An Arabidopsis homolog of RAPTOR/KOG1 is essential for early embryo development

Biochem Biophys Res Commun. 2005 Jan 28;326(4):844-50. doi: 10.1016/j.bbrc.2004.11.117.


The RAPTOR/KOG1 proteins are binding partners of the target of rapamycin (TOR) kinase that is present in all eucaryotes and plays a central role in the stimulation of cell growth and metabolism in response to nutrients. We show in this report that two genes are coding for RAPTOR/KOG1 homologs in the Arabidopsis and rice genomes. Disruption of the Arabidopsis AtRaptor1 gene leads to a very early arrest of embryo development whereas disruption of the AtRaptor2 gene, which is expressed at a lower level than AtRaptor1, has no visible effects on embryo and plant development. We also observed that mutations in the AtRaptor1 gene result in an earlier halt of embryo development than disruption of the AtTor gene.

MeSH terms

  • Amino Acid Sequence
  • Arabidopsis / cytology
  • Arabidopsis / embryology*
  • Arabidopsis / genetics
  • Arabidopsis / physiology*
  • Arabidopsis Proteins / chemistry
  • Arabidopsis Proteins / genetics*
  • Arabidopsis Proteins / physiology*
  • Gene Expression Regulation, Developmental
  • Gene Expression Regulation, Plant
  • Genes, Plant
  • Mutation
  • Protein Isoforms / chemistry
  • Protein Isoforms / genetics
  • Protein Isoforms / physiology
  • Seeds / cytology
  • Seeds / genetics
  • Seeds / physiology
  • Sequence Homology, Amino Acid


  • Arabidopsis Proteins
  • Protein Isoforms
  • Raptor1 protein, Arabidopsis
  • Raptor2 protein, Arabidopsis