Open AccessPknH, a transmembrane Hank's type serine/threonine kinase from Mycobacterium tuberculosis is differentially expressed under stress conditions
Author(s) -
Sharma Kirti,
Chandra Harish,
Gupta Pradeep K.,
Pathak Monika,
Narayan Azeet,
Meena Laxman S.,
D'Souza Rochelle C.J.,
Chopra Puneet,
Ramachandran S.,
Singh Yogendra
Publication year - 2004
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1016/j.femsle.2004.01.045
Subject(s) - kinase , biology , transmembrane protein , protein kinase a , biochemistry , serine , c raf , threonine , map2k7 , protein kinase c , phosphorylation , heat shock protein , microbiology and biotechnology , mitogen activated protein kinase kinase , cyclin dependent kinase 2 , gene , receptor
Serine/threonine protein kinases (STPKs) represent a burgeoning concept in prokaryotic signaling and have been implicated in a range of control mechanisms. This paper describes the enzymatic and molecular characterization of PknH, a mycobacterial STPK. After cloning and expression as a Glutathione‐ S ‐transferase fusion protein in E. coli , PknH was found to phosphorylate itself and exogenous substrates like myelin basic protein and histone. The kinase activity of PknH was inhibited by the kinase inhibitors staurosporine and H‐7. The results confirmed that PknH is a transmembrane protein and is restricted to members of the Mycobacterium tuberculosis complex. In addition, transcriptional analysis of pknH in M. tuberculosis under various stress conditions revealed that exposure to low pH and heat shock decreased the level of pknH transcription significantly. This is the first report describing differential expression of a mycobacterial kinase in response to stress conditions which can indicate its ability to regulate cellular events promoting bacterial adaptation to environmental change.