ID CD4_HUMAN Reviewed; 458 AA. AC P01730; B2R737; D3DUS5; Q4ZGK2; Q5U066; Q9UDE5; DT 21-JUL-1986, integrated into UniProtKB/Swiss-Prot. DT 01-NOV-1988, sequence version 1. DT 13-FEB-2019, entry version 220. DE RecName: Full=T-cell surface glycoprotein CD4; DE AltName: Full=T-cell surface antigen T4/Leu-3; DE AltName: CD_antigen=CD4; DE Flags: Precursor; GN Name=CD4; OS Homo sapiens (Human). OC Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi; OC Mammalia; Eutheria; Euarchontoglires; Primates; Haplorrhini; OC Catarrhini; Hominidae; Homo. OX NCBI_TaxID=9606; RN [1] RP NUCLEOTIDE SEQUENCE [MRNA], AND SUBCELLULAR LOCATION. RX PubMed=2990730; DOI=10.1016/S0092-8674(85)80105-7; RA Maddon P.J., Littman D.R., Godfrey M., Maddon D.E., Chess L., Axel R.; RT "The isolation and nucleotide sequence of a cDNA encoding the T cell RT surface protein T4: a new member of the immunoglobulin gene family."; RL Cell 42:93-104(1985). RN [2] RP SEQUENCE REVISION TO 26. RX PubMed=3263213; DOI=10.1016/0092-8674(88)90211-5; RA Littman D.R., Maddon P.J., Axel R.; RT "Corrected CD4 sequence."; RL Cell 55:541-541(1988). RN [3] RP NUCLEOTIDE SEQUENCE [GENOMIC DNA]. RX PubMed=8723724; DOI=10.1101/gr.6.4.314; RA Ansari-Lari M.A., Muzny D.M., Lu J., Lu F., Lilley C.E., Spanos S., RA Malley T., Gibbs R.A.; RT "A gene-rich cluster between the CD4 and triosephosphate isomerase RT genes at human chromosome 12p13."; RL Genome Res. 6:314-326(1996). RN [4] RP NUCLEOTIDE SEQUENCE [GENOMIC DNA]. RC TISSUE=Brain; RX PubMed=9074930; DOI=10.1101/gr.7.3.268; RA Ansari-Lari M.A., Shen Y., Muzny D.M., Lee W., Gibbs R.A.; RT "Large-scale sequencing in human chromosome 12p13: experimental and RT computational gene structure determination."; RL Genome Res. 7:268-280(1997). RN [5] RP NUCLEOTIDE SEQUENCE [MRNA], POLYMORPHISM, VARIANT TRP-265, AND RP TOPOLOGY. RX PubMed=1708753; DOI=10.1016/0198-8859(91)90077-M; RA Hodge T.W., Sasso D.R., McDougal J.S.; RT "Humans with OKT4-epitope deficiency have a single nucleotide base RT change in the CD4 gene, resulting in substitution of TRP240 for RT ARG240."; RL Hum. Immunol. 30:99-104(1991). RN [6] RP NUCLEOTIDE SEQUENCE [LARGE SCALE MRNA]. RA Kalnine N., Chen X., Rolfs A., Halleck A., Hines L., Eisenstein S., RA Koundinya M., Raphael J., Moreira D., Kelley T., LaBaer J., Lin Y., RA Phelan M., Farmer A.; RT "Cloning of human full-length CDSs in BD Creator(TM) system donor RT vector."; RL Submitted (MAY-2003) to the EMBL/GenBank/DDBJ databases. RN [7] RP NUCLEOTIDE SEQUENCE [LARGE SCALE MRNA]. RC TISSUE=Thymus; RX PubMed=14702039; DOI=10.1038/ng1285; RA Ota T., Suzuki Y., Nishikawa T., Otsuki T., Sugiyama T., Irie R., RA Wakamatsu A., Hayashi K., Sato H., Nagai K., Kimura K., Makita H., RA Sekine M., Obayashi M., Nishi T., Shibahara T., Tanaka T., Ishii S., RA Yamamoto J., Saito K., Kawai Y., Isono Y., Nakamura Y., Nagahari K., RA Murakami K., Yasuda T., Iwayanagi T., Wagatsuma M., Shiratori A., RA Sudo H., Hosoiri T., Kaku Y., Kodaira H., Kondo H., Sugawara M., RA Takahashi M., Kanda K., Yokoi T., Furuya T., Kikkawa E., Omura Y., RA Abe K., Kamihara K., Katsuta N., Sato K., Tanikawa M., Yamazaki M., RA Ninomiya K., Ishibashi T., Yamashita H., Murakawa K., Fujimori K., RA Tanai H., Kimata M., Watanabe M., Hiraoka S., Chiba Y., Ishida S., RA Ono Y., Takiguchi S., Watanabe S., Yosida M., Hotuta T., Kusano J., RA Kanehori K., Takahashi-Fujii A., Hara H., Tanase T.