Expression and characterization of the Mycobacterium tuberculosis serine/threonine protein kinase PknB.
PknB is a member of the newly discovered eukaryotic-like protein serine/threonine kinase (PSTK) family of proteins. The pknB gene was cloned and expressed in Escherichia coli. The active recombinant protein was purified and shown to be reactive with antiphosphoserine antibodies, as well as with antibodies to the phosphorylated eukaryotic Ser/Thr kinases mitogen-activated protein kinase kinase 3 and 6, P38, and Creb. In vitro kinase assays demonstrated that PknB is a functional kinase that is autophosphorylated on serine/threonine residues and is also able to phosphorylate the peptide substrate myelin basic protein. Analysis of pknB expression in Mycobacterium tuberculosis indicates the presence of pknB mRNA in (i) organisms grown in vitro in bacteriological media, (ii) a murine macrophage in vitro infection model, and (iii) in vivo alveolar macrophages from a patient with tuberculosis.
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Department of Medicine, Division of Infectious Diseases, University of British Columbia, Vancouver, British Columbia, Canada V5Z 3J5. yossi@interchange.ubc.ca
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Drews
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D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D002460:Cell Line; D003001:Cloning, Molecular; D006801:Humans; D016676:Macrophages, Alveolar / Q000382:microbiology; D051379:Mice; D009169:Mycobacterium tuberculosis / Q000201:enzymology*; D010766:Phosphorylation; D017346:Protein Serine-Threonine Kinases / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D011518:Proto-Oncogene Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D051057:Proto-Oncogene Proteins c-akt; D014376:Tuberculosis / Q000378:metabolism
D001426:Bacterial Proteins; D011518:Proto-Oncogene Proteins; D017346:Protein Serine-Threonine Kinases; D051057:Proto-Oncogene Proteins c-akt