Identification and characterization of a homologue of human EIF5A isoform A in mouse

Abstract

The eukaryotic translation initiation factor 5A (EIF5A) protein is highly conserved in eukaryotes and possesses a particular amino acid residue named hypusine that is not found in others proteins. The hypusine is essential for its activity and it is produced by a post-translational modification. Initially, EIF5A was involved with the initiation of the translation, but recently it was shown that it acts on translation elongation process of polyproline motifs. Some studies have shown that EIF5A has important roles in nucleo-cytoplasmic shuttle, RNA decay, cell proliferation control and HIV-1 replication. In humans, four transcript variants for EIF5A are known (A, B, C and D), derived from alternative splicing associated with the first exon. The variants B, C and D encode for the canonical isoform B, the main studied isoform to date. It is predicted that the variant A is responsible for the establishment of an upstream start codon in frame to the start codon of the others variants. So, it is predicted that the variant A codes for an EIF5A with an extra 30 amino-acids on its amino-terminal end. Currently, there is no other information on human EIF5A isoform A and this project aims to investigate its identification in mouse.