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A stable microtubule array drives fission yeast polarity reestablishment upon quiescence exit.

Laporte D, Courtout F, Pinson B, Dompierre J, Salin B, Brocard L, Sagot I - J. Cell Biol. (2015)

Bottom Line: Astonishingly, MTs are also stabilized and rearranged into a novel antiparallel bundle associated with the spindle pole body, named Q-MT bundle.Finally and importantly, we reveal that Q-MT bundle elongation is involved in polarity reestablishment upon quiescence exit and thereby the efficient return to the proliferative state.Our work demonstrates that quiescent S. pombe cells assemble specific cytoskeleton structures that improve the swiftness of the transition back to proliferation.

View Article: PubMed Central - HTML - PubMed

Affiliation: Université de Bordeaux, Institut de Biochimie et Génétique Cellulaires, 33000 Bordeaux, France Centre National de la Recherche Scientifique, UMR5095 Bordeaux, 33077 Bordeaux, France.

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The Q-MT bundle is composed of stable MTs. (A) Q-MT bundles do not display detectable length variation. Variation of MT bundle length as a function of time in interphase and quiescent cells. Representative time-lapse movies are shown. Red and blue arrows point, respectively, at shrinking and growing MTs. (B) Q-MT bundles are insensitive to treatments that destabilize dynamic MTs. The graph displays MT bundle length measured in interphase and in quiescent cells (4 d) incubated 30 min with the indicated drugs. Representative cells are shown. (C) FRAP of GFP-Atb2 within a Q-MT bundle measured in quiescent cells (4 d). Error bars are SEM. Time is in seconds. The red box indicates the photobleached area. In all panels, cells are WT cells expressing GFP-Atb2, Sfi1-CFP, and Cut11-RFP. In A and C, only the GFP channel is shown, and in B GFP-Atb2 is in green and Cut11-RFP is in red. Bars, 2 µm.
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fig2: The Q-MT bundle is composed of stable MTs. (A) Q-MT bundles do not display detectable length variation. Variation of MT bundle length as a function of time in interphase and quiescent cells. Representative time-lapse movies are shown. Red and blue arrows point, respectively, at shrinking and growing MTs. (B) Q-MT bundles are insensitive to treatments that destabilize dynamic MTs. The graph displays MT bundle length measured in interphase and in quiescent cells (4 d) incubated 30 min with the indicated drugs. Representative cells are shown. (C) FRAP of GFP-Atb2 within a Q-MT bundle measured in quiescent cells (4 d). Error bars are SEM. Time is in seconds. The red box indicates the photobleached area. In all panels, cells are WT cells expressing GFP-Atb2, Sfi1-CFP, and Cut11-RFP. In A and C, only the GFP channel is shown, and in B GFP-Atb2 is in green and Cut11-RFP is in red. Bars, 2 µm.

Mentions: In interphase cells, cytoplasmic MTs are known to be extremely dynamic as they rapidly alternate periods of growth and shrinkage (Fig. 2 A; Drummond and Cross, 2000). They are therefore very sensitive to drugs that inhibit MT polymerization and cause dynamic MT disassembly, such as methyl benzimidazol-2-yl-carbamate (MBC) or thiabendazole (TBZ; Fig. 2 B; Sawin and Nurse, 1998; Sawin and Snaith, 2004). In contrast, we showed that in quiescent cells, the Q-MT bundle had a constant length (Fig. 2 A) and resisted against massive amounts of drugs (Fig. 2 B) or a cold treatment known to cause the disassembly of dynamic MTs (Fig. S2, A and B). Importantly, no fluorescence was recovered after GFP-Atb2 photobleaching, demonstrating that within the Q-MT bundle, not only MTs were stable but also there was no MT sliding (Fig. 2 C). Of note, like cells entering quiescence upon carbon source exhaustion, upon nitrogen starvation, cells also stabilized a unique MT bundle (Fig. S2 C).


A stable microtubule array drives fission yeast polarity reestablishment upon quiescence exit.

