Regulation of the interactions between human eIF5 and eIF1A by the CK2 kinase.

Translation initiation in eukaryotes relies on a complex network of interactions that are continuously reorganized throughout the process. As more information becomes available about the structure of the ribosomal preinitiation complex (PIC) at various points in translation initiation, new questions arise about which interactions occur when, their roles, and regulation. The eukaryotic translation factor (eIF) 5 is the GTPase-activating protein (GAP) for the GTPase eIF2, which brings the initiator Met-tRNA to the PIC.

The PCI domains are "winged" HEAT domains.

The HEAT domains are a family of helical hairpin repeat domains, composed of four or more hairpins. HEAT is derived from the names of four family members: huntingtin, eukaryotic translation elongation factor 3 (eEF3), protein phosphatase 2 regulatory A subunit (PP2A), and mechanistic target of rapamycin (mTOR). HEAT domain-containing proteins play roles in a wide range of cellular processes, such as protein synthesis, nuclear transport and metabolism, and cell signaling.

Dynamic interaction network involving the conserved intrinsically disordered regions in human eIF5.

Translation initiation in eukaryotes requires multiple eukaryotic translation initiation factors (eIFs) and involves continuous remodeling of the ribosomal preinitiation complex (PIC). The GTPase eIF2 brings the initiator Met-tRNA to the PIC. Upon start codon selection and GTP hydrolysis, promoted by eIF5, eIF2-GDP is released in complex with eIF5.