-O., Nomura Y., RA Togiya S., Komai F., Hara R., Takeuchi K., Arita M., Imose N., RA Musashino K., Yuuki H., Oshima A., Sasaki N., Aotsuka S., RA Yoshikawa Y., Matsunawa H., Ichihara T., Shiohata N., Sano S., RA Moriya S., Momiyama H., Satoh N., Takami S., Terashima Y., Suzuki O., RA Nakagawa S., Senoh A., Mizoguchi H., Goto Y., Shimizu F., Wakebe H., RA Hishigaki H., Watanabe T., Sugiyama A., Takemoto M., Kawakami B., RA Yamazaki M., Watanabe K., Kumagai A., Itakura S., Fukuzumi Y., RA Fujimori Y., Komiyama M., Tashiro H., Tanigami A., Fujiwara T., RA Ono T., Yamada K., Fujii Y., Ozaki K., Hirao M., Ohmori Y., RA Kawabata A., Hikiji T., Kobatake N., Inagaki H., Ikema Y., Okamoto S., RA Okitani R., Kawakami T., Noguchi S., Itoh T., Shigeta K., Senba T., RA Matsumura K., Nakajima Y., Mizuno T., Morinaga M., Sasaki M., RA Togashi T., Oyama M., Hata H., Watanabe M., Komatsu T., RA Mizushima-Sugano J., Satoh T., Shirai Y., Takahashi Y., Nakagawa K., RA Okumura K., Nagase T., Nomura N., Kikuchi H., Masuho Y., Yamashita R., RA Nakai K., Yada T., Nakamura Y., Ohara O., Isogai T., Sugano S.; RT "Complete sequencing and characterization of 21,243 full-length human RT cDNAs."; RL Nat. Genet. 36:40-45(2004). RN [8] RP NUCLEOTIDE SEQUENCE [GENOMIC DNA], AND VARIANTS GLU-191; SER-227 AND RP TRP-265. RG NIEHS SNPs program; RL Submitted (APR-2005) to the EMBL/GenBank/DDBJ databases. RN [9] RP NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA]. RA Mural R.J., Istrail S., Sutton G.G., Florea L., Halpern A.L., RA Mobarry C.M., Lippert R., Walenz B., Shatkay H., Dew I., Miller J.R., RA Flanigan M.J., Edwards N.J., Bolanos R., Fasulo D., Halldorsson B.V., RA Hannenhalli S., Turner R., Yooseph S., Lu F., Nusskern D.R., RA Shue B.C., Zheng X.H., Zhong F., Delcher A.L., Huson D.H., RA Kravitz S.A., Mouchard L., Reinert K., Remington K.A., Clark A.G., RA Waterman M.S., Eichler E.E., Adams M.D., Hunkapiller M.W., Myers E.W., RA Venter J.C.; RL Submitted (SEP-2005) to the EMBL/GenBank/DDBJ databases. RN [10] RP NUCLEOTIDE SEQUENCE [LARGE SCALE MRNA]. RC TISSUE=Pancreas; RX PubMed=15489334; DOI=10.1101/gr.2596504; RG The MGC Project Team; RT "The status, quality, and expansion of the NIH full-length cDNA RT project: the Mammalian Gene Collection (MGC)."; RL Genome Res. 14:2121-2127(2004). RN [11] RP NUCLEOTIDE SEQUENCE [MRNA] OF 28-424. RC TISSUE=Blood; RX PubMed=1425921; DOI=10.1002/eji.1830221132; RA Fomsgaard A., Hirsch V.M., Johnson P.R.; RT "Cloning and sequences of primate CD4 molecules: diversity of the RT cellular receptor for simian immunodeficiency virus/human RT immunodeficiency virus."; RL Eur. J. Immunol. 