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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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Localization of PLP to satellites requires Cnn CM2. Embryos were stained for the indicated proteins and imaged by confocal microscopy (A) or SIM (B). PLP satellites (orange arrows) are present in all genotypes but cnnB4 mutants, which resemble mitotic centrosomes. The PLP centriole pool is present in all genotypes (blue arrows). plp− and cnnB4 mutants do not properly assemble PCM around the centriole (brackets). Arrowheads show a cytoplasmic particle or rare PLP satellite in cnnB4 mutant. Bars: (A) 2.5 µm; (B) 1 µm.
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fig9: Localization of PLP to satellites requires Cnn CM2. Embryos were stained for the indicated proteins and imaged by confocal microscopy (A) or SIM (B). PLP satellites (orange arrows) are present in all genotypes but cnnB4 mutants, which resemble mitotic centrosomes. The PLP centriole pool is present in all genotypes (blue arrows). plp− and cnnB4 mutants do not properly assemble PCM around the centriole (brackets). Arrowheads show a cytoplasmic particle or rare PLP satellite in cnnB4 mutant. Bars: (A) 2.5 µm; (B) 1 µm.

Mentions: Despite producing normal levels of Cnn protein, prior detailed analysis of cnnB4 embryos indicates pronounced similarities in the PCM dispersion and NUF phenotypes we observe in plp− mutants (Kao and Megraw, 2009). Consistent with these studies, all interphase cnnB4 embryos display highly disordered Cnn and γTub (Figs. 9 A and S5 B; n = 34). PLP localization was not previously examined in cnnB4 mutants. Thus, to assay the significance of the Cnn CM2 interaction with PLP-F2, we examined PLP distribution in control and cnnB4 embryos. Significantly, localization of PLP to the satellites is eliminated in interphase cnnB4 embryos, whereas PLP at centrioles is unperturbed (Fig. 9 A; n = 34). The effect of Cnn on PLP satellite formation is specific, as disruption of other PCM factors, such as TACC and MSPS, previously localized to flare-like particles (Lee et al., 2001), did not alter PLP satellite formation (Fig. 9 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)

Localization of PLP to satellites requires Cnn CM2. Embryos were stained for the indicated proteins and imaged by confocal microscopy (A) or SIM (B). PLP satellites (orange arrows) are present in all genotypes but cnnB4 mutants, which resemble mitotic centrosomes. The PLP centriole pool is present in all genotypes (blue arrows). plp− and cnnB4 mutants do not properly assemble PCM around the centriole (brackets). Arrowheads show a cytoplasmic particle or rare PLP satellite in cnnB4 mutant. Bars: (A) 2.5 µm; (B) 1 µm.
© Copyright Policy - openaccess
Related In: Results  -  Collection

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

fig9: Localization of PLP to satellites requires Cnn CM2. Embryos were stained for the indicated proteins and imaged by confocal microscopy (A) or SIM (B). PLP satellites (orange arrows) are present in all genotypes but cnnB4 mutants, which resemble mitotic centrosomes. The PLP centriole pool is present in all genotypes (blue arrows). plp− and cnnB4 mutants do not properly assemble PCM around the centriole (brackets). Arrowheads show a cytoplasmic particle or rare PLP satellite in cnnB4 mutant. Bars: (A) 2.5 µm; (B) 1 µm.
Mentions: Despite producing normal levels of Cnn protein, prior detailed analysis of cnnB4 embryos indicates pronounced similarities in the PCM dispersion and NUF phenotypes we observe in plp− mutants (Kao and Megraw, 2009). Consistent with these studies, all interphase cnnB4 embryos display highly disordered Cnn and γTub (Figs. 9 A and S5 B; n = 34). PLP localization was not previously examined in cnnB4 mutants. Thus, to assay the significance of the Cnn CM2 interaction with PLP-F2, we examined PLP distribution in control and cnnB4 embryos. Significantly, localization of PLP to the satellites is eliminated in interphase cnnB4 embryos, whereas PLP at centrioles is unperturbed (Fig. 9 A; n = 34). The effect of Cnn on PLP satellite formation is specific, as disruption of other PCM factors, such as TACC and MSPS, previously localized to flare-like particles (Lee et al., 2001), did not alter PLP satellite formation (Fig. 9 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