ID   REX_HTL32               Reviewed;         182 AA.
AC   Q0R5R0;
DT   14-NOV-2006, integrated into UniProtKB/Swiss-Prot.
DT   14-NOV-2006, sequence version 2.
DT   02-JUN-2021, entry version 35.
DE   RecName: Full=Protein Rex;
DE   AltName: Full=Rev homolog;
DE   AltName: Full=Rex-3;
GN   Name=rex;
OS   Human T-cell leukemia virus 3 (strain 2026ND) (HTLV-3).
OC   Viruses; Riboviria; Pararnavirae; Artverviricota; Revtraviricetes;
OC   Ortervirales; Retroviridae; Orthoretrovirinae; Deltaretrovirus.
OX   NCBI_TaxID=402036;
OH   NCBI_TaxID=9606; Homo sapiens (Human).
RN   [1]
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RX   PubMed=16840323; DOI=10.1128/jvi.00690-06;
RA   Switzer W.M., Qari S.H., Wolfe N.D., Burke D.S., Folks T.M., Heneine W.;
RT   "Ancient origin and molecular features of the novel human T-lymphotropic
RT   virus type 3 revealed by complete genome analysis.";
RL   J. Virol. 80:7427-7438(2006).
CC   -!- FUNCTION: Rex escorts unspliced gag-pro-pol and singly spliced env
CC       mRNAs out of the nucleus of infected cells. These mRNAs carry a
CC       recognition sequence called Rex responsive element (RxRE or XRE)
CC       located at the 3' region of the long terminal repeat (LTR). This
CC       function is essential since most HTLV proteins are translated from
CC       unspliced or partially spliced pre-mRNAs that cannot exit the nucleus
CC       by the pathway used by fully processed cellular mRNAs (By similarity).
CC       {ECO:0000250}.
CC   -!- SUBUNIT: Homomultimer. {ECO:0000250}.
CC   -!- SUBCELLULAR LOCATION: Host nucleus, host nucleolus {ECO:0000250}. Host
CC       cytoplasm {ECO:0000250}. Note=The presence of both nuclear import (NLS)
CC       and nuclear export (NES) signals leads to continuous shuttling between
CC       the nucleus and cytoplasm. {ECO:0000250}.
CC   -!- DOMAIN: The RNA-binding motif binds to the RxRE, a complex secondary
CC       structure consisting of four stem loops and a long stretch of stem
CC       structure, present in incompletely spliced viral pre-mRNAs. This region
CC       also contains the NLS which mediates nuclear localization. These
CC       overlapping functions prevent Rex bound to RxRE from undesirable return
CC       to the nucleus. When Rex binds the RxRE, the NLS becomes masked while
CC       the NES remains accessible (By similarity). {ECO:0000250}.
CC   -!- SIMILARITY: Belongs to the deltaretrovirus Rex protein family.
CC       {ECO:0000305}.
CC   -!- SEQUENCE CAUTION:
CC       Sequence=AAZ77660.1; Type=Erroneous gene model prediction; Evidence={ECO:0000305};
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DR   EMBL; DQ093792; AAZ77660.1; ALT_SEQ; Genomic_DNA.
DR   PRIDE; Q0R5R0; -.
DR   Proteomes; UP000008029; Genome.
DR   GO; GO:0030430; C:host cell cytoplasm; IEA:UniProtKB-SubCell.
DR   GO; GO:0044196; C:host cell nucleolus; IEA:UniProtKB-SubCell.
DR   GO; GO:0003723; F:RNA binding; IEA:UniProtKB-KW.
DR   GO; GO:0051028; P:mRNA transport; IEA:UniProtKB-KW.
PE   3: Inferred from homology;
KW   Host cytoplasm; Host nucleus; mRNA transport; Reference proteome;
KW   RNA-binding; Transport.
FT   CHAIN           1..182
FT                   /note="Protein Rex"
FT                   /id="PRO_0000259787"
FT   REGION          1..26
FT                   /note="Disordered"
FT                   /evidence="ECO:0000256|SAM:MobiDB-lite"
FT   REGION          57..71
FT                   /note="Homomultimerization"
FT                   /evidence="ECO:0000250"
FT   REGION          89..169
FT                   /note="Disordered"
FT                   /evidence="ECO:0000256|SAM:MobiDB-lite"
FT   REGION          124..132
FT                   /note="Homomultimerization"
FT                   /evidence="ECO:0000250"
FT   MOTIF           2..19
FT                   /note="Nuclear localization signal, and RNA-binding (RxRE)"
FT                   /evidence="ECO:0000250"
FT   MOTIF           83..94
FT                   /note="Nuclear export signal"
FT                   /evidence="ECO:0000250"
FT   COMPBIAS        97..121
FT                   /note="Pro residues"
FT                   /evidence="ECO:0000256|SAM:MobiDB-lite"
FT   COMPBIAS        125..162
FT                   /note="Polar residues"
FT                   /evidence="ECO:0000256|SAM:MobiDB-lite"
SQ   SEQUENCE   182 AA;  19674 MW;  36DBA48A68693CEC CRC64;
     MPKTRKQRSR RPKNQRPSTP WPISQVSDRA FSTGTLSTFS ATVYRPIGAP FLGGFVPLGY
     TAMPYWPRAP NIRLPGTPSM DALSAQLYNT LSLDSPPSPP RELPAPSRFS PPQPLLRPPR
     FLHPSSTPLK NTPPSETIAL NSPWESSCQP CPSPTLGSDP KTSTPCGEAP LCAFTSISSP
     PP