Fiche publication
Date publication
juillet 2015
Journal
Proceedings of the National Academy of Sciences of the United States of America
Auteurs
Membres identifiés du Cancéropôle Est :
Mr ALIOUA Abdelmalek
Tous les auteurs :
Batzenschlager M, Lermontova I, Schubert V, Fuchs J, Berr A, Koini MA, Houlné G, Herzog E, Rutten T, Alioua A, Fransz P, Schmit AC, Chabouté ME
Lien Pubmed
Résumé
Centromeres play a pivotal role in maintaining genome integrity by facilitating the recruitment of kinetochore and sister-chromatid cohesion proteins, both required for correct chromosome segregation. Centromeres are epigenetically specified by the presence of the histone H3 variant (CENH3). In this study, we investigate the role of the highly conserved γ-tubulin complex protein 3-interacting proteins (GIPs) in Arabidopsis centromere regulation. We show that GIPs form a complex with CENH3 in cycling cells. GIP depletion in the gip1gip2 knockdown mutant leads to a decreased CENH3 level at centromeres, despite a higher level of Mis18BP1/KNL2 present at both centromeric and ectopic sites. We thus postulate that GIPs are required to ensure CENH3 deposition and/or maintenance at centromeres. In addition, the recruitment at the centromere of other proteins such as the CENP-C kinetochore component and the cohesin subunit SMC3 is impaired in gip1gip2. These defects in centromere architecture result in aneuploidy due to severely altered centromeric cohesion. Altogether, we ascribe a central function to GIPs for the proper recruitment and/or stabilization of centromeric proteins essential in the specification of the centromere identity, as well as for centromeric cohesion in somatic cells.
Mots clés
Arabidopsis, MZT1, centromere assembly, centromeric cohesion, ploidy stability
Référence
Proc Natl Acad Sci U S A. 2015 07 14;112(28):8656-60
