Insights into eukaryotic translation initiation factor 5A: Its role and mechanisms in protein synthesis
Keying Guo, Jie Zhou
Abstract
The protein synthesis within eukaryotic cells is a complex process involving various translation factors. Among these factors, eukaryotic translation initiation factor 5 A (eIF5A) emerges as a crucial translation factor with high evolutionary conservation. eIF5A is unique as it is the only protein in eukaryotic cells containing the hypusine modification. Initially presumed to be a translation initiation factor, eIF5A was subsequently discovered to act mainly during the translation elongation phase. Notably, eIF5A facilitates the translation of peptide sequences containing polyproline stretches and exerts a universal regulatory effect on the elongation and termination phases of protein synthesis. Additionally, eIF5A indirectly affects various physiological processes within the cell by modulating the translation of specific proteins. This review provides a comprehensive overview of the structure, physiological functions, various post-translational modifications of eIF5A, and its association with various human diseases. The comparison between eIF5A and its bacterial homolog, EF-P, extends the discussion to the evolutionary conservation of eIF5A. This highlights its significance across different domains of life. • Summarized the structure and biochemical characteristics of eIF5A and demonstrated the uniqueness of eIF5A • Reviewed the modifications of eIF5A, and explored its evolutionary conservatism compared to the homologous protein EF-P • Reviewed the functions of eIF5A, indicating its role in mitochondrial homeostasis, cell cycle arrest, ribosomal arrest • Reviewed the role of eIF5A in human diseases, including diabetes, cancer, viral infections and neurodevelopmental disorders