EIF4A3
Description
The EIF4A3 (eukaryotic translation initiation factor 4A3) is a protein-coding gene located on chromosome 17.
EIF4A3 is a gene that encodes a protein called eukaryotic initiation factor 4A-III, which belongs to the DEAD box protein family. DEAD box proteins are RNA helicases involved in various cellular processes related to RNA structure modification, such as translation initiation, splicing, and ribosome assembly. EIF4A3 is a nuclear matrix protein, and its amino acid sequence is similar to other DEAD box proteins, including translation initiation factors eIF4A-I and eIF4A-II.
EIF4A3 is an ATP-dependent RNA helicase that plays a crucial role in pre-mRNA splicing as a component of the spliceosome. It is a core component of the exon junction complex (EJC), a multiprotein complex deposited at splice junctions on mRNAs. The EJC marks the position of the exon-exon junction in the mature mRNA, guiding downstream processes like nuclear mRNA export, subcellular mRNA localization, translation efficiency, and nonsense-mediated mRNA decay (NMD). EIF4A3's RNA-dependent ATPase and RNA-helicase activities are regulated by interacting proteins, with CASC3 activating them and MAGOH-RBM8A inhibiting them, leading to stable EJC binding on spliced mRNA. EIF4A3 is involved in translational enhancement of spliced mRNAs and binds to spliced mRNA upstream of exon-exon junctions. It shows a higher affinity for single-stranded RNA in an ATP-bound EJC complex. EIF4A3 also plays a role in splicing modulation of apoptotic genes, particularly BCL2L1/Bcl-X, by inhibiting the formation of proapoptotic isoforms. Additionally, EIF4A3 is implicated in craniofacial development.
EIF4A3 is also known as DDX48, Fal1, MUK34, NMP265, NUK34, RCPS, eIF-4A-III, eIF4A-III, eIF4AIII.