22:2973-2981(1992). RN [12] RP FUNCTION, AND SUBCELLULAR LOCATION. RX PubMed=2823150; DOI=10.1038/330256a0; RA Doyle C., Strominger J.L.; RT "Interaction between CD4 and class II MHC molecules mediates cell RT adhesion."; RL Nature 330:256-259(1987). RN [13] RP PHOSPHORYLATION. RX PubMed=2512251; RA DiSanto J.P., Klein J.S., Flomenberg N.; RT "Phosphorylation and down-regulation of CD4 and CD8 in human CTLs and RT mouse L cells."; RL Immunogenetics 30:494-501(1989). RN [14] RP IDENTIFICATION BY MASS SPECTROMETRY, DISULFIDE BOND, AND GLYCOSYLATION RP AT ASN-296 AND ASN-325. RX PubMed=2592374; RA Carr S.A., Hemling M.E., Folena-Wasserman G., Sweet R.W., Anumula K., RA Barr J.R., Huddleston M.J., Taylor P.; RT "Protein and carbohydrate structural analysis of a recombinant soluble RT CD4 receptor by mass spectrometry."; RL J. Biol. Chem. 264:21286-21295(1989). RN [15] RP PROTEIN SEQUENCE OF 26-40, AND TOPOLOGY. RX PubMed=15340161; DOI=10.1110/ps.04682504; RA Zhang Z., Henzel W.J.; RT "Signal peptide prediction based on analysis of experimentally RT verified cleavage sites."; RL Protein Sci. 13:2819-2824(2004). RN [16] RP NUCLEOTIDE SEQUENCE [MRNA] OF 250-280, POLYMORPHISM, AND VARIANT RP TRP-265. RX PubMed=1961196; DOI=10.1016/0161-5890(91)90003-3; RA Lederman S., DeMartino J.A., Daugherty B.L., Foeldvari I., RA Yellin M.J., Cleary A.M., Berkowitz N., Lowy I., Braunstein N.S., RA Mark G.E.; RT "A single amino acid substitution in a common African allele of the RT CD4 molecule ablates binding of the monoclonal antibody, OKT4."; RL Mol. Immunol. 28:1171-1181(1991). RN [17] RP PHOSPHORYLATION AT SER-433; SER-440 AND SER-456, AND MUTAGENESIS OF RP SER-433. RX PubMed=2105883; RA Shin J., Doyle C., Yang Z., Kappes D., Strominger J.L.; RT "Structural features of the cytoplasmic region of CD4 required for RT internalization."; RL EMBO J. 9:425-434(1990). RN [18] RP FUNCTION (MICROBIAL INFECTION), INTERACTION WITH HIV-1 ENVELOPE RP POLYPROTEIN GP160 (MICROBIAL INFECTION), AND SUBCELLULAR LOCATION RP (MICROBIAL INFECTION). RX PubMed=2214026; RA Crise B., Buonocore L., Rose J.K.; RT "CD4 is retained in the endoplasmic reticulum by the human RT immunodeficiency virus type 1 glycoprotein precursor."; RL J. Virol. 64:5585-5593(1990). RN [19] RP GLYCOSYLATION AT ASN-296 AND ASN-325. RX PubMed=2001369; DOI=10.1021/bi00223a015; RA Spellman M.W., Leonard C.K., Basa L.J., Gelineo I., van Halbeek H.; RT "Carbohydrate structures of recombinant soluble human CD4 expressed in RT Chinese hamster ovary cells."; RL Biochemistry 30:2395-2406(1991). RN [20] RP INTERACTION WITH IL16. RX PubMed=1673145; RA Cruikshank W.W., Greenstein J.L., Theodore A.C., Center D.M.; RT "Lymphocyte chemoattractant factor induces CD4-dependent RT intracytoplasmic signaling in lymphocytes."; RL J. Immunol. 146:2928-2934(1991). RN [21] RP PALMITOYLATION AT CYS-419 AND CYS-422. RX PubMed=1618861; RA Crise B., Rose J.K.; RT "Identification of palmitoylation sites on CD4, the human RT immunodeficiency virus receptor."; RL J. Biol. Chem. 267:13593-13597(1992). RN [22] RP SUBCELLULAR LOCATION (MICROBIAL INFECTION) AND MUTAGENESIS OF MET-432; RP SER-433; 438-LEU-LEU-439 AND SER-440. RX PubMed=8124721; DOI=10.1016/0092-8674(94)90360-3; RA Aiken C., Konner J., Landau N.R., Lenburg M.E., Trono D.; RT "Nef induces CD4 endocytosis: requirement for a critical dileucine RT motif in the membrane-proximal CD4 cytoplasmic domain."; RL Cell 76:853-864(1994). RN [23] RP TISSUE