scholarly journals NU-6027 Inhibits Growth of Mycobacterium tuberculosis by Targeting Protein Kinase D and Protein Kinase G

2019 ◽  
Vol 63 (9) ◽  
Author(s):  
Saqib Kidwai ◽  
Rania Bouzeyen ◽  
Sohini Chakraborti ◽  
Neha Khare ◽  
Sumana Das ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Protein Kinase ◽  
Docking Simulation ◽  
Health Concern ◽  
Protein Kinase G ◽  
Diagnostic Tools ◽  
Protein Kinase D ◽  
Content Type ◽  
Mouse Tissues ◽  
Pharmacologically Active

ABSTRACT Tuberculosis (TB) is a global health concern, and this situation has further worsened due to the emergence of drug-resistant strains and the failure of BCG vaccine to impart protection. There is an imperative need to develop highly sensitive, specific diagnostic tools, novel therapeutics, and vaccines for the eradication of TB. In the present study, a chemical screen of a pharmacologically active compound library was performed to identify antimycobacterial compounds. The phenotypic screen identified a few novel small-molecule inhibitors, including NU-6027, a known CDK-2 inhibitor. We demonstrate that NU-6027 inhibits Mycobacterium bovis BCG growth in vitro and also displayed cross-reactivity with Mycobacterium tuberculosis protein kinase D (PknD) and protein kinase G (PknG). Comparative structural and sequence analysis along with docking simulation suggest that the unique binding site stereochemistry of PknG and PknD accommodates NU-6027 more favorably than other M. tuberculosis Ser/Thr protein kinases. Further, we also show that NU-6027 treatment induces the expression of proapoptotic genes in macrophages. Finally, we demonstrate that NU-6027 inhibits M. tuberculosis growth in both macrophage and mouse tissues. Taken together, these results indicate that NU-6027 can be optimized further for the development of antimycobacterial agents.

scholarly journals Predictive Binding Affinity of Plant-Derived Natural Products Towards the Protein Kinase G Enzyme of Mycobacterium tuberculosis (MtPknG)

Plants ◽  
2019 ◽  
Vol 8 (11) ◽  
pp. 477 ◽  
Author(s):  
Qasaymeh ◽  
Rotondo ◽  
Oosthuizen ◽  
Lall ◽  
Seidel
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Protein Kinase ◽  
Medicinal Plants ◽  
Chemical Constituents ◽  
Efficiency Index ◽  
New Drugs ◽  
Health Concern ◽  
Protein Kinase G ◽  
Ligand Efficiency ◽  
Pelargonium Sidoides

Tuberculosis (TB), caused by Mycobacterium tuberculosis, is a growing public health concern worldwide, especially with the emerging challenge of drug resistance to the current drugs. Efforts to discover and develop novel, more effective, and safer anti-TB drugs are urgently needed. Products from natural sources, such as medicinal plants, have played an important role in traditional medicine and continue to provide some inspiring templates for the design of new drugs. Protein kinase G, produced by M. tuberculosis (MtPKnG), is a serine/threonine kinase, that has been reported to prevent phagosome-lysosome fusion and help prolong M. tuberculosis survival within the host’s macrophages. Here, we used an in silico, target-based approach (docking) to predict the interactions between MtPknG and 84 chemical constituents from two medicinal plants (Pelargonium reniforme and Pelargonium sidoides) that have a well-documented historical use as natural remedies for TB. Docking scores for ligands towards the target protein were calculated using AutoDock Vina as the predicted binding free energies. Ten flavonoids present in the aerial parts of P. reniforme and/or P. sidoides showed docking scores ranging from -11.1 to -13.2 kcal/mol. Upon calculation of all ligand efficiency indices, we observed that the (-G/MW) ligand efficiency index for flavonoids (4), (5) and (7) was similar to the one obtained for the AX20017 control. When taking all compounds into account, we observed that the best (-G/MW) efficiency index was obtained for coumaric acid, coumaraldehyde, p-hydroxyphenyl acetic acid and p-hydroxybenzyl alcohol. We found that methyl gallate and myricetin had ligand efficiency indices superior and equal to the AX20017 control efficiency, respectively. It remains to be seen if any of the compounds screened in this study exert an effect in M. tuberculosis-infected macrophages.

