Eukaryotic translation initiation factor 1A, X-chromosomal

EIF1AX (eukaryotic translation initiation factor 1A, X-chromosomal) is a 144-amino acid protein that functions as a core component of the 43S pre-initiation complex (UniProt: P47813). It facilitates mRNA cap recognition, scanning of the 5'-untranslated region, and start codon identification. Working with other initiation factors, EIF1AX promotes assembly of the 48S complex and, following start codon location, helps orient the initiator methionine-tRNA to enable 60S ribosomal subunit joining and formation of the 80S initiation complex.

EIF1AX is a ubiquitous translation factor essential for protein synthesis initiation across tissues. The UniProt record lists no established disease associations in its curated annotations (UniProt: P47813).

In Alzheimer's Disease, EIF1AX is upregulated in post-mortem AD brain tissue relative to age-matched controls (Chaparral AD proteomics). The mean log2 fold-change is 0.6835 across one subcellular fraction in TMT-labeled quantitative proteomics analysis of four subcellular fractions from human AD brain. This elevation may reflect altered translational control mechanisms in the diseased state, though the functional significance of this change remains to be determined.