SPECIFICITY. RX PubMed=8088877; RA Winkel K., Sotzik F., Vremec D., Cameron P.U., Shortman K.; RT "CD4 and CD8 expression by human and mouse thymic dendritic cells."; RL Immunol. Lett. 40:93-99(1994). RN [24] RP FUNCTION (MICROBIAL INFECTION), AND INTERACTION WITH HUMAN HERPESVIRUS RP 7 SURFACE PROTEINS. RX PubMed=7909607; DOI=10.1073/pnas.91.9.3872; RA Lusso P., Secchiero P., Crowley R.W., Garzino-Demo A., Berneman Z.N., RA Gallo R.C.; RT "CD4 is a critical component of the receptor for human herpesvirus 7: RT interference with human immunodeficiency virus."; RL Proc. Natl. Acad. Sci. U.S.A. 91:3872-3876(1994). RN [25] RP INTERACTION WITH SPG21, AND MUTAGENESIS OF 457-PRO-ILE-458. RX PubMed=11113139; DOI=10.1074/jbc.M009270200; RA Zeitlmann L., Sirim P., Kremmer E., Kolanus W.; RT "Cloning of ACP33 as a novel intracellular ligand of CD4."; RL J. Biol. Chem. 276:9123-9132(2001). RN [26] RP FUNCTION (MICROBIAL INFECTION), SUBUNIT, AND SUBCELLULAR LOCATION. RX PubMed=12089508; DOI=10.1038/ni815; RA Matthias L.J., Yam P.T., Jiang X.M., Vandegraaff N., Li P., RA Poumbourios P., Donoghue N., Hogg P.J.; RT "Disulfide exchange in domain 2 of CD4 is required for entry of HIV- RT 1."; RL Nat. Immunol. 3:727-732(2002). RN [27] RP SUBCELLULAR LOCATION, INTERACTION WITH LCK, AND TOPOLOGY. RX PubMed=12517957; DOI=10.4049/jimmunol.170.2.913; RA Fragoso R., Ren D., Zhang X., Su M.W., Burakoff S.J., Jin Y.J.; RT "Lipid raft distribution of CD4 depends on its palmitoylation and RT association with Lck, and evidence for CD4-induced lipid raft RT aggregation as an additional mechanism to enhance CD3 signaling."; RL J. Immunol. 170:913-921(2003). RN [28] RP FUNCTION (MICROBIAL INFECTION), AND INTERACTION WITH HIV-1 SURFACE RP PROTEIN GP120 (MICROBIAL INFECTION). RX PubMed=16331979; DOI=10.1021/bi051120s; RA Sharma D., Balamurali M.M., Chakraborty K., Kumaran S., Jeganathan S., RA Rashid U., Ingallinella P., Varadarajan R.; RT "Protein minimization of the gp120 binding region of human CD4."; RL Biochemistry 44:16192-16202(2005). RN [29] RP INTERACTION WITH LCK. RX PubMed=16888650; DOI=10.1038/sj.embor.7400775; RA Loewenberg M., Verhaar A.P., Bilderbeek J., Marle J.V., Buttgereit F., RA Peppelenbosch M.P., van Deventer S.J., Hommes D.W.; RT "Glucocorticoids cause rapid dissociation of a T-cell-receptor- RT associated protein complex containing LCK and FYN."; RL EMBO Rep. 7:1023-1029(2006). RN [30] RP FUNCTION, AND TISSUE SPECIFICITY. RX PubMed=16951326; RA Bernstein H.B., Plasterer M.C., Schiff S.E., Kitchen C.M., Kitchen S., RA Zack J.A.; RT "CD4 expression on activated NK cells: ligation of CD4 induces RT cytokine expression and cell migration."; RL J. Immunol. 177:3669-3676(2006). RN [31] RP FUNCTION (MICROBIAL INFECTION), AND REVIEW. RX PubMed=17346169; DOI=10.2174/156652407780059177; RA Lindwasser O.W., Chaudhuri R., Bonifacino J.S.; RT "Mechanisms of CD4 downregulation by the Nef and Vpu proteins of RT primate immunodeficiency viruses."; RL Curr. Mol. Med. 7:171-184(2007). RN [32] RP GLYCOSYLATION [LARGE SCALE ANALYSIS] AT ASN-296. RC TISSUE=Liver; RX PubMed=19159218; DOI=10.1021/pr8008012; RA Chen R., Jiang X., Sun D., Han G., Wang F., Ye