EIF1AX
Description
The EIF1AX (eukaryotic translation initiation factor 1A X-linked) is a protein-coding gene located on chromosome X.
EIF1AX is a gene encoding eukaryotic translation initiation factor 1A, X-chromosomal (eIF1A). This protein is essential for translation initiation and is part of the 43S pre-initiation complex (PIC) which recruits the small 40S ribosomal subunit to the 5' cap of messenger RNAs. EIF1A binds near the ribosomal A-site, similar to the bacterial counterpart IF1. Mutations in this gene have been linked to uveal melanoma with disomy 3 and thyroid cancers. EIF1AX interacts with IPO13.
EIF1AX is a crucial component of the 43S pre-initiation complex (43S PIC). This complex initiates protein synthesis by binding to the mRNA cap-proximal region, scanning the 5'-untranslated region, and locating the initiation codon. EIF1AX enhances the formation of the cap-proximal complex and, alongside EIF1, facilitates the scanning process, start codon recognition, and assembly of the 48S complex. It also promotes the dissociation of aberrant complexes. Upon locating the start codon, EIF1AX collaborates with EIF5B to orient the initiator methionine-tRNA, facilitating the joining of the 60S ribosomal subunit to form the 80S initiation complex. EIF1AX is released after the 80S initiation complex formation, shortly after GTP hydrolysis by EIF5B, and before the release of EIF5B. Its globular portion resides in the A site of the 40S ribosomal subunit. EIF1AX interacts with EIF5 during scanning, contributing to the retention of EIF1 within the open 43S PIC. Notably, unlike its yeast counterparts, EIF1AX does not bind to EIF1.
EIF1AX is also known as EIF1A, EIF1AP1, EIF4C, eIF-1A, eIF-4C.
