes for an essential ATPase for protein secretion. Consistent with the transcription data, the SecA protein of B. subtilis increases significantly in the stationary phase. Immunoblot analyses of Sec proteins during the transition in Escherichia coli also revealed the pronounced decreases of SecY and SecF and the increase of SecA, resulting in drastic increases of SecA/SecY and SecA/SecF ratios from exponential to stationary phases. The differential expression of Sec proteins in the stationary phase suggests the possibility of specific physiological functions.
authors.affiliation: Department of Biology, Center of Biotechnology and Drug Design, Georgia State University, 592 PSC, 161 Jesse Hill Jr. Road, Atlanta, GA, 30303, USA.
authors.forename: Chun-Kai
authors.initials: CK
authors.lastname: Yang
authors.forename: Chung-Dar
authors.initials: CD
authors.lastname: Lu
authors.forename: Phang C
authors.initials: PC
authors.lastname: Tai
mesh_terms: D001412:Bacillus subtilis / Q000254:growth & development* / Q000378:metabolism; D001426:Bacterial Proteins / Q000096:biosynthesis*; D004926:Escherichia coli / Q000254:growth & development* / Q000378:metabolism; D020869:Gene Expression Profiling; D026901:Membrane Transport Proteins / Q000096:biosynthesis*
chemical_list: D001426:Bacterial Proteins; D026901:Membrane Transport Proteins