Mohandas Poornima, Budell William C, Mueller Emily, Au Andrew, Bythrow Glennon V, Quadri Luis E N
Biology Department, Brooklyn College, City University of New York, Brooklyn, NY 11210, USA Biology Program, Graduate Center, City University of New York, NY 10016, USA.
Biology Department, Brooklyn College, City University of New York, Brooklyn, NY 11210, USA.
FEMS Microbiol Lett. 2016 Mar;363(5):fnw016. doi: 10.1093/femsle/fnw016. Epub 2016 Jan 26.
Phthiocerol dimycocerosates (PDIMs) and phenolic glycolipids (PGLs) contribute to the pathogenicity of several mycobacteria. Biosynthesis of these virulence factors requires polyketide synthases and other enzymes that represent potential targets for the development of adjuvant antivirulence drugs. We used six isogenic Mycobacterium marinum mutants, each with a different gene knockout in the PDIM/PGL biosynthetic pathway, to probe the pleiotropy of mutations leading to PDIM(-) PGL(-), PDIM(+) PGL(-) or PDIM(-) PGL(+) phenotypes. We evaluated the M. marinum mutants for changes in antibiotic susceptibility, cell envelope permeability, biofilm formation, surface properties, sliding motility and virulence in an amoeba model. The analysis also permitted us to begin exploring the hypothesis that different gene knockouts rendering the same PDIM and/or PGL deficiency phenotypes lead to M. marinum mutants with equivalent pleiotropic profiles. Overall, the results of our study revealed a complex picture of pleiotropic patterns emerging from different gene knockouts, uncovered unexpected phenotypic inequalities between mutants, and provided new insight into the phenotypic consequences of gene knockouts in the PDIM/PGL biosynthetic pathway.
分枝菌酸二霉菌酸酯(PDIMs)和酚糖脂(PGLs)对几种分枝杆菌的致病性有影响。这些毒力因子的生物合成需要聚酮合酶和其他酶,这些酶是开发辅助抗毒力药物的潜在靶点。我们使用了六个海洋分枝杆菌同基因突变体,每个突变体在PDIM/PGL生物合成途径中都有不同的基因敲除,以探究导致PDIM(-)PGL(-)、PDIM(+)PGL(-)或PDIM(-)PGL(+)表型的突变的多效性。我们评估了海洋分枝杆菌突变体在抗生素敏感性、细胞壁通透性、生物膜形成、表面特性、滑动运动性以及在变形虫模型中的毒力方面的变化。该分析还使我们能够开始探索这样一个假设,即导致相同PDIM和/或PGL缺陷表型的不同基因敲除会导致具有等效多效性特征的海洋分枝杆菌突变体。总体而言,我们的研究结果揭示了不同基因敲除产生的多效性模式的复杂情况,发现了突变体之间意想不到的表型不平等,并为PDIM/PGL生物合成途径中基因敲除的表型后果提供了新的见解。