Laporte D, Courtout F, Pinson B, Dompierre J, Salin B, Brocard L, Sagot I - J. Cell Biol. (2015)

The Q-MT bundle is composed of stable MTs. (A) Q-MT bundles do not display detectable length variation. Variation of MT bundle length as a function of time in interphase and quiescent cells. Representative time-lapse movies are shown. Red and blue arrows point, respectively, at shrinking and growing MTs. (B) Q-MT bundles are insensitive to treatments that destabilize dynamic MTs. The graph displays MT bundle length measured in interphase and in quiescent cells (4 d) incubated 30 min with the indicated drugs. Representative cells are shown. (C) FRAP of GFP-Atb2 within a Q-MT bundle measured in quiescent cells (4 d). Error bars are SEM. Time is in seconds. The red box indicates the photobleached area. In all panels, cells are WT cells expressing GFP-Atb2, Sfi1-CFP, and Cut11-RFP. In A and C, only the GFP channel is shown, and in B GFP-Atb2 is in green and Cut11-RFP is in red. Bars, 2 µm.
© Copyright Policy - openaccess
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4494004&req=5

fig2: The Q-MT bundle is composed of stable MTs. (A) Q-MT bundles do not display detectable length variation. Variation of MT bundle length as a function of time in interphase and quiescent cells. Representative time-lapse movies are shown. Red and blue arrows point, respectively, at shrinking and growing MTs. (B) Q-MT bundles are insensitive to treatments that destabilize dynamic MTs. The graph displays MT bundle length measured in interphase and in quiescent cells (4 d) incubated 30 min with the indicated drugs. Representative cells are shown. (C) FRAP of GFP-Atb2 within a Q-MT bundle measured in quiescent cells (4 d). Error bars are SEM. Time is in seconds. The red box indicates the photobleached area. In all panels, cells are WT cells expressing GFP-Atb2, Sfi1-CFP, and Cut11-RFP. In A and C, only the GFP channel is shown, and in B GFP-Atb2 is in green and Cut11-RFP is in red. Bars, 2 µm.
Mentions: In interphase cells, cytoplasmic MTs are known to be extremely dynamic as they rapidly alternate periods of growth and shrinkage (Fig. 2 A; Drummond and Cross, 2000). They are therefore very sensitive to drugs that inhibit MT polymerization and cause dynamic MT disassembly, such as methyl benzimidazol-2-yl-carbamate (MBC) or thiabendazole (TBZ; Fig. 2 B; Sawin and Nurse, 1998; Sawin and Snaith, 2004). In contrast, we showed that in quiescent cells, the Q-MT bundle had a constant length (Fig. 2 A) and resisted against massive amounts of drugs (Fig. 2 B) or a cold treatment known to cause the disassembly of dynamic MTs (Fig. S2, A and B). Importantly, no fluorescence was recovered after GFP-Atb2 photobleaching, demonstrating that within the Q-MT bundle, not only MTs were stable but also there was no MT sliding (Fig. 2 C). Of note, like cells entering quiescence upon carbon source exhaustion, upon nitrogen starvation, cells also stabilized a unique MT bundle (Fig. S2 C).

Bottom Line: Astonishingly, MTs are also stabilized and rearranged into a novel antiparallel bundle associated with the spindle pole body, named Q-MT bundle.Finally and importantly, we reveal that Q-MT bundle elongation is involved in polarity reestablishment upon quiescence exit and thereby the efficient return to the proliferative state.Our work demonstrates that quiescent S. pombe cells assemble specific cytoskeleton structures that improve the swiftness of the transition back to proliferation.

View Article: PubMed Central - HTML - PubMed

Affiliation: Université de Bordeaux, Institut de Biochimie et Génétique Cellulaires, 33000 Bordeaux, France Centre National de la Recherche Scientifique, UMR5095 Bordeaux, 33077 Bordeaux, France.

Show MeSH
Related in: MedlinePlus