Limits...
Aurora B prevents chromosome arm separation defects by promoting telomere dispersion and disjunction.

Reyes C, Serrurier C, Gauthier T, Gachet Y, Tournier S - J. Cell Biol. (2015)

Bottom Line: Dispersion is promoted by the dissociation of Swi6/HP1 and cohesin Rad21 from telomeres, whereas disjunction occurs at anaphase after the phosphorylation of condensin subunit Cnd2.Strikingly, we demonstrate that deletion of Ccq1, a telomeric shelterin component, rescued cell death after Aurora inhibition by promoting the loading of condensin on chromosome arms.Our findings reveal an essential role for telomeres in chromosome arm segregation.

View Article: PubMed Central - HTML - PubMed

Affiliation: Laboratoire de biologie cellulaire et moléculaire du contrôle de la prolifération, Université de Toulouse, F-31062 Toulouse, France Centre National de la Recherche Scientifique, LBCMCP-UMR5088, F-31062 Toulouse, France.

Show MeSH

Related in: MedlinePlus

Aurora B kinase colocalizes with telomeres in metaphase and controls sister chromatid telomere dispersion and disjunction. (A) Movie of a cell expressing Taz1-rfp (telomeres, red), Ark1-gfp (Aurora, green), and Cdc11-cfp (SPB, blue) during mitotic progression. In metaphase (first four panels), Aurora transiently colocalizes to telomeres (arrows), whereas in anaphase (last two panels), it is absent from telomeres and present at the spindle midzone. (B) Schematic description of the procedure used to specifically inhibit Aurora kinase in early mitosis. (C) cdc25-22 ark1-as3 (red, n = 98, and black, n = 62) or cdc25-22 (gray, n = 60) cells were synchronized in G2 (36°C) and released in metaphase (25°C) before adding 10 µM Napp1 (Aurora inhibition). Synchronized mitotic cells were filmed through mitosis in the presence (Aurora inhibition, red) or absence (No inhibition or control, gray and black) of 10 µM Napp1 and the number of Taz1 dots was counted according to spindle length. The data shown are from a single representative experiment out of three repeats. (D) Example of the phenotypes seen in cdc25-22 ark1-as3 cells treated or not with 10 µM Napp1. Note that after Aurora inhibition, in a proportion of cells, centromeres are separated (Mis6 signal, left) but telomeres (Taz1 signal, left, or Pot1 signal, right) remain as clusters.
© Copyright Policy - openaccess
Related In: Results  -  Collection

License 1 - License 2
getmorefigures.php?uid=PMC4362453&req=5

fig2: Aurora B kinase colocalizes with telomeres in metaphase and controls sister chromatid telomere dispersion and disjunction. (A) Movie of a cell expressing Taz1-rfp (telomeres, red), Ark1-gfp (Aurora, green), and Cdc11-cfp (SPB, blue) during mitotic progression. In metaphase (first four panels), Aurora transiently colocalizes to telomeres (arrows), whereas in anaphase (last two panels), it is absent from telomeres and present at the spindle midzone. (B) Schematic description of the procedure used to specifically inhibit Aurora kinase in early mitosis. (C) cdc25-22 ark1-as3 (red, n = 98, and black, n = 62) or cdc25-22 (gray, n = 60) cells were synchronized in G2 (36°C) and released in metaphase (25°C) before adding 10 µM Napp1 (Aurora inhibition). Synchronized mitotic cells were filmed through mitosis in the presence (Aurora inhibition, red) or absence (No inhibition or control, gray and black) of 10 µM Napp1 and the number of Taz1 dots was counted according to spindle length. The data shown are from a single representative experiment out of three repeats. (D) Example of the phenotypes seen in cdc25-22 ark1-as3 cells treated or not with 10 µM Napp1. Note that after Aurora inhibition, in a proportion of cells, centromeres are separated (Mis6 signal, left) but telomeres (Taz1 signal, left, or Pot1 signal, right) remain as clusters.

Mentions: We performed live imaging of cells simultaneously expressing markers for the SPBs (Cdc11-cfp), telomeres (Taz1-rfp), and Aurora B (Ark1-gfp). In addition to its well-known localization at the kinetochore and the spindle midzone (Adams et al., 2001; Giet and Glover, 2001), Aurora B also colocalized, transiently, to the telomeres in metaphase (Fig. 2 A, 0–3 min, arrows). Localization to the telomeres was not observed after anaphase onset (Fig. 2 A, 4 and 5 min).


