Dual role for fimbriata in regulating floral homeotic genes and cell division in Antirrhinum

EMBO J. 1997 Nov 3;16(21):6521-34. doi: 10.1093/emboj/16.21.6521.


The fimbriata (fim) gene of Antirrhinum affects both the identity and arrangement of organs within the flower, and encodes a protein with an F-box motif. We show that FIM associates with a family of proteins, termed FAPs (FIM-associated proteins), that are closely related to human and yeast Skp1 proteins. These proteins form complexes with F-box-containing partners to promote protein degradation and cell cycle progression. The fap genes are expressed in inflorescence and floral meristems in a pattern that incorporates the domain of fim expression, supporting an in vivo role for a FIM-FAP complex. Analysis of a series of novel fim alleles shows that fim plays a key role in the activation of organ identity genes. In addition, fim acts in the regions between floral organs to specify the correct positioning and maintenance of morphological boundaries. Taking these results together, we propose that FIM-FAP complexes affect both gene expression and cell division, perhaps by promoting selective degradation of regulatory proteins. This may provide a mechanism by which morphological boundaries can be aligned with domains of gene expression during floral development.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Base Sequence
  • DEFICIENS Protein
  • Gene Expression Regulation, Plant*
  • Genes, Homeobox*
  • Genes, Plant*
  • Homeodomain Proteins / biosynthesis
  • Homeodomain Proteins / genetics
  • Humans
  • Molecular Sequence Data
  • Morphogenesis / genetics
  • Mosaicism
  • Mutagenesis, Site-Directed
  • Organ Specificity
  • Plant Proteins / genetics
  • Plant Proteins / physiology*
  • Plants / genetics*
  • Saccharomyces cerevisiae / genetics
  • Sequence Alignment
  • Sequence Homology
  • Species Specificity


  • DEFICIENS Protein
  • FIM protein, Antirrhinum majus
  • GLOBOSA protein, plant
  • Homeodomain Proteins
  • Plant Proteins

Associated data

  • GENBANK/Y14856
  • GENBANK/Y14857
  • GENBANK/Y14858