K J Downing1, J C Betts, D I Young, R A McAdam, F Kelly, M Young, V Mizrahi. 1. MRC/NHLS/WITS Molecular Mycobacteriology Research Unit, School of Pathology of the University of the Witwatersrand and the National Health Laboratory Service, P.O. Box 1038, Johannesburg 2000, South Africa.
Abstract
SETTING: Aged, dormant cultures of Mycobacterium tuberculosis can be resuscitated by a secreted, proteinaceous growth factor from Micrococcus luteus, known as resuscitation-promoting factor (Rpf). M. tuberculosis contains five rpf-like genes, rpfA (Rv0867c), rpfB (Rv1009), rpfC (Rv1884c), rpfD (Rv2389c) and rpfE (Rv2450c), that bear significant similarity to Mi. luteus rpf, suggesting that these too may play a role in growth and/or reactivation from a quiescent state. OBJECTIVE AND DESIGN: Unmarked deletion mutants of each of the five rpf-like genes of M. tuberculosis H37Rv were constructed and their phenotypes and global gene expression profiles were assessed. RESULTS AND CONCLUSIONS: Deletion of any one of the rpf-like genes did not affect growth or survival of M. tuberculosis in liquid culture, but some alterations in colony-forming ability and colonial morphology were observed. Global gene expression profiling suggested that loss of rpfC affected the expression of the largest number of genes and there was a significant overlap in the differential gene expression profile of the rpfC mutant with those of the rpfB, rpfD and rpfE mutants. The expression profile of the rpfA mutant was notably less similar, but inverse associations with genes affected in the other mutants were observed. These results, together with those obtained by real-time, quantitative RT-PCR, suggest that the rpf-like genes serve wholly or partially overlapping functions in M. tuberculosis.
SETTING: Aged, dormant cultures of Mycobacterium tuberculosis can be resuscitated by a secreted, proteinaceous growth factor from Micrococcus luteus, known as resuscitation-promoting factor (Rpf). M. tuberculosis contains five rpf-like genes, rpfA (Rv0867c), rpfB (Rv1009), rpfC (Rv1884c), rpfD (Rv2389c) and rpfE (Rv2450c), that bear significant similarity to Mi. luteus rpf, suggesting that these too may play a role in growth and/or reactivation from a quiescent state. OBJECTIVE AND DESIGN: Unmarked deletion mutants of each of the five rpf-like genes of M. tuberculosis H37Rv were constructed and their phenotypes and global gene expression profiles were assessed. RESULTS AND CONCLUSIONS: Deletion of any one of the rpf-like genes did not affect growth or survival of M. tuberculosis in liquid culture, but some alterations in colony-forming ability and colonial morphology were observed. Global gene expression profiling suggested that loss of rpfC affected the expression of the largest number of genes and there was a significant overlap in the differential gene expression profile of the rpfC mutant with those of the rpfB, rpfD and rpfE mutants. The expression profile of the rpfA mutant was notably less similar, but inverse associations with genes affected in the other mutants were observed. These results, together with those obtained by real-time, quantitative RT-PCR, suggest that the rpf-like genes serve wholly or partially overlapping functions in M. tuberculosis.
Authors: Katrina J Downing; Vladimir V Mischenko; Margarita O Shleeva; Danielle I Young; Michael Young; Arseny S Kaprelyants; Alexander S Apt; Valerie Mizrahi Journal: Infect Immun Date: 2005-05 Impact factor: 3.441
Authors: Dany J V Beste; Mateus Espasa; Bhushan Bonde; Andrzej M Kierzek; Graham R Stewart; Johnjoe McFadden Journal: PLoS One Date: 2009-04-28 Impact factor: 3.240
Authors: Sebastian D Schuck; Henrik Mueller; Frank Kunitz; Albert Neher; Harald Hoffmann; Kees L C M Franken; Dirk Repsilber; Tom H M Ottenhoff; Stefan H E Kaufmann; Marc Jacobsen Journal: PLoS One Date: 2009-05-18 Impact factor: 3.240