Protein-coding gene in the species Homo sapiens
NXF1 |
---|
|
Available structures |
---|
PDB | Ortholog search: PDBe RCSB |
---|
List of PDB id codes |
---|
4WYK, 1FO1, 1FT8, 1GO5, 1JKG, 1JN5, 1KOH, 1KOO, 1OAI, 2Z5K, 2Z5M, 3RW6, 3RW7 |
|
|
Identifiers |
---|
Aliases | NXF1, MEX67, TAP, nuclear RNA export factor 1 |
---|
External IDs | OMIM: 602647 MGI: 1858330 HomoloGene: 38176 GeneCards: NXF1 |
---|
|
|
|
|
|
Wikidata |
|
Nuclear RNA export factor 1, also known as NXF1 or TAP, is a protein which in humans is encoded by the NXF1 gene.[5][6]
Function
This gene is one member of a family of nuclear RNA export factor genes. Common domain features of this family are a noncanonical RNP-type RNA-binding domain (RBD), 4 leucine-rich repeats (LRRs), a nuclear transport factor 2 (NTF2)-like domain that allows heterodimerization with NTF2-related export protein-1 (NXT1), and a ubiquitin-associated domain that mediates interactions with nucleoporins. Alternative splicing results in transcript variants. The LRRs and NTF2-like domains are required for export activity. The encoded protein of this gene shuttles between the nucleus and the cytoplasm and binds in vivo to poly(A)+ RNA. It is the vertebrate homologue of the yeast protein Mex67p.[6][7] The encoded protein overcomes the mRNA export block caused by the presence of saturating amounts of CTE (constitutive transport element) RNA of type D retroviruses.[8] A variant allele of the homologous Nxf1 gene in mice suppresses a class of mutations caused by integration of an endogenous retrovirus (intracisternal A particle) into an intron.[9][10]
Tap protein
In molecular biology, another name for the protein NXF1 is TAP. In particular this entry focuses on the C-terminal domain, which also contains the UBA (protein domain).
This entry contains the NXF family of shuttling transport receptors for nuclear export of mRNA, which include:
- vertebrate mRNA export factor TAP or nuclear RNA export factor 1 (NXF1).
- Caenorhabditis elegans nuclear RNA export factor 1 (nxf-1).
- yeast mRNA export factor MEX67. Members of the NXF family have a modular structure. A nuclear localization sequence and a noncanonical RNA recognition motif (RRM) (see PROSITEDOC) followed by four LRR repeats are located in its N-terminal half. The C-terminal half contains a NTF2 domain (see [href="http://expasy.org/prosite/PDOC50177 PROSITEDOC]) followed by a second domain, TAP-C. The TAP-C domain is important for binding to FG repeat-containing nuclear pore proteins (FG-nucleoporins) and is sufficient to mediate nuclear shuttling.[18][19]
The Tap-C domain is made of four alpha helices packed against each other. The arrangement of helices 1, 2 and 3 is similar to that seen in a UBA fold. and is joined to the next module by flexible 12-residue Pro-rich linker.[18][19]
Function
Nuclear export of mRNAs is mediated by the Tap protein.
Structure
Tap can form a multimeric complex with itself and with other members of the NXF family. Three functional domains of Tap have been well characterized: the RNA-binding domain, the Nuclear Transport Factor 2 (NTF2)-like domain, and the ubiquitin-associated (UBA) domain.