TY - JOUR

T1 - The role of Xist-mediated Polycomb recruitment in the initiation of X-chromosome inactivation

AU - Bousard, Aurélie

AU - Raposo, Ana Cláudia

AU - Żylicz, Jan Jakub

AU - Picard, Christel

AU - Pires, Vanessa Borges

AU - Qi, Yanyan

AU - Gil, Cláudia

AU - Syx, Laurène

AU - Chang, Howard Y.

AU - Heard, Edith

AU - da Rocha, Simão Teixeira

N1 - Funding Information: We thank Elphège Nora, Rafael Galupa, Martin Escamilla-Del-Arenal, and Sérgio de Almeida for critical reading of the manuscript. We are also grateful to members of the Heard Lab (Curie Institute), members of the Carmo-Fonseca's Lab (iMM JLA), in particular to Kenny Rebelo, and also to Pierre Gestraud and Nicolas Servant (U900, Curie Institute) and Aurélie Teissandier (U934/UMR3215, Curie Institute) for their help and critical input to this project. We also want to thank the Bioimaging facility, in particular José Rino, at iMM JLA for their technical support with fluorescent light microscopy and imaging analysis. This work was supported by Fundação para a Ciência e Tecnologia (FCT), project grants PTDC/BEX-BCM/2612/2014 (A.C.R. and S.T.d.R), PTDC/BIA-MOL/29320/2017 IC&DT (C.G. and S.T.d.R), and IF/00242/2014 (V.P. and S.T.d.R), by an ERC Advanced Investigator award ERC-ADG-2014 671027 attributed to E.H. and Sir Henry Wellcome Postdoctoral Fellowship (J.J.Z.), by the Scleroderma Research Foundation (Y.Q., H.Y.C) and by US National Institutes of Health NIH P50-HG007735 (H.Y.C.). H.Y.C. is an Investigator of the Howard Hughes Medical Institute. Publication costs were supported by UID/BIM/50005/2019, project funded by Fundação para a Ciência e a Tecnologia (FCT)/ Ministério da Ciência, Tecnologia e Ensino Superior (MCTES) through Fundos do Orçamento de Estado. Publisher Copyright: © 2019 The Authors. Published under the terms of the CC BY 4.0 license

PY - 2019/10/4

Y1 - 2019/10/4

N2 - Xist RNA has been established as the master regulator of X-chromosome inactivation (XCI) in female eutherian mammals, but its mechanism of action remains unclear. By creating novel Xist-inducible mutants at the endogenous locus in male mouse embryonic stem (ES) cells, we dissect the role of the conserved A-B-C-F repeats in the initiation of XCI. We find that transcriptional silencing can be largely uncoupled from Polycomb repressive complex 1 and complex 2 (PRC1/2) recruitment, which requires B and C repeats. Xist ΔB+C RNA specifically loses interaction with PCGF3/5 subunits of PRC1, while binding of other Xist partners is largely unaffected. However, a slight relaxation of transcriptional silencing in Xist ΔB+C indicates a role for PRC1/2 proteins in early stabilization of gene repression. Distinct modules within the Xist RNA are therefore involved in the convergence of independent chromatin modification and gene repression pathways. In this context, Polycomb recruitment seems to be of moderate relevance in the initiation of silencing.

AB - Xist RNA has been established as the master regulator of X-chromosome inactivation (XCI) in female eutherian mammals, but its mechanism of action remains unclear. By creating novel Xist-inducible mutants at the endogenous locus in male mouse embryonic stem (ES) cells, we dissect the role of the conserved A-B-C-F repeats in the initiation of XCI. We find that transcriptional silencing can be largely uncoupled from Polycomb repressive complex 1 and complex 2 (PRC1/2) recruitment, which requires B and C repeats. Xist ΔB+C RNA specifically loses interaction with PCGF3/5 subunits of PRC1, while binding of other Xist partners is largely unaffected. However, a slight relaxation of transcriptional silencing in Xist ΔB+C indicates a role for PRC1/2 proteins in early stabilization of gene repression. Distinct modules within the Xist RNA are therefore involved in the convergence of independent chromatin modification and gene repression pathways. In this context, Polycomb recruitment seems to be of moderate relevance in the initiation of silencing.

KW - chromatin

KW - PRC1

KW - PRC2

KW - X-chromosome inactivation

KW - Xist

UR - http://www.scopus.com/inward/record.url?scp=85071299357&partnerID=8YFLogxK

U2 - 10.15252/embr.201948019

DO - 10.15252/embr.201948019

M3 - Journal article

C2 - 31456285

AN - SCOPUS:85071299357

VL - 20

JO - E M B O Reports

JF - E M B O Reports

SN - 1469-221X

IS - 10

M1 - e48019

ER -