title: Pathway-selective sensitization of Mycobacterium tuberculosis for target-based whole-cell screening.
abstract: Whole-cell screening of Mycobacterium tuberculosis (Mtb) remains a mainstay of drug discovery, but subsequent target elucidation often proves difficult. Conditional mutants that underexpress essential genes have been used to identify compounds with known mechanism of action by target-based whole-cell screening (TB-WCS). Here, the feasibility of TB-WCS in Mtb was assessed by generating mutants that conditionally express pantothenate synthetase (panC), diaminopimelate decarboxylase (lysA), and isocitrate lyase (icl1). The essentiality of panC and lysA, and conditional essentiality of icl1 for growth on fatty acids, was confirmed. Depletion of PanC and Icl1 rendered mutants hypersensitive to target-specific inhibitors. Stable reporter strains were generated for use in high-throughput screening, and their utility was demonstrated by identifying compounds that display greater potency against a PanC-depleted strain. These findings illustrate the power of TB-WCS as a tool for tuberculosis drug discovery.
authors: Molecular Mycobacteriology Research Unit and DST/NRF Centre of Excellence for Biomedical TB Research, University of the Witwatersrand and the National Health Laboratory Service, Johannesburg 2000, South Africa. garth.abrahams@uct.ac.za
authors: Garth L
authors: GL
authors: Abrahams
authors: Anuradha
authors: A
authors: Kumar
authors: Suzana
authors: S
authors: Savvi
authors: Alvin W
authors: AW
authors: Hung
authors: Shijun
authors: S
authors: Wen
authors: Chris
authors: C
authors: Abell
authors: Clifton E
authors: CE
authors: Barry
authors: David R
authors: DR
authors: Sherman
authors: Helena I M
authors: HI
authors: Boshoff
authors: Valerie
authors: V
authors: Mizrahi
mesh_terms: D001426:Bacterial Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D002262:Carboxy-Lyases / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D055808:Drug Discovery; D057166:High-Throughput Screening Assays; D007522:Isocitrate Lyase / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D009169:Mycobacterium tuberculosis / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D010453:Peptide Synthases / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D054852:Small Molecule Libraries / Q000494:pharmacology; D013329:Structure-Activity Relationship
chemical_list: D001426:Bacterial Proteins; D054852:Small Molecule Libraries; D002262:Carboxy-Lyases; C489813:LysA protein, Mycobacterium tuberculosis; D007522:Isocitrate Lyase; D010453:Peptide Synthases; C022318:pantothenate synthetase