BioProject

Regulation of translation initiation is accomplished in diverse eukaryotes through proteins which bind to the mRNA cap-binding protein, eIF4E, and either prevent its association with eIF4G or form repressive mRNPs which exclude the translation machinery. More...

Regulation of translation initiation is accomplished in diverse eukaryotes through proteins which bind to the mRNA cap-binding protein, eIF4E, and either prevent its association with eIF4G or form repressive mRNPs which exclude the translation machinery. Such mechanisms in plants, and even the presence of eIF4E-interacting proteins outside of eIF4G (and the plant-specific isoform eIFiso4G, which binds eIFiso4E) which operate in a gene regulatory manner are not known. Here we describe the Conserved Binding of eIF4E 1 (CBE1), a plant-specific protein with an evolutionarily conserved eIF4E binding motif. This protein binds eIF4E or eIFiso4E in vitro to form cap-binding complexes, and is found as a constituent of cap-binding complexes in vivo in an eIF4E-dependent manner. Mutants lacking CBE1 show dysregulation of cell cycle related transcripts, accumulating higher levels relative to wild-type plants of mRNAs encoding proteins involved in mitotic processes. These findings support CBE1 as a plant protein with the capability to form cap-binding complexes with the potential for gene regulatory activity. Overall design: poly(A) RNA fraction was purified and sequenced from homogenized 7-day-old seedling tissue, grown under long day conditions on 1% sucrose MS plates, with three biological replicates of Col0 (wild-type) or cbe1 mutant Less...