Function and Mechanism of Eukaryotic Translation Initiation Factor 5A in Protein Synthesis / 中国生物化学与分子生物学报

ABSTRACT

In addition to the ribosome, aminoacyl-tRNA, and mRNA, translation factors are also necessary for protein synthesis.The eukaryotic translation initiation factor 5 A (eIF5A) is essential for cell viability and well conserved in all three domains during evolution.It is the only protein in eukaryotic cells that contains the unusual amino acid hypusine and the unique post-translational modification of eIF5A is strictly required for its function.eIF5A was identified in 1978 for the first time and was thought to stimulate the formation of the first peptide bond during translation initiation phase.Its involvement in the translation of polyproline-containing protein was not uncovered until 2013.With the research of over 40 years, our understanding of eIF5A function has changed dramatically.Recent ribosome profile data demonstrate that eIF5A works more generally at many ribosome stalled sites, and not limited to polyproline motif.It also enhances translation termination by facilitating peptide release.Moreover, eIF5A also indirectly regulates various cell life activities by controlling the translation of certain proteins.In this review, we provide a summary of the post-translational modification, the regulating effects during protein synthesis and autophagy as well as the relationship between eIF5A and human diseases, and explore the evolutionary conservation of eIF5A by comparing with the bacterial and arehaeal orthologs, so as to provide a theoretical basis for the research in related fields.