Limits...
LocZ is a new cell division protein involved in proper septum placement in Streptococcus pneumoniae.

Holečková N, Doubravová L, Massidda O, Molle V, Buriánková K, Benada O, Kofroňová O, Ulrych A, Branny P - MBio (2014)

Bottom Line: Here, we characterized one of the StkP substrates, Spr0334, which we named LocZ.Consistently, LocZ supports proper Z-ring positioning at midcell.LocZ is conserved only among streptococci, lactococci, and enterococci, which lack homologues of the Min and nucleoid occlusion effectors, indicating that these bacteria adapted a unique mechanism to find their middle, reflecting their specific shape and symmetry.

View Article: PubMed Central - PubMed

Affiliation: Cell and Molecular Microbiology Division, Institute of Microbiology, v.v.i., Academy of Sciences of the Czech Republic, Prague, Czech Republic.

No MeSH data available.


Related in: MedlinePlus

Colocalization of LocZ and FtsZ, FtsA, or StkP. Double-labeled strains, expressing RFP-LocZ at the native locus from its native promoter and CFP-FtsZ, GFP-FtsA, or GFP-StkP from the constitutive or PczcD promoter, analyzed by fluorescence microscopy. Cells representing the six different stages of S. pneumoniae cell division are shown. The percentages of cells in each division stage, over 359, 389, and 354 cells counted, respectively, are indicated in the PH panel. All cells at each stage showed the same localization profile as that of the representative cell shown in the respective figure. (A) Sp242 (rfp-locZ, pBCSMH036) expresses CFP-FtsZ under the control of the constitutive promoter on the plasmid. (B) Sp256 (rfp-locZ bgaA::PczcD-gfp-ftsA) expresses GFP-FtsA under the control of the PczcD inducible promoter. (C) Sp248 (rfp-locZ bgaA::PczcD-gfp-stkP) expresses GFP-StkP under the control of the PczcD inducible promoter. Phase contrast (PH), GFP signal (GFP), CFP signal (CFP), RFP signal (RFP), and corresponding overlays are shown. Bar, 1 µm. Fluorescence intensity profiles of CFP-FtsZ (blue), GFP-FtsA (green), or GFP-StkP (green) versus RFP-LocZ (red) in arbitrary units (a.u.) along the cell length are shown on the right. Arrows indicate the cell analyzed in pictures containing multiple cells.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4281919&req=5

fig5: Colocalization of LocZ and FtsZ, FtsA, or StkP. Double-labeled strains, expressing RFP-LocZ at the native locus from its native promoter and CFP-FtsZ, GFP-FtsA, or GFP-StkP from the constitutive or PczcD promoter, analyzed by fluorescence microscopy. Cells representing the six different stages of S. pneumoniae cell division are shown. The percentages of cells in each division stage, over 359, 389, and 354 cells counted, respectively, are indicated in the PH panel. All cells at each stage showed the same localization profile as that of the representative cell shown in the respective figure. (A) Sp242 (rfp-locZ, pBCSMH036) expresses CFP-FtsZ under the control of the constitutive promoter on the plasmid. (B) Sp256 (rfp-locZ bgaA::PczcD-gfp-ftsA) expresses GFP-FtsA under the control of the PczcD inducible promoter. (C) Sp248 (rfp-locZ bgaA::PczcD-gfp-stkP) expresses GFP-StkP under the control of the PczcD inducible promoter. Phase contrast (PH), GFP signal (GFP), CFP signal (CFP), RFP signal (RFP), and corresponding overlays are shown. Bar, 1 µm. Fluorescence intensity profiles of CFP-FtsZ (blue), GFP-FtsA (green), or GFP-StkP (green) versus RFP-LocZ (red) in arbitrary units (a.u.) along the cell length are shown on the right. Arrows indicate the cell analyzed in pictures containing multiple cells.

