Article

Coupled, circumferential motions of the cell wall synthesis machinery and MreB filaments in B. subtilis. Science

Department of Systems Biology, Harvard Medical School, Boston, MA 02115, USA.
Science (Impact Factor: 31.48). 06/2011; 333(6039):222-5. DOI: 10.1126/science.1203285
Source: PubMed

ABSTRACT Rod-shaped bacteria elongate by the action of cell wall synthesis complexes linked to underlying dynamic MreB filaments. To understand how the movements of these filaments relate to cell wall synthesis, we characterized the dynamics of MreB and the cell wall elongation machinery using high-precision particle tracking in Bacillus subtilis. We found that MreB and the elongation machinery moved circumferentially around the cell, perpendicular to its length, with nearby synthesis complexes and MreB filaments moving independently in both directions. Inhibition of cell wall synthesis by various methods blocked the movement of MreB. Thus, bacteria elongate by the uncoordinated, circumferential movements of synthetic complexes that insert radial hoops of new peptidoglycan during their transit, possibly driving the motion of the underlying MreB filaments.

Download full-text

Full-text

Available from: Ethan Clark Garner, Dec 28, 2013
1 Follower
 · 
204 Views
  • Source
    • "After interaction with MreB, the Agl–Glt machinery together with MglA-GTP and MreB would become active and move directionally along its elusive track toward the lagging cell pole. It is unlikely that MreB itself forms the track because MreB does not appear to make continuous and polarized filaments in bacterial cells (Domínguez-Escobar et al., 2011; Garner et al., 2011; van Teeffelen et al., 2011) but instead MreB could act as a protein scaffold for assembly of the motility machinery. Recently, Nan et al. (2015) further suggested that MglA also regulates the directionality of the Agl motor; whether this is linked to the interaction with MreB remains to be explored. "
    The Journal of Cell Biology 07/2015; · 9.69 Impact Factor
  • Source
    • "For localization to the cell wall, LytE interacts with the cytoskeletal protein MreBH (Carballido-López et al., 2006; Domínguez-Cuevas et al., 2013), of which the expression is downregulated in retentostat 2 only. Furthermore , the transcriptome revealed the repression in both retentostats of the genes mreD and rodZ which are part of the cell wall biosynthetic complex and involved in morphogenesis (Domínguez-Escobar et al., 2011; Garner et al., 2011; Muchová et al., 2013). "
    [Show abstract] [Hide abstract]
    ABSTRACT: Nutrient scarcity is a common condition in nature, but the resulting extremely low growth rates (below 0.025 h-1) are an unexplored research area in B. subtilis. To understand microbial life in natural environments, studying the adaptation of B. subtilis to near-zero growth conditions is relevant. To this end, a chemostat modified for culturing an asporogenous B. subtilis sigF mutant strain at extremely low growth rates (also named a retentostat) was set up and biomass accumulation, culture viability, metabolite production and cell morphology were analysed. During retentostat culturing the specific growth rate decreased to a minimum of 0.00006 h-1, corresponding to a doubling time of 470 days. The energy distribution between growth- and maintenance-related processes showed that a state of near-zero growth was reached. Remarkably, a filamentous cell morphology emerged, suggesting that cell separation is impaired under near-zero growth conditions. To evaluate the corresponding molecular adaptations to extremely low specific growth, transcriptome changes were analysed. These revealed that cellular responses to near-zero growth conditions share several similarities with those of cells during the stationary phase of batch-growth. However, fundamental differences between these two non-growing states are apparent by their high viability and absence of stationary phase mutagenesis under near-zero growth conditions.
    Environmental Microbiology 10/2014; 17(2). DOI:10.1111/1462-2920.12676 · 6.24 Impact Factor
  • Source
    • "However, some recent reports using high-resolution imaging indicate that either in E. coli or in B. subtilis MreB filaments do not run the length of the cell2122. Instead, they are actually composed of small dynamic patches that move around the cell circumference and are driven by the cell wall synthesis machinery472122232425. "
    [Show abstract] [Hide abstract]
    ABSTRACT: In eukaryotes, the manipulation of the host actin cytoskeleton is a necessary strategy for viral pathogens to invade host cells. Increasing evidence indicates that the actin homolog MreB of bacteria plays key roles in cell shape formation, cell polarity, cell wall biosynthesis, and chromosome segregation. However, the role of bacterial MreB in the bacteriophage infection is not extensively investigated. To address this issue, in this study, the MreB of thermophilic Geobacillus sp. E263 from a deep-sea hydrothermal field was characterized by inhibiting the MreB polymerization and subsequently evaluating the bacteriophage GVE2 infection. The results showed that the host MreB played important roles in the bacteriophage infection at high temperature. After the host cells were treated with small molecule drug A22 or MP265, the specific inhibitors of MreB polymerization, the adsorption of GVE2 and the replication of GVE2 genome were significantly repressed. The confocal microscopy data revealed that MreB facilitated the GVE2 infection by inducing the polar distribution of virions during the phage infection. Our study contributed novel information to understand the molecular events of the host in response to bacteriophage challenge and extended our knowledge about the host-virus interaction in deep-sea vent ecosystems.
    Scientific Reports 04/2014; 4:4823. DOI:10.1038/srep04823 · 5.58 Impact Factor
Show more