Arabidopsis eIF3e interacts with subunits of the ribosome, Cop9 signalosome and proteasome.

The roles of individual Eukaryotic translation Initiation Factor 3 (eIF3) subunits are largely unclear. Though some are essential, while others are thought to have regulatory roles. The "e" subunit, also known as Int-6, is a candidate for a regulatory subunit as it is not essential for translation initiation in yeasts. To further elucidate the roles of eIF3e, we have employed an interaction-trap screen using the yeast two-hybrid system. eIF3e interacts in yeast with subunits of the ribosome, COP9 signalosome and 26S proteasome. These interactions mesh well with our recent results which showed that eIF3e is degraded in a CSN-dependent, proteasome-dependent fashion, and inhibits translation when present in excess.