PknE, a serine/threonine protein kinase from Mycobacterium tuberculosis has a role in adaptive responses
Serine/threonine protein kinases (STPK) play a major role in the physiology and pathogenesis of Mycobacterium tuberculosis. Here, we have examined the role of pknE, a STPK in the adaptive responses of M. tuberculosis using a deletion mutant ΔpknE. The survival of ΔpknE was assessed in the presence of stress (pH, surfactant and cell wall–damaging agents) and anti-tuberculosis drugs. ΔpknE had a defective growth in pH 7.0 and lysozyme (a cell wall–damaging agent) with better survival in pH 5.5, SDS and kanamycin (a second-line anti-tuberculosis drug). Furthermore, ΔpknE was reduced in cell size during growth in liquid media and exhibited hypervirulence in a guinea pig model of infection. In conclusion, our data suggest that pknE plays a role in adaptive response of M. tuberculosis regulating cellular integrity and survival.
KeywordsMycobacterium tuberculosis STPK PknE and stress
Mr. Dinesh kumar is a recipient of ICMR-SRF fellowship. We thank posthumously late Ms. Nalini Sunder Mohan, Dept of Bacteriology, NIRT for her help in drug sensitivity assay. We thank Dr. Lily Therese, Professor and Head, Dept of Microbiology and Mrs Uma Maheshwari, Sankara Nethralaya for their help with DIC images. We thank Mr. Chandran, Department of Clinical Pathology, NIRT for his help in animal experiments.
Conflict of interest
No funds were received except ICMR-SRF fellowship to Mr. Dinesh Kumar.
- Kumar D, Narayanan S (2012) pknE, a serine/threonine kinase of Mycobacterium tuberculosis modulates multiple apoptotic paradigms. Infect Genet Evol 12(4):737–747Google Scholar
- Malhotra V, Arteaga-Cortes LT, Clay G, Clark-Curtiss JE (2010) Mycobacterium tuberculosis protein kinase K confers survival advantage during early infection in mice and regulates growth in culture and during persistent infection: implications for immune modulation. Microbiology 156:2829–2841PubMedCrossRefGoogle Scholar
- Pal S, Dolai S, Yadav RK, Adak S (2010) Ascorbate peroxidase from Leishmania major controls the virulence of infective stage of promastigotes by regulating oxidative stress. PLoS One 5:e11271Google Scholar