eIF5A

eIF5A, or eukaryotic translation initiation factor 5A, is a highly conserved protein found in all eukaryotes. It plays a crucial role in protein synthesis, specifically during the translation initiation and elongation phases. eIF5A is unique among cellular proteins due to its post-translational modification, hypusination, which involves the addition of a deoxyhypusine moiety to a specific lysine residue. This modification is essential for its function and is catalyzed by deoxyhypusine synthase and deoxyhypusine hydroxylase.

The primary function of eIF5A is to facilitate the binding of messenger RNA (mRNA) to the ribosome and promote the formation of the 80S initiation complex. It is thought to do this by interacting with both mRNA and the ribosome, and by stabilizing the mRNA structure. Beyond its canonical role in translation, eIF5A has also been implicated in a growing number of other cellular processes, including RNA processing, nuclear export, and the regulation of gene expression. Its involvement in these diverse functions suggests a broader regulatory capacity than initially understood. Dysregulation of eIF5A has been linked to various diseases, including cancer and viral infections, highlighting its importance in cellular homeostasis and disease pathogenesis. Research continues to elucidate the full spectrum of eIF5A's functions and its involvement in cellular processes.