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Rv3852 (H-NS) of Mycobacterium tuberculosis Is Not Involved in Nucleoid Compaction and Virulence Regulation.
Odermatt, Nina T; Sala, Claudia; Benjak, Andrej; Kolly, Gaëlle S; Vocat, Anthony; Lupien, Andréanne; Cole, Stewart T.
Afiliação
  • Odermatt NT; Global Health Institute, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland.
  • Sala C; Global Health Institute, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland.
  • Benjak A; Global Health Institute, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland.
  • Kolly GS; Global Health Institute, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland.
  • Vocat A; Global Health Institute, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland.
  • Lupien A; Global Health Institute, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland.
  • Cole ST; Global Health Institute, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland stewart.cole@epfl.ch.
J Bacteriol ; 199(16)2017 08 15.
Article em En | MEDLINE | ID: mdl-28559300
ABSTRACT
A handful of nucleoid-associated proteins (NAPs) regulate the vast majority of genes in a bacterial cell. H-NS, the histone-like nucleoid-structuring protein, is one of these NAPs and protects Escherichia coli from foreign gene expression. Though lacking any sequence similarity with E. coli H-NS, Rv3852 was annotated as the H-NS ortholog in Mycobacterium tuberculosis, as it resembles human histone H1. The role of Rv3852 was thoroughly investigated by immunoblotting, subcellular localization, construction of an unmarked rv3852 deletion in the M. tuberculosis genome, and subsequent analysis of the resulting Δrv3852 strain. We found that Rv3852 was predominantly present in the logarithmic growth phase with a decrease in protein abundance in stationary phase. Furthermore, it was strongly associated with the cell membrane and not detected in the cytosolic fraction, nor was it secreted. The Δrv3852 strain displayed no growth defect or morphological abnormalities. Quantitative measurement of nucleoid localization in the Δrv3852 mutant strain compared to that in the parental H37Rv strain showed no difference in nucleoid position or spread. Infection of macrophages as well as severe combined immunodeficient (SCID) mice demonstrated that loss of Rv3852 had no detected influence on the virulence of M. tuberculosis We thus conclude that M. tuberculosis Rv3852 is not involved in pathogenesis and is not a typical NAP. The existence of an as yet undiscovered Rv3852 ortholog cannot be excluded, although this role is likely played by the well-characterized Lsr2 protein.IMPORTANCEMycobacterium tuberculosis is the causative agent of the lung infection tuberculosis, claiming more than 1.5 million lives each year. To understand the mechanisms of latent infection, where M. tuberculosis can stay dormant inside the human host, we require deeper knowledge of the basic biology and of the regulatory networks. In our work, we show that Rv3852, previously annotated as H-NS, is not a typical nucleoid-associated protein (NAP) as expected from its initial annotation. Rv3852 from M. tuberculosis has neither influence on nucleoid shape or compaction nor a role in virulence. Our findings reduce the repertoire of identified nucleoid-associated proteins in M. tuberculosis to four transcription regulators and underline the importance of genetic studies to assign a function to bacterial genes.
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Texto completo: 1 Coleções: 01-internacional Base de dados: MEDLINE Assunto principal: Proteínas de Bactérias / Regulação Bacteriana da Expressão Gênica / Fatores de Virulência / Proteínas de Ligação a DNA / Mycobacterium tuberculosis Tipo de estudo: Prognostic_studies Limite: Animals / Humans Idioma: En Ano de publicação: 2017 Tipo de documento: Article

Texto completo: 1 Coleções: 01-internacional Base de dados: MEDLINE Assunto principal: Proteínas de Bactérias / Regulação Bacteriana da Expressão Gênica / Fatores de Virulência / Proteínas de Ligação a DNA / Mycobacterium tuberculosis Tipo de estudo: Prognostic_studies Limite: Animals / Humans Idioma: En Ano de publicação: 2017 Tipo de documento: Article