Shotgun proteomic analysis of drug treated mycobacteria

Mycobacterium smegmatis is particularly useful in studying basic cellular processes of relevance to pathogenic mycobacteria. We use anti‐tuberculosis drugs INH, EMB and 5Cl‐PZA to treat M. smegmatis , exploring alterations of protein expression profiles in response to drug treatments. Multidimensional chromatography coupled with tandem mass spectrometry, in combination with the partially completed genome sequence were used to detect and identify ~2000 distinct proteins from M. smegmatis with ~ 5% false positive identification rate, and absolute protein expression levels were estimated from the shotgun proteomics data. Translation, cell cycle control, and energy production are down‐regulated in three drug treatments. By contrast, systems related to the drug's targets, such as lipid, amino acid, nucleotide metabolism and transport are up‐regulated, with specific protein expression changes associtated with each drug treatment. We provide a large‐scale analysis of the M. smegmatis proteomic response to INH, EMB and 5‐Cl‐PZA and elucidate the drugs’ systematic effects on mycobacterial cells.