M., Wang L., Zou H.; RT "Glycoproteomics analysis of human liver tissue by combination of RT multiple enzyme digestion and hydrazide chemistry."; RL J. Proteome Res. 8:651-661(2009). RN [33] RP REVIEW ON FUNCTION. RX PubMed=24696433; DOI=10.1128/CMR.00097-13; RA Tubo N.J., Jenkins M.K.; RT "CD4+ T Cells: guardians of the phagosome."; RL Clin. Microbiol. Rev. 27:200-213(2014). RN [34] RP FUNCTION, AND TISSUE SPECIFICITY. RX PubMed=24942581; DOI=10.1128/JVI.00616-14; RA Zhen A., Krutzik S.R., Levin B.R., Kasparian S., Zack J.A., RA Kitchen S.G.; RT "CD4 ligation on human blood monocytes triggers macrophage RT differentiation and enhances HIV infection."; RL J. Virol. 88:9934-9946(2014). RN [35] RP X-RAY CRYSTALLOGRAPHY (2.4 ANGSTROMS) OF 26-208. RX PubMed=1701030; DOI=10.1038/348411a0; RA Wang J., Yan Y., Garrett T.P., Liu J., Rodgers D.W., Garlick R.L., RA Tarr G.E., Husain Y., Reinherz E.L., Harrison S.C.; RT "Atomic structure of a fragment of human CD4 containing two RT immunoglobulin-like domains."; RL Nature 348:411-418(1990). RN [36] RP X-RAY CRYSTALLOGRAPHY (2.3 ANGSTROMS) OF 26-208. RX PubMed=2247146; DOI=10.1038/348419a0; RA Ryu S.-E., Kwong P.D., Truneh A., Porter T.G., Arthos J., RA Rosenberg M., Dai X., Xuong N.-H., Axel R., Sweet R.W., RA Hendrickson W.A.; RT "Crystal structure of an HIV-binding recombinant fragment of human RT CD4."; RL Nature 348:419-426(1990). RN [37] RP X-RAY CRYSTALLOGRAPHY (3.9 ANGSTROMS) OF 26-388, HOMODIMERIZATION, RP INTERACTION WITH CD81, SUBCELLULAR LOCATION, AND MUTAGENESIS OF RP CYS-445 AND CYS-447. RX PubMed=9168119; DOI=10.1038/387527a0; RA Wu H., Kwong P.D., Hendrickson W.A.; RT "Dimeric association and segmental variability in the structure of RT human CD4."; RL Nature 387:527-530(1997). RN [38] RP X-RAY CRYSTALLOGRAPHY (2.5 ANGSTROMS) OF 26-208 IN COMPLEX WITH HIV RP SURFACE PROTEIN GP120 (MICROBIAL INFECTION), AND FUNCTION (MICROBIAL RP INFECTION). RX PubMed=9641677; DOI=10.1038/31405; RA Kwong P.D., Wyatt R., Robinson J., Sweet R.W., Sodroski J., RA Hendrickson W.A.; RT "Structure of an HIV gp120 envelope glycoprotein in complex with the RT CD4 receptor and a neutralizing human antibody."; RL Nature 393:648-659(1998). RN [39] RP X-RAY CRYSTALLOGRAPHY (2.82 ANGSTROMS) OF 428-450 IN COMPLEX WITH RP PTK2/FAK1, AND INTERACTION WITH PTK2/FAK1. RX PubMed=18078954; DOI=10.1016/j.jmb.2007.11.040; RA Garron M.L., Arthos J., Guichou J.F., McNally J., Cicala C., RA Arold S.T.; RT "Structural basis for the interaction between focal adhesion kinase RT and CD4."; RL J. Mol. Biol. 375:1320-1328(2008). CC -!- FUNCTION: Integral membrane glycoprotein that plays an essential CC role in the immune response and serves multiple functions in CC responses against both external and internal offenses. In T-cells, CC functions primarily as a coreceptor for MHC class II CC molecule:peptide complex. The antigens presented by class II CC peptides are derived from extracellular proteins while class I CC peptides are derived from cytosolic proteins. Interacts CC simultaneously with the T-cell receptor (TCR) and the MHC class II CC presented by antigen presenting cells (APCs). In turn, recruits CC the