ID   MT_POVM3                Reviewed;         421 AA.
AC   P0DOJ8; P03076; Q76TX4; Q76W01; Q89765;
DT   20-DEC-2017, integrated into UniProtKB/Swiss-Prot.
DT   20-DEC-2017, sequence version 1.
DT   03-AUG-2022, entry version 19.
DE   RecName: Full=Middle T antigen;
DE            Short=MT;
DE            Short=MT-AG;
OS   Murine polyomavirus (strain A3) (MPyV).
OC   Viruses; Monodnaviria; Shotokuvirae; Cossaviricota; Papovaviricetes;
OC   Sepolyvirales; Polyomaviridae; Alphapolyomavirus.
OX   NCBI_TaxID=157703;
OH   NCBI_TaxID=10090; Mus musculus (Mouse).
RN   [1]
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RX   PubMed=225042; DOI=10.1016/0092-8674(79)90278-2;
RA   Friedmann T., Esty A., LaPorte P., Deininger P.L.;
RT   "The nucleotide sequence and genome organization of the polyoma early
RT   region: extensive nucleotide and amino acid homology with SV40.";
RL   Cell 17:715-724(1979).
RN   [2]
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RX   PubMed=6253927;
RA   Deininger P.L., Esty A., LaPorte P., Hsu H., Friedmann T.;
RT   "The nucleotide sequence and restriction enzyme sites of the polyoma
RT   genome.";
RL   Nucleic Acids Res. 8:855-860(1980).
CC   -!- FUNCTION: Plays a role in transformation by modulating the activities
CC       of cellular proteins involved in control of cell proliferation and by
CC       acting as a functional homolog of an activated tyrosine kinase-
CC       associated growth-factor receptor. Recruits upon association with host
CC       Ppp2/PP2A the Src tyrosine kinase components Src, Yes and Fyn, thereby
CC       activating their kinase activity. Activation of Shc1, Pclg1 and p85
CC       mediate signal transduction pathways leading to cell cycle progression
CC       and cell division. MT also plays a role in regulation of early and late
CC       gene expression and in viral DNA replication.
CC       {ECO:0000250|UniProtKB:P03077}.
CC   -!- SUBUNIT: Interacts with host Ppp2/PP2A A and C subunits; this
CC       interaction alters Ppp2/PP2A substrate specificity and localization.
CC       Interacts with host Src, Yes1, and Fyn. Interacts with host Shc1, Plcg1
CC       and p85; these interactions lead to cell cycle progression. Interacts
CC       with host 14-3-3 proteins. {ECO:0000250|UniProtKB:P03077}.
CC   -!- SUBCELLULAR LOCATION: Host membrane {ECO:0000305}; Single-pass membrane
CC       protein {ECO:0000305}.
CC   -!- ALTERNATIVE PRODUCTS:
CC       Event=Alternative splicing; Named isoforms=3;
CC       Name=Middle T antigen;
CC         IsoId=P0DOJ8-1, P03076-1;
CC         Sequence=Displayed;
CC       Name=Small t antigen;
CC         IsoId=P68834-1; Sequence=External;
CC       Name=Large T antigen;
CC         IsoId=P0DOJ5-1, P03074-1;
CC         Sequence=External;
CC   -!- DOMAIN: The NPTY motif is required for interaction with host Shc1
CC       protein.
CC   -!- PTM: Tyrosine-phosphorylated on three residues 250, 315 and 322,
CC       providing docking sites for host Shc1, p85, and Plcg1, respectively.
CC       {ECO:0000250|UniProtKB:P03077}.
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DR   EMBL; J02289; AAA46873.1; -; Genomic_DNA.
DR   PIR; A93718; TVVPM.
DR   SMR; P0DOJ8; -.
DR   Proteomes; UP000006847; Genome.
DR   GO; GO:0033644; C:host cell membrane; IEA:UniProtKB-SubCell.
DR   GO; GO:0016021; C:integral component of membrane; IEA:UniProtKB-KW.
DR   Gene3D; 1.10.287.110; -; 1.
DR   Gene3D; 1.20.120.1860; -; 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; SSF161240; SSF161240; 1.
DR   SUPFAM; SSF46565; SSF46565; 1.
PE   3: Inferred from homology;
KW   Alternative splicing; Early protein; Host membrane; Host-virus interaction;
KW   Membrane; Oncogene; Phosphoprotein; Transmembrane; Transmembrane helix.
FT   CHAIN           1..421
FT                   /note="Middle T antigen"
FT                   /id="PRO_0000442784"
FT   TOPO_DOM        1..394
FT                   /note="Cytoplasmic"
FT                   /evidence="ECO:0000255"
FT   TRANSMEM        395..415
FT                   /note="Helical"
FT                   /evidence="ECO:0000255"
FT   TOPO_DOM        416..421
FT                   /note="Extracellular"
FT                   /evidence="ECO:0000255"
FT   DOMAIN          12..75
FT                   /note="J"
FT   REGION          215..237
FT                   /note="Disordered"
FT                   /evidence="ECO:0000256|SAM:MobiDB-lite"
FT   MOD_RES         250
FT                   /note="Phosphotyrosine; by host"
FT                   /evidence="ECO:0000250|UniProtKB:P03077"
FT   MOD_RES         257
FT                   /note="Phosphoserine; by host"
FT                   /evidence="ECO:0000250|UniProtKB:P03077"
FT   MOD_RES         315
FT                   /note="Phosphotyrosine; by host"
FT                   /evidence="ECO:0000250|UniProtKB:P03077"
FT   MOD_RES         322
FT                   /note="Phosphotyrosine; by host"
FT                   /evidence="ECO:0000250|UniProtKB:P03077"
SQ   SEQUENCE   421 AA;  48694 MW;  FC394691F84E8EB5 CRC64;
     MDRVLSRADK ERLLELLKLP RQLWGDFGRM QQAYKQQSLL LHPDKGGSHA LMQELNSLWG
     TFKTEVYNLR MNLGGTGFQV RRLHADGWNL STKDTFGDRY YQRFCRMPLT CLVNVKYSSC
     SCILCLLRKQ HRELKDKCDA RCLVLGECFC LECYMQWFGT PTRDVLNLYA DFIASMPIDW
     LDLDVHSVYN PKRRSEELRR AATVHYTMTT GHSAMEASTS QGNGMISSES GTPATSRRLR
     LPSLLSNPTY SVMRSHSYPP TRVLQQIHPH ILLEEDEILV LLSPMTAYPR TPPELLYPES
     DQDQLEPLEE EEEEYMPMED LYLDILPEEQ VPQLIPPPII PRAGLSPWEG LILRDLQRAH
     FDPILDASQR MRATHRAALR AHSMQRHLRR LGRTLLLVTF LAALLGICLM LFILIKRSRH
     F