Aurora B prevents chromosome arm separation defects by promoting telomere dispersion and disjunction.

Reyes C, Serrurier C, Gauthier T, Gachet Y, Tournier S - J. Cell Biol. (2015)

Aurora B kinase colocalizes with telomeres in metaphase and controls sister chromatid telomere dispersion and disjunction. (A) Movie of a cell expressing Taz1-rfp (telomeres, red), Ark1-gfp (Aurora, green), and Cdc11-cfp (SPB, blue) during mitotic progression. In metaphase (first four panels), Aurora transiently colocalizes to telomeres (arrows), whereas in anaphase (last two panels), it is absent from telomeres and present at the spindle midzone. (B) Schematic description of the procedure used to specifically inhibit Aurora kinase in early mitosis. (C) cdc25-22 ark1-as3 (red, n = 98, and black, n = 62) or cdc25-22 (gray, n = 60) cells were synchronized in G2 (36°C) and released in metaphase (25°C) before adding 10 µM Napp1 (Aurora inhibition). Synchronized mitotic cells were filmed through mitosis in the presence (Aurora inhibition, red) or absence (No inhibition or control, gray and black) of 10 µM Napp1 and the number of Taz1 dots was counted according to spindle length. The data shown are from a single representative experiment out of three repeats. (D) Example of the phenotypes seen in cdc25-22 ark1-as3 cells treated or not with 10 µM Napp1. Note that after Aurora inhibition, in a proportion of cells, centromeres are separated (Mis6 signal, left) but telomeres (Taz1 signal, left, or Pot1 signal, right) remain as clusters.
© Copyright Policy - openaccess
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4362453&req=5

fig2: Aurora B kinase colocalizes with telomeres in metaphase and controls sister chromatid telomere dispersion and disjunction. (A) Movie of a cell expressing Taz1-rfp (telomeres, red), Ark1-gfp (Aurora, green), and Cdc11-cfp (SPB, blue) during mitotic progression. In metaphase (first four panels), Aurora transiently colocalizes to telomeres (arrows), whereas in anaphase (last two panels), it is absent from telomeres and present at the spindle midzone. (B) Schematic description of the procedure used to specifically inhibit Aurora kinase in early mitosis. (C) cdc25-22 ark1-as3 (red, n = 98, and black, n = 62) or cdc25-22 (gray, n = 60) cells were synchronized in G2 (36°C) and released in metaphase (25°C) before adding 10 µM Napp1 (Aurora inhibition). Synchronized mitotic cells were filmed through mitosis in the presence (Aurora inhibition, red) or absence (No inhibition or control, gray and black) of 10 µM Napp1 and the number of Taz1 dots was counted according to spindle length. The data shown are from a single representative experiment out of three repeats. (D) Example of the phenotypes seen in cdc25-22 ark1-as3 cells treated or not with 10 µM Napp1. Note that after Aurora inhibition, in a proportion of cells, centromeres are separated (Mis6 signal, left) but telomeres (Taz1 signal, left, or Pot1 signal, right) remain as clusters.
Mentions: We performed live imaging of cells simultaneously expressing markers for the SPBs (Cdc11-cfp), telomeres (Taz1-rfp), and Aurora B (Ark1-gfp). In addition to its well-known localization at the kinetochore and the spindle midzone (Adams et al., 2001; Giet and Glover, 2001), Aurora B also colocalized, transiently, to the telomeres in metaphase (Fig. 2 A, 0–3 min, arrows). Localization to the telomeres was not observed after anaphase onset (Fig. 2 A, 4 and 5 min).

Bottom Line: Dispersion is promoted by the dissociation of Swi6/HP1 and cohesin Rad21 from telomeres, whereas disjunction occurs at anaphase after the phosphorylation of condensin subunit Cnd2.Strikingly, we demonstrate that deletion of Ccq1, a telomeric shelterin component, rescued cell death after Aurora inhibition by promoting the loading of condensin on chromosome arms.Our findings reveal an essential role for telomeres in chromosome arm segregation.

View Article: PubMed Central - HTML - PubMed

Affiliation: Laboratoire de biologie cellulaire et moléculaire du contrôle de la prolifération, Université de Toulouse, F-31062 Toulouse, France Centre National de la Recherche Scientifique, LBCMCP-UMR5088, F-31062 Toulouse, France.

Show MeSH
Related in: MedlinePlus