Src kinase LCK to the vicinity of the TCR-CD3 complex. LCK CC then initiates different intracellular signaling pathways by CC phosphorylating various substrates ultimately leading to CC lymphokine production, motility, adhesion and activation of T- CC helper cells. In other cells such as macrophages or NK cells, CC plays a role in differentiation/activation, cytokine expression CC and cell migration in a TCR/LCK-independent pathway. Participates CC in the development of T-helper cells in the thymus and triggers CC the differentiation of monocytes into functional mature CC macrophages. {ECO:0000269|PubMed:16951326, CC ECO:0000269|PubMed:24942581, ECO:0000269|PubMed:2823150}. CC -!- FUNCTION: (Microbial infection) Primary receptor for human CC immunodeficiency virus-1 (HIV-1) (PubMed:2214026, PubMed:16331979, CC PubMed:9641677, PubMed:12089508). Down-regulated by HIV-1 Vpu CC (PubMed:17346169). Acts as a receptor for Human Herpes virus CC 7/HHV-7 (PubMed:7909607). {ECO:0000269|PubMed:12089508, CC ECO:0000269|PubMed:16331979, ECO:0000269|PubMed:17346169, CC ECO:0000269|PubMed:2214026, ECO:0000269|PubMed:7909607, CC ECO:0000269|PubMed:9641677}. CC -!- SUBUNIT: Forms disulfide-linked homo-dimers at the cell surface. CC Interacts with LCK (PubMed:16888650). Interacts with PTK2/FAK1. CC Binds to P4HB/PDI. Interacts with IL16; this interaction induces a CC CD4-dependent signaling in lymphocytes. CC {ECO:0000269|PubMed:11113139, ECO:0000269|PubMed:12089508, CC ECO:0000269|PubMed:1673145, ECO:0000269|PubMed:16888650, CC ECO:0000269|PubMed:18078954}. CC -!- SUBUNIT: (Microbial infection) Interacts with HIV-1 Envelope CC polyprotein gp160 and protein Vpu (PubMed:2214026, CC PubMed:16331979, PubMed:9641677). {ECO:0000269|PubMed:16331979, CC ECO:0000269|PubMed:2214026, ECO:0000269|PubMed:9641677}. CC -!- SUBUNIT: (Microbial infection) Interacts with Human Herpes virus 7 CC surface proteins. {ECO:0000269|PubMed:7909607}. CC -!- INTERACTION: CC Self; NbExp=2; IntAct=EBI-353826, EBI-353826; CC P51681:CCR5; NbExp=2; IntAct=EBI-353826, EBI-489374; CC P04578:env (xeno); NbExp=2; IntAct=EBI-353826, EBI-6163496; CC Q1PHM6:env (xeno); NbExp=2; IntAct=EBI-353826, EBI-15845606; CC Q2N0S6:env (xeno); NbExp=3; IntAct=EBI-353826, EBI-16080048; CC P06239:LCK; NbExp=2; IntAct=EBI-353826, EBI-1348; CC P03407:nef (xeno); NbExp=2; IntAct=EBI-353826, EBI-7355020; CC P04150:NR3C1; NbExp=2; IntAct=EBI-353826, EBI-493507; CC P05919:vpu (xeno); NbExp=3; IntAct=EBI-353826, EBI-6248147; CC -!- SUBCELLULAR LOCATION: Cell membrane {ECO:0000269|PubMed:12089508, CC ECO:0000269|PubMed:12517957, ECO:0000269|PubMed:2823150, CC ECO:0000269|PubMed:2990730}; Single-pass type I membrane protein CC {ECO:0000269|PubMed:12517957, ECO:0000269|PubMed:15340161, CC ECO:0000269|PubMed:1708753}. Note=Localizes to lipid rafts CC (PubMed:12517957, PubMed:9168119). Removed from plasma membrane by CC HIV-1 Nef protein that increases clathrin-dependent endocytosis of CC this antigen to target it to lysosomal degradation. Cell surface CC expression is also down-modulated by HIV-1 Envelope polyprotein CC gp160 that interacts with, and sequesters CD4 in the endoplasmic CC reticulum. CC -!