Mycobacterium tuberculosis ftsZ expression and minimal promoter activity

Abstract

SUMMARY Optimal levels of ftsZ gene product are shown to be required for initiation of the cell division process in Mycobacterium tuberculosis. Here, we report that the ftsZ gene expression is sharply down-regulated during starvation and hypoxia, conditions that are believed to result in growth arrest, but is restored upon dilution of cultures into fresh oxygen-rich media. Primer extension analysis identified four transcriptional start sites, designated as P1, P2, P3 and P4 at nucleotide positions −43, −101, −263, and −787, respectively, in the immediate upstream flanking region of the ftsZ initiation codon. Promoter deletion and homologous recombination experiments revealed that ftsZ expression from the 101-bp region is sufficient for M. tuberculosis viability. All promoter strains had reduced FtsZ levels compared to wild-type, although the loss of P4 severely compromised FtsZ levels during both the active and stationary phases. We propose that ftsZ expression from all promoters is required for optimal intracellular FtsZ levels and that the activities of P4 and possibly other promoters are down-regulated during growth arrest conditions.

Asymmetric growth and division in Mycobacterium spp.: compensatory mechanisms for non‐medial septa

“…Intense investigations into cell division mechanisms and its control for several decades with elegant microscopy techniques made possible by unprecedented developments of fluorescent probes have revealed some astonishing details about divisome assembly and cytokinesis in model rod‐shaped bacteria (see for reviews: Rothfield et al ., ; Harry et al ., ; Margolin, ; Bramkamp and Baarle, ; Wu and Errington, ). However, despite many recent studies on divisome assembly in Mycobacterium spp., the mechanism controlling its division site placement remains uncharacterized (Datta et al ., ; ; Dziadek et al ., ; Kang et al ., ; Rajagopalan et al ., ; Thanky et al ., ; Kiran et al ., ; Maloney et al ., ; Oleferenko et al ., ; Sureka et al ., ; Plocinski et al ., ). The components of the division machinery and their assembly at the Z‐ring in Mycobacterium spp.…”

“…uncharacterized (Datta et al, 2002;2006;Dziadek et al, 2003;Kang et al, 2005;Rajagopalan et al, 2005;Thanky et al, 2007;Kiran et al, 2009;Maloney et al, 2009;Oleferenko et al, 2009;Sureka et al, 2010;Plocinski et al, 2011). The components of the division machinery and their assembly at the Z-ring in Mycobacterium spp.…”

Characteristics of the essential pathogenicity factor Rv1828, a MerR family transcription regulator from Mycobacterium tuberculosis

“…The Rv2150c encodes for FtsZ protein and is shown to be involved in cell division of bacteria . In fact, the promoter region of Rv2150c contains four transcriptional start sites, namely, P1, P2, P3 and P4 and it has been shown that all four sites are important for the expression of FtsZ . Among the four start sites, the P1 site shows binding with Rv1828.…”

Bacterial Cell Division: Nonmodels Poised to Take the Spotlight

“…Several studies reported that the transcription factor-like WhiB homologs may be involved in the non-transcriptional regulation of cell division in Mycobacteria by either directly interacting with FtsZ or acting as a chaperone, depending on the species (11, 54, 77). Furthermore, there is evidence that ftsZ levels could be up- or down-regulated for adapting to various extracellular environments (74). Regulation of cell division in non-pathogenic Mycobacterium smegmatis may harbor a largely similar cell division regulation system as M. tuberculosis , since M. smegmatis ftsZ can complement the deletion of ftsZ in M. tuberculosis (36).…”