title: ICAT-based comparative proteomic analysis of non-replicating persistent Mycobacterium tuberculosis.
abstract: The non-replicating persistence (NRP) phenotype of Mycobacterium tuberculosis (NRP-TB) is assumed to be responsible for the maintenance of latent infection and the requirement of a long treatment duration for active tuberculosis. Isotope coded affinity tag-based proteomic analysis was used for the determination of the relative expression of large numbers of M. tuberculosis proteins during oxygen self-depletion under controlled conditions in a multi-chambered fermentor. Expression of the alpha-crystallin homolog protein, acr, was monitored and quantified to confirm entry into NRP. Relative expression of 586 and 628 proteins was determined in log phase vs. early stage NRP (NRP-1) and log phase vs. later stage NRP (NRP-2), respectively. Relative to expression in log phase and using an abundance ratio of +/-2.0 as a cutoff, 6.5% and 20.4% of proteins were found to be upregulated in NRP-1 and NRP-2, respectively while 20.3% and 13.4% were downregulated, respectively. Functional profiling revealed that 42.1%/39.8% of upregulated proteins and 41.2%/45.2% of downregulated proteins in NRP-1/NRP-2, respectively, were involved in small molecule metabolism. Among those proteins the highest proportions of 37.5% in NRP-1 were involved with degradation and of 45.1% in NRP-2 with energy metabolism. These results suggest distinct protein expression profiles in NRP-1 and NRP-2.
authors.affiliation: Institute for Tuberculosis Research, College of Pharmacy, University of Illinois at Chicago, 833 S. Wood St, Chicago, IL 60612, USA. jkcn01@uic.edu <jkcn01@uic.edu>
authors.forename: Sang Hyun
authors.initials: SH
authors.lastname: Cho
authors.forename: David
authors.initials: D
authors.lastname: Goodlett
authors.forename: Scott
authors.initials: S
authors.lastname: Franzblau
mesh_terms: D001426:Bacterial Proteins / Q000096:biosynthesis* / Q000235:genetics; D003114:Colony-Forming Units Assay; D015536:Down-Regulation; D004591:Electrophoresis, Polyacrylamide Gel; D005285:Fermentation; D020869:Gene Expression Profiling / Q000379:methods; D015964:Gene Expression Regulation, Bacterial; D009169:Mycobacterium tuberculosis / Q000187:drug effects / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D010100:Oxygen / Q000494:pharmacology; D020543:Proteome; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods; D015854:Up-Regulation; D038201:alpha-Crystallins / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D020543:Proteome; D038201:alpha-Crystallins; D010100:Oxygen