Head-to-tail polymerization by VEL proteins underpins cold-induced Polycomb silencing in flowering control

DOI: 10.1016/j.celrep.2022.111607

Authors: Marc Fiedler (MRC Laboratory of Molecular Biology) , Elsa Franco-Echevarria (MRC Laboratory of Molecular Biology) , Anna Schulten (John Innes Centre) , Mathias Nielsen (John Innes Centre) , Trevor J. Rutherford (MRC Laboratory of Molecular Biology) , Anna Yeates (MRC Laboratory of Molecular Biology) , Bilal Ahsan (MRC Laboratory of Molecular Biology) , Caroline Dean (MRC Laboratory of Molecular Biology; John Innes Centre) , Mariann Bienz (MRC Laboratory of Molecular Biology)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Cell Reports , VOL 41

State: Published (Approved)
Published: November 2022
Diamond Proposal Number(s): 21426

Abstract: Transcriptional silencing through the Polycomb silencing machinery utilizes a “read-write” mechanism involving histone tail modifications. However, nucleation of silencing and long-term stable transmission of the silenced state also requires P-olycomb Repressive Complex 2 (PRC2) accessory proteins, whose molecular role is poorly understood. The Arabidopsis VEL proteins are accessory proteins that interact with PRC2 to nucleate and propagate silencing at the FLOWERING LOCUS C (FLC) locus, enabling early flowering in spring. Here, we report that VEL proteins contain a domain related to an atypical four-helix bundle that engages in spontaneous concentration-dependent head-to-tail polymerization to assemble dynamic biomolecular condensates. Mutations blocking polymerization of this VEL domain prevent Polycomb silencing at FLC. Plant VEL proteins thus facilitate assembly of dynamic multivalent Polycomb complexes required for inheritance of the silenced state.

Journal Keywords: head-to-tail polymerization; biomolecular condensation; atypical four-helix bundle; DNAJ co-chaperones; Polycomb silencing; inheritance of repressed state; cold-induced flowering control

Subject Areas: Biology and Bio-materials


Instruments: I04-Macromolecular Crystallography , I24-Microfocus Macromolecular Crystallography

Added On: 09/11/2022 11:41

Documents:
1-s2.0-S2211124722014760-main.pdf

Discipline Tags:

Plant science Structural biology Life Sciences & Biotech

Technical Tags:

Diffraction Macromolecular Crystallography (MX)