Team:Newcastle/Filamentous Cells
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Filamentous Cells
YneA
SOS response is believe to be a universal bacteria phenomenon first studied in E.coli -LexA, recA |
In Bacillus subtillis (gram positive) dinR protein is homologous to lexA (Repressor of din-damage inducible genes). din genes include uvrA, uvrB, dinB, dinC dinR and recA. DNA damage inhibits cell division. |
Wild type Bacillus subtillis |
dinR KO |
dinR KO mutant over expressed the divergent (opposite direction) transcript for YneA, YneB and YnzC. These genes form the SOS regulon (recA independent SOS response) |
YneA suppressed in wt without SOS induction |
Expression of YneA from IPTG controlled promoter in wt leads to elongation. |
Disruption of YneA in SOS response leads to reduced elongation. Altering YneB and YnzC expression does not affect cell morphology. |
Double mutant (dinR YneA) |
YneA protein required to suppress cell division. Not chromosome replication or segregation. |
FtsZ is important for bacterial cell division forming a ring structure at the division site by polymerising
assembling other proteins necessary for division at the site. |
FtsZ localises to the cell division cycle unless dinR is disrupted or YneA is being induced. |
YneA suppresses FtsZ ring formation- no proven direct interaction by two-hybrid. |
Filamentous cells less colony formation. |
YneA expression via the inactivation of dinR by Rec A is important. |
Sequence of YneA: http://www.ncbi.nlm.nih.gov/nuccore/NC_000964.3?from=1918391&to=1918738&report=graph&content=5 |
Kawai, Y., Moriya, S., & Ogasawara, N. (2003). Identification of a protein, YneA, responsible for cell division suppression during the SOS response in Bacillus subtilis. Molecular microbiology, 47(4), 1113-22. Retrieved from http://www.ncbi.nlm.nih.gov/pubmed/12581363.
MinCDJ
In B.subtilis cell division occurs precisely mid cell via the formation of the FtsZ ring (tubulin homologue), through Noc (Nucleoid occlusion: prevents division over nucleoids) and the min system (well described in E.coli), which prevents division taking place at the ends of the cell (poles). |
Main function of Min system to prevent mini cell formation and ensuring only one cell division occurs per cell cycle. |
Min’s role is not just in the inhibition of FtsZ. FtsZ recruits other components causing synthesis of the new wall and cell invagination. |
Cell division is regulated spatially and temporally. |
Min C inhibits FtsZ ring formation; Min C interacts with Min D via its C-terminal domain. Min C inhibits lateral interaction between the filaments. |
Min D is a membrane associated ATPase. (Min E ensures high concentrations of MinCD at the poles in E.coli, no Min E homologue in B.subtilis! Instead DivIVA acts as a topological factor). |
Min C in B.subtilis is responsible for localisation (shown using GFP) showed a primary site of localisation at the site of active division challenging the original model for the role of Min. |
Min J was discovered linking Min D to DivIVA and therefore necessary for localisation. |
Over expression of Min D in the absence of Min J causes lethal filamentation. |
Min C sequence |
http://www.ncbi.nlm.nih.gov/nuccore/NC_000964.3?from=2858550&to=2859298&strand=true&report=graph&content=5 |
http://www.ncbi.nlm.nih.gov/gene/937500 |
MinD sequence |
http://www.ncbi.nlm.nih.gov/nuccore/NC_000964.3?from=2857736&to=2858622&strand=true&report=graph&content=5 |
http://www.ncbi.nlm.nih.gov/gene/937499 |
MinJ sequence |
http://www.ncbi.nlm.nih.gov/nuccore/NC_000964.3?from=3620287&to=3621598&strand=true&report=graph&content=5 |
http://www.ncbi.nlm.nih.gov/gene/936668 |
van Baarle, S., & Bramkamp, M. (2010). The MinCDJ system in Bacillus subtilis prevents minicell formation by promoting divisome disassembly. PloS one, 5(3), e9850. doi: 10.1371/journal.pone.0009850. |
Bramkamp, M. & van Baarle, S., 2009. Division site selection in rod-shaped bacteria. Current opinion in microbiology, 12(6), 683-8. Available at: http://www.ncbi.nlm.nih.gov/pubmed/19884039. |