Mentions: We analyzed then the cellular localization of the coexpressed fusion proteins at the six stages of pneumococcal cell division (Fig. 5; also see Fig. S4E in the supplemental material). As shown in Fig. 5, LocZ and FtsZ (Fig. 5A) or LocZ and FtsA (Fig. 5B) colocalize in cells at the predivisional stage 1, accounting for 7.8% (28/359) and 12% (47/389) of the cells, respectively. Soon after cell division starts, and the cells undergo the initial elongation (stage 2), LocZ splits into two bands that, as elongation proceeds, progressively move away from the center (stage 3). At these stages, CFP-FtsZ and GFP-FtsA are still detected as a ring at midcell, 19.5% (72/359) and 23.1% (83/389) and 20% (72/359) and 21.3% (83/389) of cells, respectively. This is best appreciated in the fluorescence intensity profiles of cells at stages 2 and 3, showing the RFP-LocZ signal separated into two peaks, while the CFP-FtsZ and GFP-FtsA signals are in a single midcell peak. As cell division progresses, an observable Z-ring constriction at the current division site coincides with new FtsZ and FtsA rings formed at the future division sites, occupied by LocZ (stage 4), 15.8% (57/359) and 17.7% (69/389) of cells, respectively. Consistently, the fluorescence intensity profiles corresponding to FtsZ and FtsA form a triple peak, with maxima at the center of the cells and two local maxima overlapping with RFP-LocZ peaks at the new equators. The relocalization of FtsZ and FtsA is even more evident at stage 5, where a complete overlap of the fluorescent signals at the equators of the daughter cells, i.e., the future division sites, 16.4% (59/359) and 12.1% (47/389) of the cells, respectively, is observed. Finally, in cells at stage 6, 20.3% (73/359) and 13.6% (53/389) of cells, which have completed cell division and represent newly born daughter cells, RFP-LocZ and CFP-FtsZ or GFP-FtsA, respectively, are again colocalized at midcell. These data indicate that LocZ arrives and leaves the midcell early, before FtsZ and FtsA, and that its position overlaps with the equators of the cell, which mark the sites for the next division.


LocZ is a new cell division protein involved in proper septum placement in Streptococcus pneumoniae.

Holečková N, Doubravová L, Massidda O, Molle V, Buriánková K, Benada O, Kofroňová O, Ulrych A, Branny P - MBio (2014)

Colocalization of LocZ and FtsZ, FtsA, or StkP. Double-labeled strains, expressing RFP-LocZ at the native locus from its native promoter and CFP-FtsZ, GFP-FtsA, or GFP-StkP from the constitutive or PczcD promoter, analyzed by fluorescence microscopy. Cells representing the six different stages of S. pneumoniae cell division are shown. The percentages of cells in each division stage, over 359, 389, and 354 cells counted, respectively, are indicated in the PH panel. All cells at each stage showed the same localization profile as that of the representative cell shown in the respective figure. (A) Sp242 (rfp-locZ, pBCSMH036) expresses CFP-FtsZ under the control of the constitutive promoter on the plasmid. (B) Sp256 (rfp-locZ bgaA::PczcD-gfp-ftsA) expresses GFP-FtsA under the control of the PczcD inducible promoter. (C) Sp248 (rfp-locZ bgaA::PczcD-gfp-stkP) expresses GFP-StkP under the control of the PczcD inducible promoter. Phase contrast (PH), GFP signal (GFP), CFP signal (CFP), RFP signal (RFP), and corresponding overlays are shown. Bar, 1 µm. Fluorescence intensity profiles of CFP-FtsZ (blue), GFP-FtsA (green), or GFP-StkP (green) versus RFP-LocZ (red) in arbitrary units (a.u.) along the cell length are shown on the right. Arrows indicate the cell analyzed in pictures containing multiple cells.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4281919&req=5

