Involvement of Serine Threonine Protein Kinase, PknL, from Mycobacterium Tuberculosis H37Rv in Starvation Response of Mycobacteria

Abstract

The adaptation to nutrient depletion in bacteria involves a highly organized series of intracellular events that enable them to adapt to starvation conditions. The regulatory effect of serine threonine protein kinase, PknL, from Mycobacterium tuberculosis strain H 37 Rv was investigated under nutrient deprived conditions that simulate circumstances leading to latency. Recombinant PknL was expressed in Mycobacterium smegmatis strain mc 2 155 in its wild type and mutant forms. In vitro growth kinetics experiments revealed that clone expressing active PknL had a significant growth advantage under nutrient limiting conditions. Experiments were conducted to ascertain the in silico predictions of the involvement of PknL in regulating glutamine metabolism in mycobacteria. Furthermore, a role for PknL in cell wall biogenesis/cell division was shown by scanning electron microscopy.

Phosphoproteomics analysis of a clinical Mycobacterium tuberculosis Beijing isolate: expanding the mycobacterial phosphoproteome catalog

“…Of the phosphorylated STPKs, PknA, PknB, and PknG have been shown to be essential for in vitro growth (Sassetti et al, 2003 ) and to regulate cell growth and cell division and interfere with host signaling pathways (Fernandez et al, 2006 ). PknE, PknH, PknJ, and PknL have been implicated in the adaptation to the extracellular environment or intracellular survival of M. tuberculosis (Sharma et al, 2006 ; Lakshminarayan, 2009 ; Arora et al, 2010 ; Parandhaman et al, 2014 ) which is in agreement with reports that during early growth the bacilli undergo a period of adaptation to their external environment (Stock et al, 1989 ; Soares et al, 2013 ). PknE is involved in the suppression of apoptosis during nitrate stress (Kumar and Narayanan, 2012 ) and intracellular survival and adaptation to hostile environments (Parandhaman et al, 2014 ).…”

Regulation of transcription by eukaryotic-like serine-threonine kinases and phosphatases in Gram-positive bacterial pathogens

“…Although the exact inducing signal for PknL has yet to be determined, evidence suggests a role similar to that of PknA and PknB in cell wall associated functions, as well as the regulation of glutamine metabolism. 124 An available structure of the PknL substrate Rv2175c reveals a surprising OmpR-like TCS winged helix-turnhelix (wHTH) DNA binding motif that is missing its typical third helix, a structural phenomenon usually only observed in phage-derived transcription factors. The wHTH is preceded by a flexible and disordered 16-residue long N-terminus that contains Thr9.…”

Role of Diabetes in prevalence of Tuberculosis

“…It can survive in a dry state for weeks and can withstand weak disinfectants. Usually the bacterium can grow within the cells of a host organism, but M. tuberculosis can be cultured and grown in vitro [5]. A person gets infected with tuberculosis bacteria when he or she inhales small minute particles of infected phlegm or sputum from the air.…”