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Interphase centrosome organization by the PLP-Cnn scaffold is required for centrosome function.

Lerit DA, Jordan HA, Poulton JS, Fagerstrom CJ, Galletta BJ, Peifer M, Rusan NM - J. Cell Biol. (2015)

Bottom Line: Pericentriolar material (PCM) mediates the microtubule (MT) nucleation and anchoring activity of centrosomes.A scaffold organized by Centrosomin (Cnn) serves to ensure proper PCM architecture and functional changes in centrosome activity with each cell cycle.Focusing on the mitotic-to-interphase transition in Drosophila melanogaster embryos, we show that the elaboration of the interphase Cnn scaffold defines a major structural rearrangement of the centrosome.

View Article: PubMed Central - HTML - PubMed

Affiliation: Cell Biology and Physiology Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892.

ABSTRACT
Pericentriolar material (PCM) mediates the microtubule (MT) nucleation and anchoring activity of centrosomes. A scaffold organized by Centrosomin (Cnn) serves to ensure proper PCM architecture and functional changes in centrosome activity with each cell cycle. Here, we investigate the mechanisms that spatially restrict and temporally coordinate centrosome scaffold formation. Focusing on the mitotic-to-interphase transition in Drosophila melanogaster embryos, we show that the elaboration of the interphase Cnn scaffold defines a major structural rearrangement of the centrosome. We identify an unprecedented role for Pericentrin-like protein (PLP), which localizes to the tips of extended Cnn flares, to maintain robust interphase centrosome activity and promote the formation of interphase MT asters required for normal nuclear spacing, centrosome segregation, and compartmentalization of the syncytial embryo. Our data reveal that Cnn and PLP directly interact at two defined sites to coordinate the cell cycle-dependent rearrangement and scaffolding activity of the centrosome to permit normal centrosome organization, cell division, and embryonic viability.

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PLPFL localizes to dynamic satellite structures. (A and B) Embryos were stained for the indicated proteins. Arrows show PLP at centrioles (blue) and satellites (brown). The boxed sections are enlarged below. (C) Live PLPFL shows interphase PLP satellites (arrowheads) in NC 12 and 13. Time is given in minutes:seconds. (D) Anterograde (green) and retrograde (blue) satellite run relative to centriole (asterisk). Time is given in seconds. (D′) Corresponding kymograph and plot of distance over time (D″). (E) Average velocity of directed runs; n.s., not significant; n = 27 runs. (F) Frequency of satellites with directed (≥0.5 µm) runs; n = 58 centrosomes. Bars: (A and B, top) 5 µm; (A and B, bottom) 1 µm; (C) 5 µm; (D) 2 µm.
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fig3: PLPFL localizes to dynamic satellite structures. (A and B) Embryos were stained for the indicated proteins. Arrows show PLP at centrioles (blue) and satellites (brown). The boxed sections are enlarged below. (C) Live PLPFL shows interphase PLP satellites (arrowheads) in NC 12 and 13. Time is given in minutes:seconds. (D) Anterograde (green) and retrograde (blue) satellite run relative to centriole (asterisk). Time is given in seconds. (D′) Corresponding kymograph and plot of distance over time (D″). (E) Average velocity of directed runs; n.s., not significant; n = 27 runs. (F) Frequency of satellites with directed (≥0.5 µm) runs; n = 58 centrosomes. Bars: (A and B, top) 5 µm; (A and B, bottom) 1 µm; (C) 5 µm; (D) 2 µm.

Mentions: To investigate the function of PLP satellites in detail, we examined live embryos expressing full-length PLP-GFP (PLPFL), which mirrors endogenous PLP distribution (Fig. 3, A and B) and fully rescues plp− viability (Galletta et al., 2014). Live imaging shows that PLPFL remains closely apposed to centrioles throughout the cell cycle, but expands into the flare zone as PLP satellites in interphase (30/31 embryos; Fig. 3 C and Video 3). Satellites diminish upon nuclear envelope breakdown (Fig. 3 C, 3:30), are absent in mitosis (Fig. 3 C, 7:00), reemerge in interphase during centrosome separation (Fig. 3 C, 10:30), and become prominent once centrosomes fully separate (Fig. 3 C, 19:00). Therefore, PLP satellite assembly and disassembly are entrained with the cell cycle where satellite-permissive conditions are present during interphase. Moreover, the timing of PLP satellite addition and removal bears a striking resemblance to that of Cnn flares (Fig. 1 A).


Interphase centrosome organization by the PLP-Cnn scaffold is required for centrosome function.