fig5: Colocalization of LocZ and FtsZ, FtsA, or StkP. Double-labeled strains, expressing RFP-LocZ at the native locus from its native promoter and CFP-FtsZ, GFP-FtsA, or GFP-StkP from the constitutive or PczcD promoter, analyzed by fluorescence microscopy. Cells representing the six different stages of S. pneumoniae cell division are shown. The percentages of cells in each division stage, over 359, 389, and 354 cells counted, respectively, are indicated in the PH panel. All cells at each stage showed the same localization profile as that of the representative cell shown in the respective figure. (A) Sp242 (rfp-locZ, pBCSMH036) expresses CFP-FtsZ under the control of the constitutive promoter on the plasmid. (B) Sp256 (rfp-locZ bgaA::PczcD-gfp-ftsA) expresses GFP-FtsA under the control of the PczcD inducible promoter. (C) Sp248 (rfp-locZ bgaA::PczcD-gfp-stkP) expresses GFP-StkP under the control of the PczcD inducible promoter. Phase contrast (PH), GFP signal (GFP), CFP signal (CFP), RFP signal (RFP), and corresponding overlays are shown. Bar, 1 µm. Fluorescence intensity profiles of CFP-FtsZ (blue), GFP-FtsA (green), or GFP-StkP (green) versus RFP-LocZ (red) in arbitrary units (a.u.) along the cell length are shown on the right. Arrows indicate the cell analyzed in pictures containing multiple cells.
Mentions: We analyzed then the cellular localization of the coexpressed fusion proteins at the six stages of pneumococcal cell division (Fig. 5; also see Fig. S4E in the supplemental material). As shown in Fig. 5, LocZ and FtsZ (Fig. 5A) or LocZ and FtsA (Fig. 5B) colocalize in cells at the predivisional stage 1, accounting for 7.8% (28/359) and 12% (47/389) of the cells, respectively. Soon after cell division starts, and the cells undergo the initial elongation (stage 2), LocZ splits into two bands that, as elongation proceeds, progressively move away from the center (stage 3). At these stages, CFP-FtsZ and GFP-FtsA are still detected as a ring at midcell, 19.5% (72/359) and 23.1% (83/389) and 20% (72/359) and 21.3% (83/389) of cells, respectively. This is best appreciated in the fluorescence intensity profiles of cells at stages 2 and 3, showing the RFP-LocZ signal separated into two peaks, while the CFP-FtsZ and GFP-FtsA signals are in a single midcell peak. As cell division progresses, an observable Z-ring constriction at the current division site coincides with new FtsZ and FtsA rings formed at the future division sites, occupied by LocZ (stage 4), 15.8% (57/359) and 17.7% (69/389) of cells, respectively. Consistently, the fluorescence intensity profiles corresponding to FtsZ and FtsA form a triple peak, with maxima at the center of the cells and two local maxima overlapping with RFP-LocZ peaks at the new equators. The relocalization of FtsZ and FtsA is even more evident at stage 5, where a complete overlap of the fluorescent signals at the equators of the daughter cells, i.e., the future division sites, 16.4% (59/359) and 12.1% (47/389) of the cells, respectively, is observed. Finally, in cells at stage 6, 20.3% (73/359) and 13.6% (53/389) of cells, which have completed cell division and represent newly born daughter cells, RFP-LocZ and CFP-FtsZ or GFP-FtsA, respectively, are again colocalized at midcell. These data indicate that LocZ arrives and leaves the midcell early, before FtsZ and FtsA, and that its position overlaps with the equators of the cell, which mark the sites for the next division.

Bottom Line: Here, we characterized one of the StkP substrates, Spr0334, which we named LocZ.Consistently, LocZ supports proper Z-ring positioning at midcell.LocZ is conserved only among streptococci, lactococci, and enterococci, which lack homologues of the Min and nucleoid occlusion effectors, indicating that these bacteria adapted a unique mechanism to find their middle, reflecting their specific shape and symmetry.

View Article: PubMed Central - PubMed

Affiliation: Cell and Molecular Microbiology Division, Institute of Microbiology, v.v.i., Academy of Sciences of the Czech Republic, Prague, Czech Republic.

No MeSH data available.


Related in: MedlinePlus