Q3B8Q2 (IF4A3_RAT) Reviewed, UniProtKB/Swiss-Prot
Last modified November 13, 2013. Version 58. History...
Names and origin
|Protein names||Recommended name:|
Eukaryotic initiation factor 4A-III
ATP-dependent RNA helicase DDX48
ATP-dependent RNA helicase eIF4A-3
DEAD box protein 48
Eukaryotic translation initiation factor 4A isoform 3
Cleaved into the following chain:
|Organism||Rattus norvegicus (Rat) [Reference proteome]|
|Taxonomic identifier||10116 [NCBI]|
|Taxonomic lineage||Eukaryota › Metazoa › Chordata › Craniata › Vertebrata › Euteleostomi › Mammalia › Eutheria › Euarchontoglires › Glires › Rodentia › Sciurognathi › Muroidea › Muridae › Murinae › Rattus|
|Sequence length||411 AA.|
|Sequence processing||The displayed sequence is further processed into a mature form.|
|Protein existence||Evidence at protein level|
General annotation (Comments)
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 By similarity.
ATP + H2O = ADP + phosphate.
The ATPase activity is increased in the presence of RNA By similarity.
Part of the EJC core complex that contains CASC3, EIF4A3, MAGOH and RBM8A. Found in a mRNA splicing-dependent exon junction complex (EJC), at least composed of ACIN1, CASC3, EIF4A3, MAGOH, PNN, RBM8A, RNPS1, SAP18 and ALYREF/THOC4. Interacts with CASC3, MAGOH, NXF1, RBM8A and ALYREF/THOC4. Identified in the spliceosome C complex. May interact with NOM1 By similarity. Interacts with CWC22 and PRPF19 in an RNA-independent manner. Direct interaction with CWC22 is mediated by the helicase C-terminal domain. Full interaction with CWC22 occurs only when EIF4A3 is not part of the EJC and prevents EIF4A3 binding to RNA By similarity.
Nucleus. Nucleus speckle By similarity. Cytoplasm. Note: Nucleocytoplasmic shuttling protein. Travels to the cytoplasm as part of the exon junction complex (EJC) bound to mRNA By similarity. Detected in dendritic layer as well as the nuclear and cytoplasmic (somatic) compartments of neurons. Colocalizes with STAU1 and FMR1 in dendrites. Ref.3
Expressed in the CA1 field and dentate gyrus of the hippocampus (at protein level).
Contains 1 helicase ATP-binding domain.
Contains 1 helicase C-terminal domain.
Sequence annotation (Features)
|Feature key||Position(s)||Length||Description||Graphical view||Feature identifier|
|Chain||1 – 411||411||Eukaryotic initiation factor 4A-III||PRO_0000378555|
|Initiator methionine||1||1||Removed; alternate By similarity|
|Chain||2 – 411||410||Eukaryotic initiation factor 4A-III, N-terminally processed||PRO_0000423271|
|Domain||69 – 239||171||Helicase ATP-binding|
|Domain||250 – 411||162||Helicase C-terminal|
|Nucleotide binding||85 – 90||6||ATP By similarity|
|Nucleotide binding||367 – 371||5||ATP By similarity|
|Motif||38 – 66||29||Q motif|
|Motif||187 – 190||4||DEAD box|
|Binding site||60||1||ATP; via carbonyl oxygen By similarity|
|Binding site||65||1||ATP By similarity|
|Binding site||342||1||ATP By similarity|
Amino acid modifications
|Modified residue||1||1||N-acetylmethionine By similarity|
|Modified residue||2||1||N-acetylalanine; in Eukaryotic initiation factor 4A-III, N-terminally processed By similarity|
|Modified residue||12||1||Phosphoserine By similarity|
|Modified residue||163||1||Phosphothreonine By similarity|
|Modified residue||296||1||N6-acetyllysine By similarity|
|Modified residue||321||1||N6-acetyllysine By similarity|
|||Mural R.J., Adams M.D., Myers E.W., Smith H.O., Venter J.C.|
Submitted (JUL-2005) to the EMBL/GenBank/DDBJ databases
Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
Strain: Brown Norway.
|||"The status, quality, and expansion of the NIH full-length cDNA project: the Mammalian Gene Collection (MGC)."|
The MGC Project Team
Genome Res. 14:2121-2127(2004) [PubMed] [Europe PMC] [Abstract]
Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE MRNA].
|||"The EJC factor eIF4AIII modulates synaptic strength and neuronal protein expression."|
Giorgi C., Yeo G.W., Stone M.E., Katz D.B., Burge C., Turrigiano G., Moore M.J.
Cell 130:179-191(2007) [PubMed] [Europe PMC] [Abstract]
Cited for: SUBCELLULAR LOCATION.
|BC105875 mRNA. Translation: AAI05876.1.|
CH473948 Genomic DNA. Translation: EDM06783.1.
|RefSeq||NP_001093628.1. NM_001100158.2. |
3D structure databases
|SMR||Q3B8Q2. Positions 21-411. |
Protocols and materials databases
Genome annotation databases
|Ensembl||ENSRNOT00000073140; ENSRNOP00000066302; ENSRNOG00000045791. |
|RGD||1591139. Eif4a3. |
Gene expression databases
Family and domain databases
|InterPro||IPR011545. DNA/RNA_helicase_DEAD/DEAH_N. |
|Pfam||PF00270. DEAD. 1 hit. |
PF00271. Helicase_C. 1 hit.
|SMART||SM00487. DEXDc. 1 hit. |
SM00490. HELICc. 1 hit.
|SUPFAM||SSF52540. SSF52540. 1 hit. |
|PROSITE||PS00039. DEAD_ATP_HELICASE. 1 hit. |
PS51192. HELICASE_ATP_BIND_1. 1 hit.
PS51194. HELICASE_CTER. 1 hit.
PS51195. Q_MOTIF. 1 hit.
|Accession||Primary (citable) accession number: Q3B8Q2|
|Entry status||Reviewed (UniProtKB/Swiss-Prot)|
|Annotation program||Chordata Protein Annotation Program|