ICAT-based comparative proteomic analysis of non-replicating persistent Mycobacterium tuberculosis

Tuberculosis (Edinb). 2006 Nov;86(6):445-60. doi: 10.1016/j.tube.2005.10.002. Epub 2005 Dec 20.

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.

MeSH terms

  • Bacterial Proteins / biosynthesis*
  • Bacterial Proteins / genetics
  • Colony-Forming Units Assay
  • Down-Regulation
  • Electrophoresis, Polyacrylamide Gel
  • Fermentation
  • Gene Expression Profiling / methods
  • Gene Expression Regulation, Bacterial
  • Mycobacterium tuberculosis / drug effects
  • Mycobacterium tuberculosis / genetics
  • Mycobacterium tuberculosis / growth & development
  • Mycobacterium tuberculosis / metabolism*
  • Oxygen / pharmacology
  • Proteome
  • Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / methods
  • Up-Regulation
  • alpha-Crystallins / metabolism

Substances

  • Bacterial Proteins
  • Proteome
  • alpha-Crystallins
  • Oxygen