RT Journal Article
SR Electronic
T1 A role for MED14 and UVH6 in heterochromatin transcription upon destabilization of silencing
JF Life Science Alliance
JO Life Sci. Alliance
FD Life Science Alliance LLC
SP e201800197
DO 10.26508/lsa.201800197
VO 1
IS 6
A1 Pierre Bourguet
A1 Stève de Bossoreille
A1 Leticia López-González
A1 Marie-Noëlle Pouch-Pélissier
A1 Ángeles Gómez-Zambrano
A1 Anthony Devert
A1 Thierry Pélissier
A1 Romain Pogorelcnik
A1 Isabelle Vaillant
A1 Olivier Mathieu
YR 2018
UL https://www.life-science-alliance.org/content/1/6/e201800197.abstract
AB Constitutive heterochromatin is associated with repressive epigenetic modifications of histones and DNA which silence transcription. Yet, particular mutations or environmental changes can destabilize heterochromatin-associated silencing without noticeable changes in repressive epigenetic marks. Factors allowing transcription in this nonpermissive chromatin context remain poorly known. Here, we show that the transcription factor IIH component UVH6 and the mediator subunit MED14 are both required for heat stress–induced transcriptional changes and release of heterochromatin transcriptional silencing in Arabidopsis thaliana. We find that MED14, but not UVH6, is required for transcription when heterochromatin silencing is destabilized in the absence of stress through mutating the MOM1 silencing factor. In this case, our results raise the possibility that transcription dependency over MED14 might require intact patterns of repressive epigenetic marks. We also uncover that MED14 regulates DNA methylation in non-CG contexts at a subset of RNA-directed DNA methylation target loci. These findings provide insight into the control of heterochromatin transcription upon silencing destabilization and identify MED14 as a regulator of DNA methylation.