Genetic evidence that mycobacterial FtsZ and FtsW proteins interact, and colocalize to the division site inMycobacterium smegmatis

Abstract

We provide genetic evidence to show that the Mycobacterium tuberculosis FtsZ and FtsW proteins interact, and that these interactions are biologically relevant. Furthermore, we show by fluorescence microscopy that Mycobacterium smegmatis FtsW is part of its septasomal complex and colocalizes with FtsZ to the midcell sites. Colocalization experiments reveal that approximately 27% of the cells with septal Z-rings contain FtsW whereas 93% of the cells with FtsW bands are associated with FtsZ indicating that FtsW is late recruit to the septum, as in Escherichia coli. Our results suggest that mycobacterial FtsZ can localize to the septum independent of FtsW, and that interactions of FtsW with FtsZ are critical for the formation of productive FtsZ-rings and the cell division process in mycobacteria.

Septal Localization of the Mycobacterium tuberculosis MtrB Sensor Kinase Promotes MtrA Regulon Expression

“…Purification of FtsZ, MtrB, and MtrA Proteins-His-FtsZ TB , MBP fusion derivatives of MtrA WT , MtrA D13A , MtrA Y102C , soluble MtrB, MtrB H305D , and MtrB H305Y , and His-MtrA D13A were purified following the protocols as previously described (14,17). Preliminary experiments indicated that MBPMtrA D13A was not active, whereas His-MtrA D13A was active; hence, His-MtrA D13A was used to evaluate the promoter DNA binding experiments.…”

Characterization of CrgA, a New Partner of the Mycobacterium tuberculosis Peptidoglycan Polymerization Complexes

“…Accordingly, we examined FtsZ-GFP rings in the crgA mutant strain expressing Pami::ftsZ-gfp (Table 1, pJFR79). Using this construct FtsZ-GFP rings can be visualized in M. smegmatis without the addition of acetamide, and FtsZ levels increase by ϳ1.8-fold without any obvious cell division defects (42) (Fig. 3C and data not shown).…”

“…ChiZ, an M. tuberculosis cell wall hydrolase, is induced upon DNA damage and regulates midcell FtsZ assembly (7). M. tuberculosis FtsZ interacts with FtsW, and this interaction is implicated in providing stability to the FtsZ ring (13,42). Presumably, novel pathways are also involved in the regulation of M. tuberculosis cell division and cell wall synthesis.…”

Characterization of the mycobacterial chromosome segregation protein ParB and identification of its target in Mycobacterium smegmatis

“…Knowledge regarding the steps of the mycobacterial cell cycle (replication, chromosome segregation and cell division) seems to be critical for understanding the mechanisms that are responsible for the transition from an active to a non-replicative persistent state (and vice versa) of pathogenic mycobacteria, particularly M. tuberculosis. While initiation of chromosome replication Qin et al, 1999;Rajagopalan et al, 1995;Zawilak et al, 2004) and cell division (FtsZ ring formation) (Chauhan et al, 2006; Dziadek et al, 2002Dziadek et al, , 2003Huang et al, 2007;Rajagopalan et al, 2005) are relatively well studied in mycobacteria, nothing is known about the segregation of chromosomes in these bacteria.…”

“…Knowledge regarding the steps of the mycobacterial cell cycle (replication, chromosome segregation and cell division) seems to be critical for understanding the mechanisms that are responsible for the transition from an active to a non-replicative persistent state (and vice versa) of pathogenic mycobacteria, particularly M. tuberculosis. While initiation of chromosome replication Qin et al, 1999;Rajagopalan et al, 1995;Zawilak et al, 2004) and cell division (FtsZ ring formation) (Chauhan et al, 2006; Dziadek et al, 2002Dziadek et al, , 2003Huang et al, 2007;Rajagopalan et al, 2005) are relatively well studied in mycobacteria, nothing is known about the segregation of chromosomes in these bacteria.Bacterial chromosome segregation has been recently found to be an active and complex process closely coupled with replication (see Bartosik & Jagura-Burdzy, 2005;Errington et al, 2005;Hayes & Barilla, 2006; Leonard et al, 2005 for reviews). In bacteria studied to date, the newly synthesized origin (oriC) regions undergo a symmetric or asymmetric segregation process; two copies of the duplicated oriC regions migrate from the cell centre toward opposite cell poles, i.e.…”