- TISSUE SPECIFICITY: Highly expressed in T-helper cells. The CC presence of CD4 is a hallmark of T-helper cells which are CC specialized in the activation and growth of cytotoxic T-cells, CC regulation of B cells, or activation of phagocytes. CD4 is also CC present in other immune cells such as macrophages, dendritic cells CC or NK cells. {ECO:0000269|PubMed:16951326, CC ECO:0000269|PubMed:24942581, ECO:0000269|PubMed:8088877}. CC -!- PTM: Palmitoylation and association with LCK contribute to the CC enrichment of CD4 in lipid rafts. {ECO:0000269|PubMed:1618861}. CC -!- PTM: Phosphorylated by PKC; phosphorylation at Ser-433 plays an CC important role for CD4 internalization. CC {ECO:0000269|PubMed:2105883, ECO:0000269|PubMed:2512251}. CC -!- POLYMORPHISM: The OKT monoclonal antibodies are widely used for CC the analysis of human peripheral blood T-lymphocytes. OKT4 reacts CC with T-helper/inducer lymphocytes. The OKT4 epitope of the CD4 CC cell-surface protein is polymorphic in white, black, and Japanese CC populations. The variable phenotypic expression is due a CD4 CC polymorphism. OKT4 positive individuals carry Arg-265 and OKT4 CC negative individuals carry Trp-265 [MIM:613949]. CC {ECO:0000269|PubMed:1708753, ECO:0000269|PubMed:1961196}. CC -!- WEB RESOURCE: Name=NIEHS-SNPs; CC URL="http://egp.gs.washington.edu/data/cd4/"; CC -!- WEB RESOURCE: Name=Wikipedia; Note=CD4 entry; CC URL="https://en.wikipedia.org/wiki/CD4"; CC ----------------------------------------------------------------------- CC Copyrighted by the UniProt Consortium, see https://www.uniprot.org/terms CC Distributed under the Creative Commons Attribution (CC BY 4.0) License CC ----------------------------------------------------------------------- DR EMBL; M12807; AAA35572.1; -; mRNA. DR EMBL; U47924; AAB51309.1; -; Genomic_DNA. DR EMBL; M35160; AAA16069.1; -; mRNA. DR EMBL; BT019791; AAV38594.1; -; mRNA. DR EMBL; BT019811; AAV38614.1; -; mRNA. DR EMBL; DQ012936; AAY22175.1; -; Genomic_DNA. DR EMBL; AK312828; BAG35684.1; -; mRNA. DR EMBL; CH471116; EAW88738.1; -; Genomic_DNA. DR EMBL; CH471116; EAW88739.1; -; Genomic_DNA. DR EMBL; BC025782; AAH25782.1; -; mRNA. DR CCDS; CCDS8562.1; -. DR PIR; A90872; RWHUT4. DR RefSeq; NP_000607.1; NM_000616.4. DR UniGene; Hs.631659; -. DR PDB; 1CDH; X-ray; 2.30 A; A=26-203. DR PDB; 1CDI; X-ray; 2.90 A; A=26-203. DR PDB; 1CDJ; X-ray; 2.50 A; A=26-203. DR PDB; 1CDU; X-ray; 2.70 A; A=26-203. DR PDB; 1CDY; X-ray; 2.00 A; A=26-203. DR PDB; 1G9M; X-ray; 2.20 A; C=26-208. DR PDB; 1G9N; X-ray; 2.90 A; C=26-208. DR PDB; 1GC1; X-ray; 2.50 A; C=26-206. DR PDB; 1JL4; X-ray; 4.30 A; D=26-203. DR PDB; 1OPN; Model; -; C=26-206. DR PDB; 1OPT; Model; -; C=26-206. DR PDB; 1OPW; Model; -; C=26-206. DR PDB; 1Q68; NMR; -; A=421-458. DR PDB; 1RZJ; X-ray; 2.20 A; C=26-208. DR PDB; 1RZK; X-ray; 2.90 A; C=26-208. DR PDB; 1WBR; NMR; -; A=428-444. DR PDB; 1WIO; X-ray; 3.90 A; A/B=26-388. DR PDB; 1WIP; X-ray; 4.00 A; A/B=26-388. DR PDB; 1WIQ; X-ray; 5.00 A; A/B=26-388. DR PDB; 2B4C; X-ray; 3.30 A; C=26-206. DR PDB; 2JKR; X-ray; 2.98 A; P/Q=431-441. DR PDB; 2JKT; X-ray; 3.40 A; P/Q=435-441. DR PDB; 2KLU; NMR; -; A=397-458. DR PDB; 2NXY; X-ray; 