scholarly journals An Aspartate-Specific Solute-Binding Protein Regulates Protein Kinase G Activity To Control Glutamate Metabolism in Mycobacteria

mBio ◽  
2018 ◽  
Vol 9 (4) ◽  
Author(s):  
Nabanita Bhattacharyya ◽  
Irene Nailain Nkumama ◽  
Zaccheus Newland-Smith ◽  
Li-Ying Lin ◽  
Wen Yin ◽  
...  
Keyword(s):  
Amino Acids ◽  
Mycobacterium Tuberculosis ◽  
Amino Acid ◽  
Protein Kinase ◽  
Transmembrane Protein ◽  
Nutrient Utilization ◽  
Protein Kinase G ◽  
Structural Basis ◽  
Ligand Specificity ◽  
Content Type

ABSTRACTSignaling by serine/threonine phosphorylation controls diverse processes in bacteria, and identification of the stimuli that activate protein kinases is an outstanding question in the field. Recently, we showed that nutrients stimulate phosphorylation of the protein kinase G substrate GarA inMycobacterium smegmatisandMycobacterium tuberculosisand that the action of GarA in regulating central metabolism depends upon whether it is phosphorylated. Here we present an investigation into the mechanism by which nutrients activate PknG. Two unknown genes were identified as co-conserved and co-expressed with PknG: their products were a putative lipoprotein, GlnH, and putative transmembrane protein, GlnX. Using a genetic approach, we showed that the membrane protein GlnX is functionally linked to PknG. Furthermore, we determined that the ligand specificity of GlnH matches the amino acids that stimulate GarA phosphorylation. We determined the structure of GlnH in complex with different amino acid ligands (aspartate, glutamate, and asparagine), revealing the structural basis of ligand specificity. We propose that the amino acid concentration in the periplasm is sensed by GlnH and that protein-protein interaction allows transmission of this information across the membrane via GlnX to activate PknG. This sensory system would allow regulation of nutrient utilization in response to changes in nutrient availability. The sensor, signaling, and effector proteins are conserved throughout theActinobacteria, including the important human pathogenMycobacterium tuberculosis, industrial amino acid producerCorynebacterium glutamicum, and antibiotic-producingStreptomycesspecies.IMPORTANCETuberculosis (TB) kills 5,000 people every day, and the prevalence of multidrug-resistant TB is increasing in every country. The processes by which the pathogenMycobacterium tuberculosissenses and responds to changes in its environment are attractive targets for drug development. Bacterial metabolism differs dramatically between growing and dormant cells, and these changes are known to be important in pathogenesis of TB. Here, we used genetic and biochemical approaches to identify proteins that allowM. tuberculosisto detect amino acids in its surroundings so that it can regulate its metabolism. We have also shown how individual amino acids are recognized. The findings have broader significance for other actinobacterial pathogens, such as nontuberculous mycobacteria, as well asActinobacteriaused to produce billions of dollars of amino acids and antibiotics every year.

scholarly journals Correction: Key residues in Mycobacterium tuberculosis protein kinase G play a role in regulating kinase activity and survival in the host.

2020 ◽  
Vol 295 (7) ◽  
pp. 2135-2135
Author(s):  
Divya Tiwari ◽  
Rajnish Kumar Singh ◽  
Kasturi Goswami ◽  
Sunil Kumar Verma ◽  
Balaji Prakash ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Protein Kinase ◽  
Kinase Activity ◽  
Protein Kinase G ◽  
Key Residues

scholarly journals Mouse Bone Marrow Sca-1+ CD44+ Mesenchymal Stem Cells Kill Avirulent Mycobacteria but Not Mycobacterium tuberculosis through Modulation of Cathelicidin Expression via the p38 Mitogen-Activated Protein Kinase-Dependent Pathway

2017 ◽  
Vol 85 (10) ◽  
Author(s):  
Sumanta Kumar Naik ◽  
Avinash Padhi ◽  
Geetanjali Ganguli ◽  
Srabasti Sengupta ◽  
Sanghamitra Pati ◽  
...  
Keyword(s):  
Stem Cells ◽  
Bone Marrow ◽  
Mesenchymal Stem Cells ◽  
Mycobacterium Tuberculosis ◽  
Protein Kinase ◽  
Nuclear Translocation ◽  
Mitogen Activated Protein Kinase ◽  
Content Type ◽  
Expression Levels ◽  
Mitogen Activated Protein