Lerit DA, Jordan HA, Poulton JS, Fagerstrom CJ, Galletta BJ, Peifer M, Rusan NM - J. Cell Biol. (2015)

PLPFL localizes to dynamic satellite structures. (A and B) Embryos were stained for the indicated proteins. Arrows show PLP at centrioles (blue) and satellites (brown). The boxed sections are enlarged below. (C) Live PLPFL shows interphase PLP satellites (arrowheads) in NC 12 and 13. Time is given in minutes:seconds. (D) Anterograde (green) and retrograde (blue) satellite run relative to centriole (asterisk). Time is given in seconds. (D′) Corresponding kymograph and plot of distance over time (D″). (E) Average velocity of directed runs; n.s., not significant; n = 27 runs. (F) Frequency of satellites with directed (≥0.5 µm) runs; n = 58 centrosomes. Bars: (A and B, top) 5 µm; (A and B, bottom) 1 µm; (C) 5 µm; (D) 2 µm.
© Copyright Policy - openaccess
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4494003&req=5

fig3: PLPFL localizes to dynamic satellite structures. (A and B) Embryos were stained for the indicated proteins. Arrows show PLP at centrioles (blue) and satellites (brown). The boxed sections are enlarged below. (C) Live PLPFL shows interphase PLP satellites (arrowheads) in NC 12 and 13. Time is given in minutes:seconds. (D) Anterograde (green) and retrograde (blue) satellite run relative to centriole (asterisk). Time is given in seconds. (D′) Corresponding kymograph and plot of distance over time (D″). (E) Average velocity of directed runs; n.s., not significant; n = 27 runs. (F) Frequency of satellites with directed (≥0.5 µm) runs; n = 58 centrosomes. Bars: (A and B, top) 5 µm; (A and B, bottom) 1 µm; (C) 5 µm; (D) 2 µm.
Mentions: To investigate the function of PLP satellites in detail, we examined live embryos expressing full-length PLP-GFP (PLPFL), which mirrors endogenous PLP distribution (Fig. 3, A and B) and fully rescues plp− viability (Galletta et al., 2014). Live imaging shows that PLPFL remains closely apposed to centrioles throughout the cell cycle, but expands into the flare zone as PLP satellites in interphase (30/31 embryos; Fig. 3 C and Video 3). Satellites diminish upon nuclear envelope breakdown (Fig. 3 C, 3:30), are absent in mitosis (Fig. 3 C, 7:00), reemerge in interphase during centrosome separation (Fig. 3 C, 10:30), and become prominent once centrosomes fully separate (Fig. 3 C, 19:00). Therefore, PLP satellite assembly and disassembly are entrained with the cell cycle where satellite-permissive conditions are present during interphase. Moreover, the timing of PLP satellite addition and removal bears a striking resemblance to that of Cnn flares (Fig. 1 A).

Bottom Line: Pericentriolar material (PCM) mediates the microtubule (MT) nucleation and anchoring activity of centrosomes.A scaffold organized by Centrosomin (Cnn) serves to ensure proper PCM architecture and functional changes in centrosome activity with each cell cycle.Focusing on the mitotic-to-interphase transition in Drosophila melanogaster embryos, we show that the elaboration of the interphase Cnn scaffold defines a major structural rearrangement of the centrosome.

View Article: PubMed Central - HTML - PubMed

Affiliation: Cell Biology and Physiology Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892.

ABSTRACT
Pericentriolar material (PCM) mediates the microtubule (MT) nucleation and anchoring activity of centrosomes. A scaffold organized by Centrosomin (Cnn) serves to ensure proper PCM architecture and functional changes in centrosome activity with each cell cycle. Here, we investigate the mechanisms that spatially restrict and temporally coordinate centrosome scaffold formation. Focusing on the mitotic-to-interphase transition in Drosophila melanogaster embryos, we show that the elaboration of the interphase Cnn scaffold defines a major structural rearrangement of the centrosome. We identify an unprecedented role for Pericentrin-like protein (PLP), which localizes to the tips of extended Cnn flares, to maintain robust interphase centrosome activity and promote the formation of interphase MT asters required for normal nuclear spacing, centrosome segregation, and compartmentalization of the syncytial embryo. Our data reveal that Cnn and PLP directly interact at two defined sites to coordinate the cell cycle-dependent rearrangement and scaffolding activity of the centrosome to permit normal centrosome organization, cell division, and embryonic viability.

Show MeSH
Related in: MedlinePlus