title: Profiling the Proteome of Mycobacterium tuberculosis during Dormancy and Reactivation.
abstract: Tuberculosis, caused by Mycobacterium tuberculosis, still remains a major global health problem. The main obstacle in eradicating this disease is the ability of this pathogen to remain dormant in macrophages, and then reactivate later under immuno-compromised conditions. The physiology of hypoxic nonreplicating M. tuberculosis is well-studied using many in vitro dormancy models. However, the physiological changes that take place during the shift from dormancy to aerobic growth (reactivation) have rarely been subjected to a detailed investigation. In this study, we developed an in vitro reactivation system by re-aerating the virulent laboratory strain of M. tuberculosis that was made dormant employing Wayne's dormancy model, and compared the proteome profiles of dormant and reactivated bacteria using label-free one-dimensional LC/MS/MS analysis. The proteome of dormant bacteria was analyzed at nonreplicating persistent stage 1 (NRP1) and stage 2 (NRP2), whereas that of reactivated bacteria was analyzed at 6 and 24 h post re-aeration. Proteome of normoxially grown bacteria served as the reference. In total, 1871 proteins comprising 47% of the M. tuberculosis proteome were identified, and many of them were observed to be expressed differentially or uniquely during dormancy and reactivation. The number of proteins detected at different stages of dormancy (764 at NRP1, 691 at NRP2) and reactivation (768 at R6 and 983 at R24) was very low compared with that of the control (1663). The number of unique proteins identified during normoxia, NRP1, NRP2, R6, and R24 were 597, 66, 56, 73, and 94, respectively. We analyzed various biological functions during these conditions. Fluctuation in the relative quantities of proteins involved in energy metabolism during dormancy and reactivation was the most significant observation we made in this study. Proteins that are up-regulated or uniquely expressed during reactivation from dormancy offer to be attractive targets for therapeutic intervention to prevent reactivation of latent tuberculosis.
authors.affiliation: From the ‡Mycobacterium Research Group, Rajiv Gandhi Centre for Biotechnology, Thycaud P.O., Thiruvananthapuram 695014, India;
authors.forename: Vipin
authors.initials: V
authors.lastname: Gopinath
authors.affiliation: From the ‡Mycobacterium Research Group, Rajiv Gandhi Centre for Biotechnology, Thycaud P.O., Thiruvananthapuram 695014, India;
authors.forename: Sajith
authors.initials: S
authors.lastname: Raghunandanan
authors.affiliation: From the ‡Mycobacterium Research Group, Rajiv Gandhi Centre for Biotechnology, Thycaud P.O., Thiruvananthapuram 695014, India;
authors.forename: Roshna Lawrence
authors.initials: RL
authors.lastname: Gomez
authors.affiliation: From the ‡Mycobacterium Research Group, Rajiv Gandhi Centre for Biotechnology, Thycaud P.O., Thiruvananthapuram 695014, India;
authors.forename: Leny
authors.initials: L
authors.lastname: Jose
authors.affiliation: §Mass Spectrometry and Proteomic Core Facility, Rajiv Gandhi Centre for Biotechnology, Thycaud P.O., Thiruvananthapuram 695014, India.
authors.forename: Arun
authors.initials: A
authors.lastname: Surendran
authors.affiliation: From the ‡Mycobacterium Research Group, Rajiv Gandhi Centre for Biotechnology, Thycaud P.O., Thiruvananthapuram 695014, India;
authors.forename: Ranjit
authors.initials: R
authors.lastname: Ramachandran
authors.affiliation: From the ‡Mycobacterium Research Group, Rajiv Gandhi Centre for Biotechnology, Thycaud P.O., Thiruvananthapuram 695014, India;
authors.forename: Akhil Raj
authors.initials: AR
authors.lastname: Pushparajan
authors.affiliation: From the ‡Mycobacterium Research Group, Rajiv Gandhi Centre for Biotechnology, Thycaud P.O., Thiruvananthapuram 695014, India;
authors.forename: Sathish
authors.initials: S
authors.lastname: Mundayoor
authors.affiliation: §Mass Spectrometry and Proteomic Core Facility, Rajiv Gandhi Centre for Biotechnology, Thycaud P.O., Thiruvananthapuram 695014, India.
authors.forename: Abdul
authors.initials: A
authors.lastname: Jaleel
authors.affiliation: From the ‡Mycobacterium Research Group, Rajiv Gandhi Centre for Biotechnology, Thycaud P.O., Thiruvananthapuram 695014, India; rakumar@rgcb.res.in.
authors.forename: Ramakrishnan Ajay
authors.initials: RA
authors.lastname: Kumar
mesh_terms: D000332:Aerobiosis; D001426:Bacterial Proteins / Q000378:metabolism*; D053858:Metabolic Networks and Pathways; D009169:Mycobacterium tuberculosis / Q000378:metabolism* / Q000502:physiology*; D016133:Polymerase Chain Reaction; D060066:Protein Interaction Maps; D020543:Proteome / Q000378:metabolism*; D040901:Proteomics / Q000379:methods*; D015203:Reproducibility of Results
chemical_list: D001426:Bacterial Proteins; D020543:Proteome