Eukaryotic Translation Initiation Factor 4a3 (EIF4A3) Human Recombinant Protein

This gene encodes a member of the DEAD box protein family. DEAD box proteins, characterized by the conserved motif Asp-Glu-Ala-Asp (DEAD), are putative RNA helicases. They are implicated in a number of cellular processes involving alteration of RNA secondary structure, such as translation initiation, nuclear and mitochondrial splicing, and ribosome and spliceosome assembly. Based on their distribution patterns, some members of this family are believed to be involved in embryogenesis, spermatogenesis, and cellular growth and division. The protein encoded by this gene is a nuclear matrix protein. Its amino acid sequence is highly similar to the amino acid sequences of the translation initiation factors eIF4AI and eIF4AII, two other members of the DEAD box protein family. [provided by RefSeq, Jul 2008]

DDX48: ATP-dependent RNA helicase. Component of a splicing- dependent multiprotein exon junction complex (EJC) deposited at splice junction on mRNAs. The EJC is a dynamic structure consisting of a few core proteins and several more peripheral nuclear and cytoplasmic associated factors that join the complex only transiently either during EJC assembly or during subsequent mRNA metabolism. Core components of the EJC, that remains bound to spliced mRNAs throughout all stages of mRNA metabolism, functions to mark the position of the exon-exon junction in the mature mRNA and thereby influences downstream processes of gene expression including mRNA splicing, nuclear mRNA export, subcellular mRNA localization, translation efficiency and nonsense-mediated mRNA decay (NMD). Constitutes at least part of the platform anchoring other EJC proteins to spliced mRNAs. Its RNA-dependent ATPase and RNA-helicase activities are induced by CASC3, but abolished in presence of the MAGOH/RBM8A heterodimer, thereby trapping the ATP- bound EJC core onto spliced mRNA in a stable conformation. The inhibition of ATPase activity by the MAGOH/RBM8A heterodimer increases the RNA-binding affinity of the EJC. Involved in translational enhancement of spliced mRNAs after formation of the 80S ribosome complex. Binds spliced mRNA in sequence-independent manner, 20-24 nucleotides upstream of mRNA exon-exon junctions. Shows higher affinity for single-stranded RNA in an ATP-bound core EJC complex than after the ATP is hydrolyzed. Belongs to the DEAD box helicase family. eIF4A subfamily.

Protein type: RNA splicing; Helicase; Spliceosome; EC 3.6.4.13; RNA-binding

Chromosomal Location of Human Ortholog: 17q25.3

Cellular Component: nucleoplasm; membrane; cytoplasm; nuclear speck; cytosol

Molecular Function: mRNA binding; protein binding; poly(A) binding; ATP-dependent RNA helicase activity; ATP binding

Biological Process: nuclear mRNA splicing, via spliceosome; poly(A) tail shortening; mRNA transport; positive regulation of translation; negative regulation of translation; cytokine and chemokine mediated signaling pathway; mRNA catabolic process, nonsense-mediated decay; gene expression; embryonic cranial skeleton morphogenesis; rRNA processing; mRNA catabolic process, deadenylation-dependent decay

Disease: Robin Sequence With Cleft Mandible And Limb Anomalies