High impact information on TRIP-1

• We now show that the BRI1 kinase domain phosphorylates Arabidopsis TRIP-1 on three specific sites in vitro (Thr-14, Thr-89 and either Thr-197 or Ser-198) [1].
• We previously cloned putative TRIP-1 homologs from bean and Arabidopsis and found that transgenic Arabidopsis plants expressing antisense TRIP-1 RNA exhibited a broad range of developmental defects including some morphological characteristics that resemble the phenotype of BR-deficient and -insensitive mutants [1].
• TRIP-1 is a WD domain protein that also functions as an essential subunit of the eIF3 eukaryotic translation initiation factor in animals, yeast and plants [1].
• The majority of genes (such as BRU1, CycD3, Lin6, OPR3, and TRIP-1) were identified by comparisons of BR-treated versus control-treated plants [2].
• In yeast, expression of a TRIP-1 homolog has also been closely associated with cell proliferation and progression through the cell cycle [3].

Biological context of TRIP-1

• These findings support a role for TRIP-1 in the molecular mechanisms of BR-regulated plant growth and development, possibly as a cytoplasmic substrate of the BRI1 receptor kinase [1].
• Expression of a plant gene with sequence similarity to animal TGF-beta receptor interacting protein is regulated by brassinosteroids and required for normal plant development [3].

References