SUMOylation promotes de novo targeting of HP1α to pericentric heterochromatin.

Christèle Maison (1) , Delphine Bailly (1) , Danièle Roche (1) , Rocio Montes de Oca (1) , Aline V Probst (1) , Isabelle Vassias (2) , Florent Dingli (3) , Bérengère Lombard (4) , Damarys Loew (3) , Jean-Pierre Quivy (1) , Geneviève Almouzni (1)

1 DNPG - Dynamique nucléaire et plasticité du génome
2 LNRS - Laboratoire de Neurobiologie des Réseaux Sensorimoteurs
3 Laboratoire de Spectrométrie de Masse Protéomique
4 Institut Curie [Paris]

HP1 enrichment at pericentric heterochromatin is considered important for centromere function. Although HP1 binding to H3K9me3 can explain its accumulation at pericentric heterochromatin, how it is initially targeted there remains unclear. Here, in mouse cells, we reveal the presence of long nuclear noncoding transcripts corresponding to major satellite repeats at the periphery of pericentric heterochromatin. Furthermore, we find that major transcripts in the forward orientation specifically associate with SUMO-modified HP1 proteins. We identified this modification as SUMO-1 and mapped it in the hinge domain of HP1α. Notably, the hinge domain and its SUMOylation proved critical to promote the initial targeting of HP1α to pericentric domains using de novo localization assays, whereas they are dispensable for maintenance of HP1 domains. We propose that SUMO-HP1, through a specific association with major forward transcript, is guided at the pericentric heterochromatin domain to seed further HP1 localization.

Domaines: Biologie cellulaire

Christèle Maison, Delphine Bailly, Danièle Roche, Rocio Montes de Oca, Aline V Probst, et al.. SUMOylation promotes de novo targeting of HP1α to pericentric heterochromatin.. Nature Genetics, 2011, 43 (3), pp.220-7. ⟨10.1038/ng.765⟩. ⟨hal-00685744⟩