title: Analysis of expression and regulatory functions of the ribosome-binding protein TypA in Mycobacterium tuberculosis under stress conditions.
abstract: In many bacterial species, the translational GTPase TypA acts as a global stress- and virulence regulator and also mediates resistance to the antimicrobial peptide BPI. On the chromosome of M. tuberculosis, typA is located next to narGHJI, which plays a role in adaptation of the pathogen to various environmental conditions. Here, we show that Mycobacterium tuberculosis is sensitive to P2, a derivative of BPI. Using a typA mutant of M. tuberculosis, we found this phenotype to be independent of TypA. We further tested typA expression in M. tuberculosis under defined stress conditions, such as oxygen- and nutrient depletion, low pH, heat shock, antibiotic stress and the presence of P2, and found that typA expression remains unaffected by any of these conditions. Analysis of growth and whole-genome expression revealed similar growth kinetics and gene expression profiles of the wild type and the mutant under normal growth conditions as well as under stress conditions. Our results suggest that in contrast to the findings in other bacteria, TypA does not act as a global stress- and virulence regulator in M. tuberculosis.
authors.affiliation: Department of Medical Microbiology and Hospital Epidemiology, Hannover Medical School, Carl-Neuberg-Strasse 1, 30625 Hannover, Germany.
authors.forename: Julia C
authors.initials: JC
authors.lastname: Micklinghoff
authors.forename: Mascha
authors.initials: M
authors.lastname: Schmidt
authors.forename: Robert
authors.initials: R
authors.lastname: Geffers
authors.forename: Werner
authors.initials: W
authors.lastname: Tegge
authors.forename: Franz-Christoph
authors.initials: FC
authors.lastname: Bange
mesh_terms: D000222:Adaptation, Physiological; D023181:Antimicrobial Cationic Peptides / Q000494:pharmacology / Q000502:physiology; D001426:Bacterial Proteins / Q000235:genetics / Q000502:physiology*; D001798:Blood Proteins / Q000494:pharmacology / Q000502:physiology; D020558:GTP Phosphohydrolases / Q000235:genetics / Q000502:physiology*; D017353:Gene Deletion; D020869:Gene Expression Profiling; D015964:Gene Expression Regulation, Bacterial; D018869:Heat-Shock Response; D050296:Microbial Viability; D009169:Mycobacterium tuberculosis / Q000235:genetics / Q000254:growth & development / Q000472:pathogenicity / Q000502:physiology*; D010446:Peptide Fragments / Q000494:pharmacology / Q000502:physiology; D012270:Ribosomes / Q000378:metabolism; D013312:Stress, Physiological; D014158:Transcription, Genetic; D014774:Virulence
chemical_list: D023181:Antimicrobial Cationic Peptides; D001426:Bacterial Proteins; D001798:Blood Proteins; D010446:Peptide Fragments; C021623:bactericidal permeability increasing protein; D020558:GTP Phosphohydrolases