Plant Genetics seminar

24Oct2018 15:00 - 16:00

Lecture

by Franziska Turck

Research Group Leader

Max Planck Institue for Plant Breeding Research

https://www.mpipz.mpg.de/turck

 

Transcription factors orchestrate epigenetic gene repression in plants”.

Abstract

Polycomb group repressive protein complexes (PRCs) are essential for transcriptional regulation in higher eukaryotes; they act through the establishment of repressive epigenetic marks at specific chromatin regions. A key research question remains how PRC complexes find their target regions. In Drosophila, PRC2, responsible for establishing H3K27me3, is recruited via several well described motifs present in Polycomb response elements (PREs). In mammals, PREs and associated motifs are less obvious, while PRC recruitment through long non-coding RNAs has gathered much attention. In plants, until recently, PRC recruitment by cis-elements or non-coding RNA was not described with the exception of a few case studies.

I will present evidence for general mechanisms of PRC1 and PRC2 recruitment by B3 domain transcription factors and TELOMERE REPEAT BINDING FACTORs (TRBs), respectively. RY-motifs and teloboxes, the cognate elements of these DNA-binding protein classes, distribute along H3K27me3 marked regions with a high likelihood of presence in gene bodies. Approximately a fifth of PcG target genes depends on the joint action of TRBs and PRC2 for H3K27me3 coverage and transcriptional repression, these genes are particularly enriched in teloboxes but relatively depleted in RY-motifs. In contrast, genes enriched for RY-motifs but depleted for teloboxes gain H3K27me3 in trb mutants suggesting that these motifs compete for enzymatic activities that stabilize H3K27me3. In conclusion, plant PREs appear to be discontinuous and composed of a set of motifs that act in partial redundancy allowing for a concerted regulation of distinct groups of Polycomb target genes.

Recent papers

Telobox motifs recruit CLF/SWN-PRC2 for H3K27me3 deposition via TRB factors in Arabidopsis.

Zhou Y, Wang Y, Krause K, Yang T, Dongus JA, Zhang Y, Turck F.

Nat Genet. 2018 May;50(5):638-644. doi: 10.1038/s41588-018-0109-9. 

Genome-wide mapping of transcriptional enhancer candidates using DNA and chromatin features in maize.

Oka R, Zicola J, Weber B, Anderson SN, Hodgman C, Gent JI, Wesselink JJ, Springer NM, Hoefsloot HCJ, Turck F, Stam M.

Genome Biol. 2017 Jul 21;18(1):137. doi: 10.1186/s13059-017-1273-4.

Ctf4-related protein recruits LHP1-PRC2 to maintain H3K27me3 levels in dividing cells in Arabidopsis thaliana.

Zhou Y, Tergemina E, Cui H, Förderer A, Hartwig B, Velikkakam James G, Schneeberger K, Turck F.

Proc Natl Acad Sci U S A. 2017 May 2;114(18):4833-4838. doi: 10.1073/pnas.1620955114. Epub 2017 Apr 20.

H2A monoubiquitination in Arabidopsis thaliana is generally independent of LHP1 and PRC2 activity.

Zhou Y, Romero-Campero FJ, Gómez-Zambrano Á, Turck F, Calonje M.

Genome Biol. 2017 Apr 12;18(1):69. doi: 10.1186/s13059-017-1197-z.

 

 

 

A1.04

  • Science Park 904

    Science Park 904 | 1098 XH Amsterdam
    +31 (0)20 525 8626

    Go to detailpage

Published by  Swammerdam Institute