TAT_SIVVT
ID TAT_SIVVT Reviewed; 100 AA.
AC P05913;
DT 01-NOV-1988, integrated into UniProtKB/Swiss-Prot.
DT 01-NOV-1988, sequence version 1.
DT 23-FEB-2022, entry version 98.
DE RecName: Full=Protein Tat;
DE AltName: Full=Transactivating regulatory protein;
GN Name=tat;
OS Simian immunodeficiency virus agm.vervet (isolate AGM TYO-1) (SIV-agm.ver)
OS (Simian immunodeficiency virus African green monkey vervet).
OC Viruses; Riboviria; Pararnavirae; Artverviricota; Revtraviricetes;
OC Ortervirales; Retroviridae; Orthoretrovirinae; Lentivirus.
OX NCBI_TaxID=11731;
OH NCBI_TaxID=9527; Cercopithecidae (Old World monkeys).
RN [1]
RP NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RX PubMed=3374586; DOI=10.1038/333457a0;
RA Fukasawa M., Miura T., Hasegawa A., Morikawa S., Tsujimoto H., Miki K.,
RA Kitamura T., Hayami M.;
RT "Sequence of simian immunodeficiency virus from African green monkey, a new
RT member of the HIV/SIV group.";
RL Nature 333:457-461(1988).
CC -!- FUNCTION: Nuclear transcriptional activator of viral gene expression,
CC that is essential for viral transcription from the LTR promoter and
CC replication. Acts as a sequence-specific molecular adapter, directing
CC components of the cellular transcription machinery to the viral RNA to
CC promote processive transcription elongation by the RNA polymerase II
CC (RNA pol II) complex, thereby increasing the level of full-length
CC transcripts. In the absence of Tat, the RNA Pol II generates short or
CC non-processive transcripts that terminate at approximately 60 bp from
CC the initiation site. Tat associates with the CCNT1/cyclin-T1 component
CC of the P-TEFb complex (CDK9 and CCNT1), which promotes RNA chain
CC elongation. This binding increases Tat's affinity for a hairpin
CC structure at the 5'-end of all nascent viral mRNAs referred to as the
CC transactivation responsive RNA element (TAR RNA) and allows Tat/P-TEFb
CC complex to bind cooperatively to TAR RNA. The CDK9 component of P-TEFb
CC and other Tat-activated kinases hyperphosphorylate the C-terminus of
CC RNA Pol II that becomes stabilized and much more processive (By
CC similarity). {ECO:0000250}.
CC -!- FUNCTION: Extracellular circulating Tat can be endocytosed by
CC surrounding uninfected cells via the binding to several surface
CC receptors. Endosomal low pH allows Tat to cross the endosome membrane
CC to enter the cytosol and eventually further translocate into the
CC nucleus, thereby inducing severe cell dysfunctions ranging from cell
CC activation to cell death. Through (By similarity). {ECO:0000250}.
CC -!- SUBUNIT: Interacts with host CCNT1. Associates with the P-TEFb complex
CC composed at least of Tat, P-TEFb (CDK9 and CCNT1), TAR RNA, RNA Pol II.
CC Interacts with CCNT2; the resulting complex is unable to bind to TAR
CC RNA (By similarity). {ECO:0000250}.
CC -!- SUBCELLULAR LOCATION: Host nucleus, host nucleolus {ECO:0000250}.
CC -!- SIMILARITY: Belongs to the lentiviruses Tat family. {ECO:0000305}.
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DR EMBL; X07805; CAA30661.1; -; Genomic_DNA.
DR GO; GO:0044196; C:host cell nucleolus; IEA:UniProtKB-SubCell.
DR GO; GO:0003723; F:RNA binding; IEA:UniProtKB-KW.
DR GO; GO:0001070; F:RNA-binding transcription regulator activity; IEA:InterPro.
DR GO; GO:0050434; P:positive regulation of viral transcription; IEA:InterPro.
DR Gene3D; 4.10.20.10; -; 1.
DR InterPro; IPR001831; IV_Tat.
DR InterPro; IPR036963; Tat_dom_sf.
DR Pfam; PF00539; Tat; 1.
DR PRINTS; PR00055; HIVTATDOMAIN.
PE 3: Inferred from homology;
KW Activator; Host nucleus; Host-virus interaction; RNA-binding;
KW Transcription; Transcription regulation.
FT CHAIN 1..100
FT /note="Protein Tat"
FT /id="PRO_0000085380"
FT REGION 26..42
FT /note="Cysteine-rich"
FT /evidence="ECO:0000250"
FT REGION 43..53
FT /note="Core"
FT /evidence="ECO:0000250"
FT REGION 76..100
FT /note="Disordered"
FT /evidence="ECO:0000256|SAM:MobiDB-lite"
FT MOTIF 54..60
FT /note="Nuclear localization signal, and RNA-binding (TAR)"
FT /evidence="ECO:0000255"
SQ SEQUENCE 100 AA; 11387 MW; 5B77B7AEA8823C9E CRC64;
MDKGEAEQIV SHQDLSEDYQ KPLQTCKNKC FCKKCCYHCQ LCFLQKGLGV TYHAPRTRRK
KIRSLNLAPL QHQSISTKWG RDGQTTPTSQ EKVETTAGSN