Content area
Full text
About the Authors:
Dong-Hwan Kim
Roles Conceptualization, Formal analysis, Methodology, Validation, Writing - original draft, Writing - review & editing
Affiliation: Department of Molecular Biosciences and Institute for Cellular and Molecular Biology, the University of Texas at Austin, TX, United States of America
Yanpeng Xi
Roles Data curation, Formal analysis, Investigation, Methodology, Validation, Visualization, Writing - original draft
Affiliation: Department of Molecular Biosciences and Institute for Cellular and Molecular Biology, the University of Texas at Austin, TX, United States of America
ORCID http://orcid.org/0000-0002-5938-4307
Sibum Sung
Roles Conceptualization, Funding acquisition, Investigation, Project administration, Supervision, Writing - original draft, Writing - review & editing
* E-mail: [email protected]
Affiliation: Department of Molecular Biosciences and Institute for Cellular and Molecular Biology, the University of Texas at Austin, TX, United States of America
ORCID http://orcid.org/0000-0003-2980-9009Abstract
The long noncoding RNA COLDAIR is necessary for the repression of a floral repressor FLOWERING LOCUS C (FLC) during vernalization in Arabidopsis thaliana. The repression of FLC is mediated by increased enrichment of Polycomb Repressive Complex 2 (PRC2) and subsequent trimethylation of Histone H3 Lysine 27 (H3K27me3) at FLC chromatin. In this study we found that the association of COLDAIR with chromatin occurs only at the FLC locus and that the central region of the COLDAIR transcript is critical for this interaction. A modular motif in COLDAIR is responsible for the association with PRC2 in vitro, and the mutations within the motif that reduced the association of COLDAIR with PRC2 resulted in vernalization insensitivity. The vernalization insensitivity caused by mutant COLDAIR was rescued by the ectopic expression of the wild-type COLDAIR. Our study reveals the molecular framework in which COLDAIR lncRNA mediates the PRC2-mediated repression of FLC during vernalization.
Author summary
Vernalization is an epigenetic response to winter cold necessary for the onset of flowering in spring. The epigenetically stable repression of a floral repressor, FLC, is a hallmark of the vernalization response in the model plant Arabidopsis. Vernalization-mediated repression of FLC is achieved by coordination among chromatin-modifying complexes and several long noncoding RNAs (lncRNAs). COLDAIR is an intronic lncRNA that is transcribed from the first intron of FLC and is necessary for the enrichment of PRC2 at the FLC locus. We found that COLDAIR is enriched only at FLC chromatin within the COLDAIR-enriched region....