K-homology nuclear ribonucleoproteins regulate floral organ identity and determinacy in arabidopsis

PLoS Genet. 2015 Feb 6;11(2):e1004983. doi: 10.1371/journal.pgen.1004983. eCollection 2015 Feb.

Abstract

Post-transcriptional control is nowadays considered a main checking point for correct gene regulation during development, and RNA binding proteins actively participate in this process. Arabidopsis thaliana FLOWERING LOCUS WITH KH DOMAINS (FLK) and PEPPER (PEP) genes encode RNA-binding proteins that contain three K-homology (KH)-domain, the typical configuration of Poly(C)-binding ribonucleoproteins (PCBPs). We previously demonstrated that FLK and PEP interact to regulate FLOWERING LOCUS C (FLC), a central repressor of flowering time. Now we show that FLK and PEP also play an important role in the maintenance of the C-function during floral organ identity by post-transcriptionally regulating the MADS-box floral homeotic gene AGAMOUS (AG). Previous studies have indicated that the KH-domain containing protein HEN4, in concert with the CCCH-type RNA binding protein HUA1 and the RPR-type protein HUA2, facilitates maturation of the AG pre-mRNA. In this report we show that FLK and PEP genetically interact with HEN4, HUA1, and HUA2, and that the FLK and PEP proteins physically associate with HUA1 and HEN4. Taken together, these data suggest that HUA1, HEN4, PEP and FLK are components of the same post-transcriptional regulatory module that ensures normal processing of the AG pre-mRNA. Our data better delineates the roles of PEP in plant development and, for the first time, links FLK to a morphogenetic process.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • AGAMOUS Protein, Arabidopsis / genetics*
  • Arabidopsis / genetics*
  • Arabidopsis / growth & development
  • Arabidopsis Proteins / biosynthesis
  • Arabidopsis Proteins / genetics*
  • Flowers / genetics*
  • Flowers / growth & development
  • Gene Expression Regulation, Plant
  • MADS Domain Proteins / biosynthesis
  • MADS Domain Proteins / genetics*
  • Microscopy, Electron, Scanning
  • Morphogenesis
  • Phenotype
  • RNA-Binding Proteins / biosynthesis
  • RNA-Binding Proteins / genetics*
  • Reproduction / genetics

Substances

  • AGAMOUS Protein, Arabidopsis
  • Arabidopsis Proteins
  • At5g10140 protein, Arabidopsis
  • MADS Domain Proteins
  • PEPPER protein, Arabidopsis
  • RNA-Binding Proteins

Grants and funding

Funding for this work came from the Ministerio de Ciencia e Innovación of Spain (http://www.idi.mineco.gob.es) (grant BIO2009-11407 to AV) and National Science Foundation of USA (http://www.nsf.gov/) (grant IOS-1121055 to MFY) and Paul D. Saltman Endowed Chair in Science Education (http://biology.ucsd.edu/news/awards-and-honors/endowed-chairs.html) to MFY. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.