Transcription profiling by array of overexpression of the Rv0805 phosphodiesterase elicits a cAMP-independent transcriptional response

ABSTRACT: The Rv0805 gene in Mycobacterium tuberculosis encodes a metallophosphoesterase which shows cAMP-hydrolytic activity. Overexpression of Rv0805 has been used as a tool to lower intracellular cAMP levels and thereby elucidate the roles of cAMP in mycobacteria. Here we show that levels of cAMP in M. tuberculosis were lowered by only .30% following overexpression of Rv0805, and transcript levels of a number of genes, which include those associated with virulence and the methyl citrate cycle, were altered. The genes that showed altered expression were distinct from those differentially regulated in a strain deleted for the cAMP-receptor protein (CRP(Mt)), consistent with the relatively low dependence on cAMP of CRP(Mt) binding to DNA. Using mutants of Rv0805 we show that the transcriptional signature of Rv0805 overexpression is a combination of catalysis-dependent and independent effects, and that the structurally flexible C-terminus of Rv0805 is crucial for the catalysis-independent effects of the protein. Our study demonstrates the dissociation of Rv0805 and cAMP-regulated gene expression, and reveals alternate functions for this phosphodiesterase from M. tuberculosis. [Data is also available from http://bugs.sgul.ac.uk/E-BUGS-146]

ORGANISM(S): Mycobacterium tuberculosis

SUBMITTER: Adam Witney 

PROVIDER: E-BUGS-146 | biostudies-arrayexpress |

REPOSITORIES: biostudies-arrayexpress