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Unveiling the Novel Dual Specificity Protein Kinases in Bacillus anthracis

Authors :
Anshika Singhal
Andaleeb Sajid
Mary Diana Arulanandh
Souvik Maiti
Andrei P. Pomerantsev
Yogendra Singh
Stephen H. Leppla
Gunjan Arora
Abid R. Mattoo
Source :
Journal of Biological Chemistry. 287:26749-26763
Publication Year :
2012
Publisher :
Elsevier BV, 2012.

Abstract

Dual specificity protein kinases (DSPKs) are unique enzymes that can execute multiple functions in the cell, which are otherwise performed exclusively by serine/threonine and tyrosine protein kinases. In this study, we have characterized the protein kinases Bas2152 (PrkD) and Bas2037 (PrkG) from Bacillus anthracis. Transcriptional analyses of these kinases showed that they are expressed in all phases of growth. In a serendipitous discovery, both kinases were found to be DSPKs. PrkD was found to be similar to the eukaryotic dual specificity Tyr phosphorylation-regulated kinase class of dual specificity kinases, which autophosphorylates on Ser, Thr, and Tyr residues and phosphorylates Ser and Thr residues on substrates. PrkG was found to be a bona fide dual specificity protein kinase that mediates autophosphorylation and substrate phosphorylation on Ser, Thr, and Tyr residues. The sites of phosphorylation in both of the kinases were identified through mass spectrometry. Phosphorylation on Tyr residues regulates the kinase activity of PrkD and PrkG. PrpC, the only known Ser/Thr protein phosphatase, was also found to possess dual specificity. Genistein, a known Tyr kinase inhibitor, was found to inhibit the activities of PrkD and PrkG and affect the growth of B. anthracis cells, indicating a possible role of these kinases in cell growth and development. In addition, the glycolytic enzyme pyruvate kinase was found to be phosphorylated by PrkD on Ser and Thr residues but not by PrkG. Thus, this study provides the first evidence of DSPKs in B. anthracis that belong to different classes and have different modes of regulation.

Details

ISSN :
00219258
Volume :
287
Database :
OpenAIRE
Journal :
Journal of Biological Chemistry
Accession number :
edsair.doi...........ea08ebfad48707284a89b2b3f977a6f9
Full Text :
https://doi.org/10.1074/jbc.m112.351304