ID ST_POVHA Reviewed; 194 AA.
AC P03080;
DT 21-JUL-1986, integrated into UniProtKB/Swiss-Prot.
DT 21-JUL-1986, sequence version 1.
DT 22-FEB-2023, entry version 95.
DE RecName: Full=Small t antigen;
DE Short=ST;
DE Short=ST-AG;
OS Hamster polyomavirus (HaPyV) (Mesocricetus auratus polyomavirus 1).
OC Viruses; Monodnaviria; Shotokuvirae; Cossaviricota; Papovaviricetes;
OC Sepolyvirales; Polyomaviridae; Alphapolyomavirus.
OX NCBI_TaxID=1891729;
OH NCBI_TaxID=10036; Mesocricetus auratus (Golden hamster).
RN [1]
RP NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RX PubMed=2988942; DOI=10.1002/j.1460-2075.1985.tb03773.x;
RA Delmas V., Bastien C., Scherneck S., Feunteun J.;
RT "A new member of the polyomavirus family: the hamster papovavirus. Complete
RT nucleotide sequence and transformation properties.";
RL EMBO J. 4:1279-1286(1985).
CC -!- FUNCTION: Promotes efficient viral genome replication by accelerating
CC both G1 and S phase progression of the cell cycle. Inhibits host PP2A
CC by binding to the A subunit, thereby displacing lower affinity
CC regulatory B subunit. Inactivation of PP2A in turn results in the
CC transactivation of cyclin A and cyclin D1 promoters. Late during the
CC infection cycle, ST may induce dephosphorylation of host MTOR, leading
CC to the inhibition of cap-dependent translation. May establish and
CC maintain high levels of viral genomes during persistent infection in
CC cell culture. {ECO:0000250|UniProtKB:P03081}.
CC -!- SUBUNIT: Interacts with host PPP2R1A; the interaction inhibits PP2A
CC activity. {ECO:0000250|UniProtKB:P03081}.
CC -!- SUBCELLULAR LOCATION: Host cytoplasm. Host nucleus
CC {ECO:0000250|UniProtKB:P03081}.
CC -!- ALTERNATIVE PRODUCTS:
CC Event=Alternative splicing; Named isoforms=3;
CC Name=Small t antigen;
CC IsoId=P03080-1; Sequence=Displayed;
CC Name=Middle T antigen;
CC IsoId=P03079-1; Sequence=External;
CC Name=Large T antigen;
CC IsoId=P03075-1; Sequence=External;
CC -!- DOMAIN: The common region of ST and LT proteins comprises the J domain.
CC This domain is essential for multiple viral activities, including
CC virion assembly, viral DNA replication, transformation and
CC transcriptional activation. This domain is also required for cyclin A-
CC transactivating activity of ST. {ECO:0000250|UniProtKB:P03081}.
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DR EMBL; M26281; AAA67116.1; -; Genomic_DNA.
DR EMBL; X02449; CAB59363.1; -; Genomic_DNA.
DR PIR; A03616; TVVPAH.
DR RefSeq; YP_009111409.1; NC_001663.2. [P03080-1]
DR SMR; P03080; -.
DR GeneID; 29030999; -.
DR KEGG; vg:29030999; -.
DR OrthoDB; 14669at10239; -.
DR Proteomes; UP000008477; Genome.
DR GO; GO:0030430; C:host cell cytoplasm; IEA:UniProtKB-SubCell.
DR GO; GO:0042025; C:host cell nucleus; IEA:UniProtKB-SubCell.
DR GO; GO:0046872; F:metal ion binding; IEA:UniProtKB-KW.
DR Gene3D; 1.10.287.110; DnaJ domain; 1.
DR Gene3D; 1.20.120.1860; Small t-antigen, unique domain; 1.
DR InterPro; IPR001623; DnaJ_domain.
DR InterPro; IPR036869; J_dom_sf.
DR InterPro; IPR003354; Papo_T_antigen.
DR InterPro; IPR036092; Papo_T_antigensf.
DR Pfam; PF02380; Papo_T_antigen; 1.
DR SMART; SM00271; DnaJ; 1.
DR SUPFAM; SSF46565; Chaperone J-domain; 1.
DR SUPFAM; SSF161240; T-antigen specific domain-like; 1.
DR PROSITE; PS50076; DNAJ_2; 1.
PE 3: Inferred from homology;
KW Acetylation; Activator; Alternative splicing; Early protein;
KW Host cytoplasm; Host nucleus; Host-virus interaction; Metal-binding;
KW Oncogene; Phosphoprotein; Reference proteome; Transcription;
KW Transcription regulation; Zinc; Zinc-finger.
FT CHAIN 1..194
FT /note="Small t antigen"
FT /id="PRO_0000115055"
FT DOMAIN 12..75
FT /note="J"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00286"
FT ZN_FING 109..123
FT /note="C4-type; atypical"
FT ZN_FING 129..151
FT /note="H1C3-type; atypical"
FT MOD_RES 1
FT /note="N-acetylmethionine; by host"
FT /evidence="ECO:0000250|UniProtKB:P03081"
SQ SEQUENCE 194 AA; 22625 MW; 9291BA085D765280 CRC64;
MDRILTKEEK QALISLLDLE PQYWGDYGRM QKCYKKKCLQ LHPDKGGNEE LMQQLNTLWT
KLKDGLYRVR LLLGPSQVRR LGKDQWNLSL QQTFSGTYFR RLCRLPITCL RNKGISTCNC
ILCLLRKQHF LLKKSWRVPC LVLGECYCID CFALWFGLPV TNMLVPLYAQ FLAPIPVDWL
DLNVHEVYNP ASGP
//
