P0C206 · REX_HTL1C
- ProteinProtein Rex
- StatusUniProtKB reviewed (Swiss-Prot)
- Amino acids189 (go to sequence)
- Protein existenceEvidence at protein level
- Annotation score5/5
Function
function
Rex escorts unspliced gag-pro-pol and singly spliced env mRNAs out of the nucleus of infected cells. These mRNAs carry a recognition sequence called Rex responsive element (RxRE or XRE) located at the 3' region of the long terminal repeat (LTR). This function is essential since most HTLV proteins are translated from unspliced or partially spliced pre-mRNAs that cannot exit the nucleus by the pathway used by fully processed cellular mRNAs. Rex itself is translated from a fully spliced mRNA that probably readily exits the nucleus. Rex's nuclear localization signal (NLS) binds directly to KPNB1/importin beta-1 without previous binding to KPNA1/importin alpha-1. KPNB1 binds to the GDP bound form of RAN (Ran-GDP) and targets Rex to the nucleus. In the nucleus, the conversion from Ran-GDP to Ran-GTP dissociates Rex from KPNB1 and allows Rex's binding to the RRE in viral pre-mRNAs. Rex multimerizes on the RRE via cooperative assembly. This multimerization is critical for its full biological activity, since it may shield the viral RNA from being spliced or down-regulated, and probably exposes Rex's nuclear export signal (NES) to the surface. Rex can then form a complex with XPO1/CRM1, RANBP3 and Ran-GTP, leading to nuclear export of the complex. Conversion from Ran-GTP to Ran-GDP mediates dissociation of the Rex/RRE/XPO1/RANBP3/RAN complex, so that Rex can return to the nucleus for a subsequent round of export (By similarity).
Miscellaneous
HTLV-1 lineages are divided in four clades, A (Cosmopolitan), B (Central African group), C (Melanesian group) and D (New Central African group).
GO annotations
Aspect | Term | |
---|---|---|
Cellular Component | host cell cytoplasm | |
Cellular Component | host cell nucleolus | |
Molecular Function | RNA binding | |
Biological Process | mRNA transport |
Keywords
- Molecular function
- Biological process
Names & Taxonomy
Protein names
- Recommended nameProtein Rex
- Alternative names
Organism names
- Taxonomic lineageViruses > Riboviria > Pararnavirae > Artverviricota > Revtraviricetes > Ortervirales > Retroviridae > Orthoretrovirinae > Deltaretrovirus > Primate T-lymphotropic virus 1
- Virus hosts
Accessions
- Primary accessionP0C206
- Secondary accessions
Proteomes
Subcellular Location
UniProt Annotation
GO Annotation
Isoform Rex
Note: The presence of both nuclear import and nuclear export signals leads to continuous shuttling between the nucleus and cytoplasm.
Isoform p21Rex
Keywords
- Cellular component
PTM/Processing
Features
Showing features for chain, modified residue.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Chain | PRO_0000259783 | 1-189 | Protein Rex | |||
Sequence: MPKTRRRPRRSQRKRPPTPWPTSQGLDRVFFSDTQSTCLETVYKATGAPSLGDYVRPAYIVTPYWPPVQSIRSPGTPSMDALSAQLYSSLSLDSPPSPPREPLRPLRSLPRQSLIQPPTFHPPSSRPCANTPPSEMDTWNPPLGSTSQPCLFQTPDSGPKTCTPSGEAPLSACTSTSFPPPSPGPSCPM | ||||||
Modified residue | 70 | Phosphoserine; by host | ||||
Sequence: S | ||||||
Modified residue | 174 | Phosphothreonine; by host | ||||
Sequence: T | ||||||
Modified residue | 177 | Phosphoserine; by host | ||||
Sequence: S |
Post-translational modification
Phosphorylated.
Keywords
- PTM
PTM databases
Expression
Induction
Down-regulated by P30II.
Interaction
Subunit
Homomultimer. Multimeric assembly is essential for activity and involves XPO1. Binds to human XPO1 and KPNB1 (By similarity).
