Eukaryotic initiation factor 4A-III is a protein that in humans is encoded by the EIF4A3 gene. [5] [6] [7]
Eukaryotic initiation factor 4A-III is a protein that in humans is encoded by the EIF4A3 gene. [5] [6] [7]
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 eIF4A-I and eIF4A-II, two other members of the DEAD box protein family. [7]
RNA splicing is a process in molecular biology where a newly-made precursor messenger RNA (pre-mRNA) transcript is transformed into a mature messenger RNA (mRNA). It works by removing all the introns and splicing back together exons. For nuclear-encoded genes, splicing occurs in the nucleus either during or immediately after transcription. For those eukaryotic genes that contain introns, splicing is usually needed to create an mRNA molecule that can be translated into protein. For many eukaryotic introns, splicing occurs in a series of reactions which are catalyzed by the spliceosome, a complex of small nuclear ribonucleoproteins (snRNPs). There exist self-splicing introns, that is, ribozymes that can catalyze their own excision from their parent RNA molecule. The process of transcription, splicing and translation is called gene expression, the central dogma of molecular biology.
Nonsense-mediated mRNA decay (NMD) is a surveillance pathway that exists in all eukaryotes. Its main function is to reduce errors in gene expression by eliminating mRNA transcripts that contain premature stop codons. Translation of these aberrant mRNAs could, in some cases, lead to deleterious gain-of-function or dominant-negative activity of the resulting proteins.
RNA-binding protein 8A is a protein that in humans is encoded by the RBM8A gene.
Regulator of nonsense transcripts 1 is a protein that in humans is encoded by the UPF1 gene.
Spliceosome RNA helicase BAT1 is an enzyme that in humans is encoded by the BAT1 gene.
Eukaryotic translation initiation factor 2 subunit 2 (eIF2β) is a protein that in humans is encoded by the EIF2S2 gene.
Regulator of nonsense transcripts 3B is a protein that in humans is encoded by the UPF3B gene.
Aly/REF export factor, also known as THO complex subunit 4 is a protein that in humans is encoded by the ALYREF gene.
Protein mago nashi homolog is a protein that in humans is encoded by the MAGOH gene.
Splicing factor, arginine/serine-rich 4 is a protein that in humans is encoded by the SFRS4 gene.
Eukaryotic translation initiation factor 2 subunit 3 (eIF2γ) is a protein that in humans is encoded by the EIF2S3 gene.
Far upstream element-binding protein 2 is a protein that in humans is encoded by the KHSRP gene.
Eukaryotic translation initiation factor 5 is a protein that in humans is encoded by the EIF5 gene.
U4/U6 small nuclear ribonucleoprotein Prp4 is a protein that in humans is encoded by the PRPF4 gene. The removal of introns from nuclear pre-mRNAs occurs on complexes called spliceosomes, which are made up of 4 small nuclear ribonucleoprotein (snRNP) particles and an undefined number of transiently associated splicing factors. PRPF4 is 1 of several proteins that associate with U4 and U6 snRNPs.[supplied by OMIM]
Protein CASC3 is a protein that in humans is encoded by the CASC3 gene.
Eukaryotic translation initiation factor 4H is a protein that in humans is encoded by the EIF4H gene.
Regulator of nonsense transcripts 3A is a protein that in humans is encoded by the UPF3A gene.
RNA binding motif protein 9 (RBM9), also known as Rbfox2, is a protein which in humans is encoded by the RBM9 gene.
Eukaryotic translation initiation factor 4E transporter is a protein that in humans is encoded by the EIF4ENIF1 gene.
An exon junction complex (EJC) is a protein complex which forms on a pre-messenger RNA strand at the junction of two exons which have been joined together during RNA splicing. The EJC has major influences on translation, surveillance, localization of the spliced mRNA, and m6A methylation. It is first deposited onto mRNA during splicing and is then transported into the cytoplasm. There it plays a major role in post-transcriptional regulation of mRNA. It is believed that exon junction complexes provide a position-specific memory of the splicing event. The EJC consists of a stable heterotetramer core, which serves as a binding platform for other factors necessary for the mRNA pathway. The core of the EJC contains the protein eukaryotic initiation factor 4A-III bound to an adenosine triphosphate (ATP) analog, as well as the additional proteins Magoh and Y14. The binding of these proteins to nuclear speckled domains has been measured recently and it may be regulated by PI3K/AKT/mTOR signaling pathways. In order for the binding of the complex to the mRNA to occur, the eIF4AIII factor is inhibited, stopping the hydrolysis of ATP. This recognizes EJC as an ATP dependent complex. EJC also interacts with a large number of additional proteins; most notably SR proteins. These interactions are suggested to be important for mRNA compaction. The role of EJC in mRNA export is controversial.
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