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Accueil du site > Animations Scientifiques > Séminaires 2011 > Christian Jaulin — Regulation of sister chromatid cohesion by histone modifications at centromeres

Christian Jaulin — Regulation of sister chromatid cohesion by histone modifications at centromeres

Speaker :

Christian Jaulin, Institut de Génétique et Développement de Rennes, CNRS, Faculté de Médecine

When :

Wednesday 14 september at 11am

Where :

C023 (RDC LR6 côté Centre Blaise Pascal)

Title :

Regulation of sister chromatid cohesion by histone modifications at centromeres

Abstract :

The maintenance of sister chromatid cohesion at centromeres until anaphase onset requires the recruitment of protection factors, such as shugoshin and the haspin kinase. We previously showed that the acetylation of H3 lysine 4 (H3K4) at centromeres prevents shugoshin recruitment, thereby hampering the haspin-mediated phosphorylation of histone H3 threonine 3 (H3T3) and resulting in a loss of sister chromatid cohesion (1). We report here that phosphorylation of the CENP-A serine 7 (CENP-AS7) residue by the Aurora A kinase is also required for correct H3T3 phosphorylation and the maintenance of sister chromatid cohesion. We detected Aurora A at centromeres and found that the distribution of this kinase was dependent on the presence of Bub1, which has been implicated in the targeting of shugoshin to centromeres through Bub-1 mediated histone H2 threonine 120 phosphorylation. However, Aurora A-mediated CENP-AS7 phosphorylation was not required for shugoshin recruitment and, conversely, shugoshin depletion did not prevent the targeting of Aurora A to the centromere and CENP-AS7 phosphorylation. We also found that H3K4 acetylation at centromeres prevented Bub1 from becoming targeted to these sites. These results suggest that the maintenance of sister chromatid cohesion at centromeres is controlled by a complex “histone code”-mediated signaling pathway.

(1) Eot-Houllier, G., Fulcrand, G., Watanabe, Y., Magnaghi-Jaulin, L., and Jaulin, C. (2008). Histone deacetylase 3 is required for centromeric H3K4 deacetylation and sister chromatid cohesion. Genes Dev 22, 2639-2644.

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