Interacts (via N-terminal nuclear localization signal) with human NPM1
Interacts (via N-terminal nuclear localization signal) with human NPM1
Binary interactions
Type | Entry 1 | Entry 2 | Number of experiments | Intact | |
---|---|---|---|---|---|
XENO | P0C206 | BHLHE40 O14503 | 3 | EBI-9675596, EBI-711810 | |
XENO | P0C206 | DYNLL2 Q96FJ2 | 4 | EBI-9675596, EBI-742371 | |
XENO | P0C206 | LNX2 Q8N448 | 4 | EBI-9675596, EBI-2340947 | |
XENO | P0C206 | LZTS2 Q9BRK4 | 4 | EBI-9675596, EBI-741037 | |
XENO | P0C206 | TTC23L Q6PF05 | 3 | EBI-9675596, EBI-8656864 |
Protein-protein interaction databases
Structure
Family & Domains
Features
Showing features for region, motif, compositional bias.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Region | 1-27 | Disordered | ||||
Sequence: MPKTRRRPRRSQRKRPPTPWPTSQGLD | ||||||
Motif | 2-18 | Nuclear localization signal, and RNA-binding (RxRE) | ||||
Sequence: PKTRRRPRRSQRKRPPT | ||||||
Region | 56-70 | Homomultimerization | ||||
Sequence: RPAYIVTPYWPPVQS | ||||||
Motif | 82-93 | Nuclear export signal | ||||
Sequence: LSAQLYSSLSLD | ||||||
Region | 87-189 | Disordered | ||||
Sequence: YSSLSLDSPPSPPREPLRPLRSLPRQSLIQPPTFHPPSSRPCANTPPSEMDTWNPPLGSTSQPCLFQTPDSGPKTCTPSGEAPLSACTSTSFPPPSPGPSCPM | ||||||
Region | 123-131 | Homomultimerization | ||||
Sequence: PSSRPCANT | ||||||
Compositional bias | 130-161 | Polar residues | ||||
Sequence: NTPPSEMDTWNPPLGSTSQPCLFQTPDSGPKT |
Domain
The RNA-binding motif binds to the RxRE, a complex secondary structure consisting of four stem loops and a long stretch of stem structure, present in incompletely spliced viral pre-mRNAs. This region also contains the NLS which mediates nuclear localization. These overlapping functions prevent Rex bound to RxRE from undesirable return to the nucleus. When Rex binds the RxRE, the NLS becomes masked while the NES remains accessible. The leucine-rich NES mediates binding to human XPO1 (By similarity).
Sequence similarities
Belongs to the deltaretrovirus Rex protein family.
Family and domain databases
Sequence & Isoform
- Sequence statusComplete
This entry describes 2 isoforms produced by Alternative splicing.
P0C206-1
This isoform has been chosen as the canonical sequence. All positional information in this entry refers to it. This is also the sequence that appears in the downloadable versions of the entry.
- NameRex
- Synonymsp27Rex
- Length189
- Mass (Da)20,555
- Last updated2006-11-14 v1
- ChecksumD47A22D76F7A2449
P0C206-2
- Namep21Rex
- Synonymsp21
- Differences from canonical
- 1-78: Missing
Sequence caution
Features
Showing features for alternative sequence, compositional bias.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Alternative sequence | VSP_021540 | 1-78 | in isoform p21Rex | |||
Sequence: Missing | ||||||
Compositional bias | 130-161 | Polar residues | ||||
Sequence: NTPPSEMDTWNPPLGSTSQPCLFQTPDSGPKT |
Keywords
- Coding sequence diversity
- Technical term
Sequence databases
Nucleotide Sequence | Protein Sequence | Molecule Type | Status | |
---|---|---|---|---|
D13784 EMBL· GenBank· DDBJ | - | Genomic DNA | No translation available. | |
AF033817 EMBL· GenBank· DDBJ | AAC82584.1 EMBL· GenBank· DDBJ | Genomic DNA | Sequence problems. |