ABSTRACT Mycobacterium tuberculosis primarily infects lung macrophages. However, a recent study showed that M. tuberculosis also infects and persists in a dormant form inside bone marrow mesenchymal stem cells (BM-MSCs) even after successful antibiotic therapy. However, the mechanism(s) by which M. tuberculosis survives in BM-MSCs is still not known. Like macrophages, BM-MSCs do not contain a well-defined endocytic pathway, which is known to play a central role in the clearance of internalized mycobacteria. Here, we studied the fate of virulent and avirulent mycobacteria in Sca-1+ CD44+ BM-MSCs. We found that BM-MSCs were able to kill avirulent Mycobacterium smegmatis and Mycobacterium bovis BCG but not the pathogenic species M. tuberculosis. Further mechanistic studies revealed that pathogenic M. tuberculosis dampens the antibacterial response of BM-MSCs by downregulating the expression of the cationic antimicrobial peptide cathelicidin. In contrast, avirulent mycobacteria were effectively killed by inducing the Toll-like receptor 2/4 (TLR2/4) pathway-dependent expression of cathelicidin, while small interfering RNA (siRNA)-mediated cathelicidin silencing increased the survival of M. bovis BCG in BM-MSCs. We also showed that M. bovis BCG infection caused increased expression levels of MyD88, phospho-interleukin-1 receptor-associated kinase 4 (pIRAK-4), and the p38 mitogen-activated protein kinase (MAPK) signaling pathway. Further downstream investigations demonstrated that IRAK-4–p38 activation increased the nuclear translocation of NF-κB, which subsequently induced the expression of cathelicidin and the cytokine interleukin-1β (IL-1β), resulting in the decreased survival of M. bovis BCG. On the other hand, inhibition of TLR2/4, pIRAK-4, p38, and NF-κB nuclear translocation decreased cathelicidin and IL-1β expression levels and therefore increased the survival of avirulent mycobacteria. This is the first report that demonstrates that virulent mycobacteria manipulate the TLR2/4–MyD88–IRAK-4–p38–NF-κB–Camp–IL-1β pathway to survive inside bone marrow stem cells.

scholarly journals IgG response to Mycobacterium tuberculosis non-polar lipids and sonicated extracts among tuberculous meningitis patients

2020 ◽  
Vol 2 (7) ◽  
Author(s):  
Prashant Giribhattanavar ◽  
Chris Pirson ◽  
Kavitha Kumar ◽  
Manaf Al-Qahtani ◽  
Ravi Shankar ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Sensitivity And Specificity ◽  
Tuberculous Meningitis ◽  
Laboratory Diagnosis ◽  
Elisa Test ◽  
Polar Lipids ◽  
Health Concern ◽  
Full Potential ◽  
Content Type ◽  
Different Populations

Introduction. The diagnosis of tuberculous meningitis (TBM) is a major global health concern due to its protean nature. There is a need to identify better biomarkers for the rapid and definitive diagnosis of TBM. Lipids have been poorly explored as diagnostic markers in TBM. Aim. Non-polar lipids (NPL) and mycobacterial sonicate extract (MTSE) antigens were assessed for diagnosis of Mycobacterium tuberculosis . Methodology. A total of 110 cerebrospinal fluid samples were categorized as confirmed, suspected and non-TBM cases according to clinical presentation and laboratory investigations, which were further analysed by NPL and MTSE ELISA. Results. The sensitivity and specificity of the NPL ELISA were 39.6 and 96 %, respectively, whereas the MTSE ELISA was 17 % sensitive and 92 % specific. The combination of the NPL and MTSE ELISA test was superior to these tests alone, with sensitivity and specificity of 43 and 88 %, respectively. Conclusion. This combination may be useful as an adjunct in the laboratory diagnosis of TBM. However, future studies in different settings among different populations, such as those with human immunodeficiency virus co-infection, are desirable to explore the full potential of biomarkers.

Sclerotiorin inhibits protein kinase G from Mycobacterium tuberculosis and impairs mycobacterial growth in macrophages

Tuberculosis ◽  
2017 ◽  
Vol 103 ◽  
pp. 37-43 ◽  
Author(s):  
Dongni Chen ◽  
Shuangshuang Ma ◽  
Lei He ◽  
Peibo Yuan ◽  
Zhigang She ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Protein Kinase ◽  
Protein Kinase G ◽  
Mycobacterial Growth
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