Component of the eukaryotic translation initiation factor 3 (eIF-3) complex, which is involved in protein synthesis of a specialized repertoire of mRNAs and, together with other initiation factors, stimulates binding of mRNA and methionyl-tRNAi to the 40S ribosome. The eIF-3 complex specifically targets and initiates translation of a subset of mRNAs involved in cell proliferation (Potential). Regulates negatively translation during flower development (PubMed:18067529, PubMed:20444226). Component of the eukaryotic translation initiation factor 3 (eIF-3) complex (Potential). Binds to the translation initiation factors TIF3F1 and TIF3H1 (PubMed:20444226, PubMed:15548739). Associates with the CSN (COP9 signalosome) complex. Interacts directly with CSN1, CSN4, CSN6A, CSN6B, CSN7, CSN8 and TIF3C1 (PubMed:11029466, PubMed:19704582). Binds to 40S small ribosomal subunit S9 (RPS9B and RPS9C) via its N-terminal part. Interacts with the 26S proteasome subunit RPN12a via its C-terminal part. Binds also with At1g27930 and At4g30620 (PubMed:19704582). Targeted by the COP9 signalosome to proteasome-dependent degradation. Several floral development defects, including delayed flowering, reduced sepaloid petals and short stamens. Male gametophytic lethal. The PCI domain is protease-resistant. Belongs to the eIF-3 subunit E family.