Srivastava, K. K. | Search bioRxiv

bioRxiv2023

A brief report on the of mycobacterial proteins regulated by the loss of PtkA in Mtb-H37Ra

Kinase-phosphatase signaling plays an important role in cellular signaling pathways. The genome of Mycobacterium tuberculosis, (the causative agent of tuberculosis), is embossed with several kinases and phosphatases. Recently identified protein tyrosine kinase (PtkA) is a novel tyrosine kinase that phosphorylates protein tyrosine phosphatase A (PtpA) and regulates its secretion in the cytosol. PtkA is considered as a regulatory protein. In this study, the mycobacterial proteins regulated due to the ptkA gene deletion in Mtb-H37Ra have been studied and highlighted using two-dimensional (2D) gel electrophoresis coupled with MALDI TOF MS/MS analysis. We have identified 13 differentially expressed proteins that play an important role in mycobacterial intracellular survival and pathogenesis.

microbiology↗

bioRxiv2021

Protein kinase J regulates Rv0642c expression and sensitivity to rifampicin of mycobacteria

Mycobacterium tuberculosis (M.tb) persists for long-duration inside the human host in both active and latent form by modulating the immune response. The mechanisms employed by M.tb to survive inside the host and evade the host immune system need to be explored in greater depth for the rational design of novel treatment strategies. The phosphorylation and methylation of biomolecules need to be addressed in mycobacteria because it has an important role in infection establishment and persistence. In the present study, we elaxborate on the role of PknJ in the slow growth of BCG and its association with mmaA4 protein during extracellular and intracellular growth. The pknJ knock-out (KO) BCG has been used to decode the functional significance in mycobacteria. The mmaA4 expression and methyltransferase activity is decreased in knocked-out BCG strain (pknJ-/-) during extracellular growth, while mmaA4 expression and methyltransferase activity is increased during intracellular growth of mycobacteria. The knocked-out BCG strain is highly sensitive to the rifampicin antibiotics during extracellular growth in compared to control. A significant association of pknJ and mmaA4 was found in our studies during the growth and intracellular persistence of mycobacteria.

microbiology↗