Translation initiation factor eIF3 is a multi-subunit protein complex required for initiation of protein biosynthesis in eukaryotic cells. The complex promotes ribosome dissociation, the binding of the initiator methionyl-tRNA to the 40 S ribosomal subunit, and mRNA recruitment to the ribosome. The protein product from TIF31 genes in yeast is p135 which associates with the eIF3 but does not seem to be necessary for protein translation initiation .
Mutations in the mitochondrial CLU proteins have been shown to result in clustered mitochondria [PUBMED:12952081, PUBMED:9207087, PUBMED:9601101]. CLU proteins include Saccharomyces cerevisiae clustered mitochondria protein (Clu1p, alias translation initiation factor 31/TIF31p), Dictyostelium discoideum clustered mitochondria protein homologue (CluA), Caenorhabditis elegans clustered mitochondria protein homologue (CLUH/ Protein KIAA0664), Drosophila clueless (alias clustered mitochondria protein homologue), Arabidopsis clustered mitochondria protein (CLU, alias friendly mitochondria protein/FMT), and human clustered mitochondria protein homologue (CLUH).