title: Mycobacterium tuberculosis CwsA overproduction modulates cell division and cell wall synthesis.
abstract: We recently showed that two small membrane proteins of Mycobacterium tuberculosis, CwsA and CrgA, interact with each other, and that loss of CwsA in M. smegmatis is associated with defects in the cell division and cell wall synthesis processes. Here we show that CwsA overproduction also affected growth, cell division and cell shape of M. smegmatis and M. tuberculosis. CwsA overproduction in M. tuberculosis led to increased sensitivity to cefsulodin, a penicillin-binding protein (PBP) 1A/1B targeting beta (β) -lactam, but was unaffected by other β-lactams and vancomycin. A M. smegmatis cwsA overexpressing strain showed bulgy cells, increased fluorescent vancomycin staining and altered localization of Wag31-mCherry fusion protein. However, the levels of phosphorylated Wag31, important for optimal peptidoglycan synthesis and growth in mycobacteria, were not affected. Interestingly, CwsA overproduction in E. coli led to the formation of large rounded cells that eventually lysed whereas the overproduction of FtsZ along with CwsA reversed this phenotype. Together, our results emphasize that optimal levels of CwsA are required for regulated cell wall synthesis, hence maintenance of cell shape, and that CwsA likely interacts with and modulates the activities of other cell wall synthetic components including PBPs.
authors.affiliation: Biomedical Research, The University of Texas Health Science Center @ Tyler, Tyler, TX 75708, USA.
authors.forename: P
authors.initials: P
authors.lastname: Plocinski
authors.affiliation: Biomedical Research, The University of Texas Health Science Center @ Tyler, Tyler, TX 75708, USA.
authors.forename: L
authors.initials: L
authors.lastname: Martinez
authors.affiliation: Biomedical Research, The University of Texas Health Science Center @ Tyler, Tyler, TX 75708, USA.
authors.forename: K
authors.initials: K
authors.lastname: Sarva
authors.affiliation: Biomedical Research, The University of Texas Health Science Center @ Tyler, Tyler, TX 75708, USA.
authors.forename: R
authors.initials: R
authors.lastname: Plocinska
authors.affiliation: Biomedical Research, The University of Texas Health Science Center @ Tyler, Tyler, TX 75708, USA.
authors.forename: M
authors.initials: M
authors.lastname: Madiraju
authors.affiliation: Biomedical Research, The University of Texas Health Science Center @ Tyler, Tyler, TX 75708, USA. Electronic address: malini.rajagopalan@uthct.edu.
authors.forename: M
authors.initials: M
authors.lastname: Rajagopalan
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001426:Bacterial Proteins / Q000378:metabolism*; D002455:Cell Division; D002473:Cell Wall / Q000378:metabolism*; D002478:Cells, Cultured; D004926:Escherichia coli / Q000187:drug effects / Q000254:growth & development*; D015964:Gene Expression Regulation, Bacterial; D006801:Humans; D015151:Immunoblotting; D007553:Isotope Labeling; D008565:Membrane Proteins / Q000378:metabolism*; D020102:Mycobacterium smegmatis / Q000378:metabolism*; D009169:Mycobacterium tuberculosis / Q000378:metabolism*; D011485:Protein Binding; D025941:Protein Interaction Mapping; D015854:Up-Regulation
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D008565:Membrane Proteins
keywords: Cell wall synthesis Cell division; CwsA; FtsZ; Mycobacterium