MSI4/FVE interacts with CUL4-DDB1 and a PRC2-like complex to control epigenetic regulation of flowering time in Arabidopsis

Proc Natl Acad Sci U S A. 2011 Feb 22;108(8):3430-5. doi: 10.1073/pnas.1018242108. Epub 2011 Jan 31.

Abstract

Flowering at the right time is crucial to ensure successful plant reproduction and seed yield and is dependent on both environmental and endogenous parameters. Among the different pathways that impinge on flowering, the autonomous pathway promotes floral transition independently of day length through the repression of the central flowering repressor flowering locus C (FLC). FLC blocks floral transition by repressing flowering time integrators such as flowering locus T (FT). MSI4/FVE is a key regulator of the autonomous pathway that reduces FLC expression. Here we report that the MSI4 protein is a DDB1 and CUL4-associated factor that represses FLC expression through its association with a CLF-Polycomb Repressive Complex 2 (PRC2) in Arabidopsis. Thus, the lack of MSI4 or decreased CUL4 activity reduces H3K27 trimethylation on FLC, but also on its downstream target FT, resulting in increased expression of both genes. Moreover, CUL4 interacts with FLC chromatin in an MSI4-dependant manner, and the interaction between MSI4 and CUL4-DDB1 is necessary for the epigenetic repression of FLC. Overall our work provides evidence for a unique functional interaction between the cullin-RING ubiquitin ligase (CUL4-DDB1(MSI4)) and a CLF-PRC2 complex in the regulation of flowering timing in Arabidopsis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Arabidopsis / genetics*
  • Arabidopsis / physiology
  • Arabidopsis Proteins / genetics
  • Arabidopsis Proteins / metabolism*
  • Arabidopsis Proteins / physiology
  • Carrier Proteins / metabolism*
  • Carrier Proteins / physiology
  • Cullin Proteins / metabolism*
  • Cullin Proteins / physiology
  • DNA-Binding Proteins / metabolism*
  • DNA-Binding Proteins / physiology
  • Epigenomics*
  • Flowers / genetics*
  • Gene Expression Regulation, Plant
  • Histones / metabolism
  • MADS Domain Proteins / genetics
  • Methylation
  • Transcription Factors

Substances

  • Arabidopsis Proteins
  • CULLIN4 protein, Arabidopsis
  • Carrier Proteins
  • Cullin Proteins
  • DDB1a protein, Arabidopsis
  • DNA-Binding Proteins
  • FLF protein, Arabidopsis
  • Histones
  • MADS Domain Proteins
  • MSI4 protein, Arabidopsis
  • Transcription Factors