Skip to Content
Merck
  • EZH2 enables germinal centre formation through epigenetic silencing of CDKN1A and an Rb-E2F1 feedback loop.

EZH2 enables germinal centre formation through epigenetic silencing of CDKN1A and an Rb-E2F1 feedback loop.

Nature communications (2017-10-14)
Wendy Béguelin, Martín A Rivas, María T Calvo Fernández, Matt Teater, Alberto Purwada, David Redmond, Hao Shen, Matt F Challman, Olivier Elemento, Ankur Singh, Ari M Melnick
ABSTRACT

The EZH2 histone methyltransferase is required for B cells to form germinal centers (GC). Here we show that EZH2 mediates GC formation through repression of cyclin-dependent kinase inhibitor CDKN1A (p21Cip1). Deletion of Cdkn1a rescues the GC reaction in Ezh2 -/- mice. Using a 3D B cell follicular organoid system that mimics the GC reaction, we show that depletion of EZH2 suppresses G1 to S phase transition of GC B cells in a Cdkn1a-dependent manner. GC B cells of Cdkn1a -/- Ezh2 -/- mice have high levels of phospho-Rb, indicating that loss of Cdkn1a enables progression of cell cycle. Moreover, the transcription factor E2F1 induces EZH2 during the GC reaction. E2f1 -/- mice manifest impaired GC responses, which is rescued by restoring EZH2 expression, thus defining a positive feedback loop in which EZH2 controls GC B cell proliferation by suppressing CDKN1A, enabling cell cycle progression with a concomitant phosphorylation of Rb and release of E2F1.The histone methyltransferase EZH2 silences genes by generating H3K27me3 marks. Here the authors use a 3D GC organoid and show EZH2 mediates germinal centre (GC) formation through epigenetic silencing of CDKN1A and release of cell cycle checkpoints.

MATERIALS
Product Number
Brand
Product Description

Sigma-Aldrich
Monoclonal Anti-β-Actin antibody produced in mouse, clone AC-15, ascites fluid
Sigma-Aldrich
ChIPAb+ Trimethyl-Histone H3 (Lys27) - ChIP Validated Antibody and Primer Set, from rabbit, purified by using Protein A
Sigma-Aldrich
Anti-Histone H3 Antibody, CT, pan, serum, Upstate®
Sigma-Aldrich
GSK503, ≥98% (HPLC)
Sigma-Aldrich
Normal Mouse IgG, Normal Mouse IgG Polyclonal Antibody control validated for use in Immunoprecipitation & Western Blotting.
Sigma-Aldrich
Anti-trimethyl-Histone H3 (Lys27) Antibody, Upstate®, from rabbit
Sigma-Aldrich
Anti-p21/WAF1/Cip1 Antibody, Upstate®, from mouse
Sigma-Aldrich
Normal Rabbit IgG, Normal Rabbit IgG Polyclonal Antibody control validated for use in Immunoprecipitation & Western Blotting.