2.00 A; B=26-208. DR PDB; 2NXZ; X-ray; 2.04 A; B=26-208. DR PDB; 2NY0; X-ray; 2.20 A; B=26-208. DR PDB; 2NY1; X-ray; 1.99 A; B=26-208. DR PDB; 2NY2; X-ray; 2.00 A; B=26-208. DR PDB; 2NY3; X-ray; 2.00 A; B=26-208. DR PDB; 2NY4; X-ray; 2.00 A; B=26-208. DR PDB; 2NY5; X-ray; 2.50 A; C=26-208. DR PDB; 2NY6; X-ray; 2.80 A; B=26-208. DR PDB; 2QAD; X-ray; 3.30 A; B/F=26-206. DR PDB; 3B71; X-ray; 2.82 A; D/E/F=428-450. DR PDB; 3CD4; X-ray; 2.20 A; A=26-207. DR PDB; 3J70; EM; -; C/O/T=26-208. DR PDB; 3JCB; EM; -; D=26-200. DR PDB; 3JCC; EM; -; D=26-200. DR PDB; 3JWD; X-ray; 2.61 A; C/D=26-208. DR PDB; 3JWO; X-ray; 3.51 A; C=26-208. DR PDB; 3LQA; X-ray; 3.40 A; C=26-207. DR PDB; 3O2D; X-ray; 2.19 A; A=26-207. DR PDB; 3S4S; X-ray; 2.40 A; G/H=26-203. DR PDB; 3S5L; X-ray; 2.10 A; G/H=26-203. DR PDB; 3T0E; X-ray; 4.00 A; E=26-388. DR PDB; 4H8W; X-ray; 1.85 A; C=26-208. DR PDB; 4JM2; X-ray; 3.10 A; F=26-208. DR PDB; 4P9H; X-ray; 3.00 A; C=26-207. DR PDB; 4Q6I; X-ray; 3.65 A; C/I/J/K=1-208. DR PDB; 4R2G; X-ray; 3.28 A; B/F/H/L=26-208. DR PDB; 4R4H; X-ray; 4.28 A; B=26-203. DR PDB; 4RQS; X-ray; 4.49 A; B=26-208. DR PDB; 5A7X; EM; 17.00 A; B/F/J=26-206. DR PDB; 5A8H; EM; 23.00 A; B/H/N=26-208. DR PDB; 5CAY; X-ray; 3.00 A; B=26-208. DR PDB; 5THR; EM; 8.90 A; G/H/I=26-207. DR PDB; 5U1F; EM; 6.80 A; M=26-388. DR PDB; 5VN3; EM; 3.70 A; C/E/F=26-208. DR PDB; 6CM3; EM; 3.54 A; G/H/I=26-207. DR PDB; 6EDU; EM; 4.06 A; G/H/I=26-208. DR PDB; 6MEO; EM; 3.90 A; A=26-201. DR PDB; 6MET; EM; 4.50 A; A=26-388. DR PDBsum; 1CDH; -. DR PDBsum; 1CDI; -. DR PDBsum; 1CDJ; -. DR PDBsum; 1CDU; -. DR PDBsum; 1CDY; -. DR PDBsum; 1G9M; -. DR PDBsum; 1G9N; -. DR PDBsum; 1GC1; -. DR PDBsum; 1JL4; -. DR PDBsum; 1OPN; -. DR PDBsum; 1OPT; -. DR PDBsum; 1OPW; -. DR PDBsum; 1Q68; -. DR PDBsum; 1RZJ; -. DR PDBsum; 1RZK; -. DR PDBsum; 1WBR; -. DR PDBsum; 1WIO; -. DR PDBsum; 1WIP; -. DR PDBsum; 1WIQ; -. DR PDBsum; 2B4C; -. DR PDBsum; 2JKR; -. DR PDBsum; 2JKT; -. DR PDBsum; 2KLU; -. DR PDBsum; 2NXY; -. DR PDBsum; 2NXZ; -. DR PDBsum; 2NY0; -. DR PDBsum; 2NY1; -. DR PDBsum; 2NY2; -. DR PDBsum; 2NY3; -. DR PDBsum; 2NY4; -. DR PDBsum; 2NY5; -. DR PDBsum; 2NY6; -. DR PDBsum; 2QAD; -. DR PDBsum; 3B71; -. DR PDBsum; 3CD4; -. DR PDBsum; 3J70; -. DR PDBsum; 3JCB; -. DR PDBsum; 3JCC; -. DR PDBsum; 3JWD; -. DR PDBsum; 3JWO; -. DR PDBsum; 3LQA; -. DR PDBsum; 3O2D; -. DR PDBsum; 3S4S; -. DR PDBsum; 3S5L; -. DR PDBsum; 3T0E; -. DR PDBsum; 4H8W; -. DR PDBsum; 4JM2; -. DR PDBsum; 4P9H; -. DR PDBsum; 4Q6I; -. DR PDBsum; 4R2G; -. DR PDBsum; 4R4H; -. DR PDBsum; 4RQS; -. DR PDBsum; 5A7X; -. DR PDBsum; 5A8H; -. DR PDBsum; 5CAY; -. DR PDBsum; 5THR; -. DR PDBsum; 5U1F; -. DR PDBsum; 5VN3; -. DR PDBsum; 6CM3; -. DR PDBsum; 6EDU; -. DR PDBsum; 6MEO; -. DR PDBsum; 6MET; -. DR DisProt; DP00123; -. DR ProteinModelPortal; P01730; -. DR SMR; P01730; -. DR BioGrid; 107358; 94. DR DIP; DIP-617N; -. DR ELM; P01730; -. DR IntAct; P01730; 24. DR MINT; P01730; -. DR STRING; 9606.ENSP00000011653; -. DR BindingDB; P01730; -. DR ChEMBL; CHEMBL2754; -. DR DrugBank; DB00098; Anti-thymocyte Globulin (Rabbit). DR GlyConnect; 587; -. DR iPTMnet; P01730; -. DR PhosphoSitePlus; P01730; -. DR SwissPalm; P01730; -. DR UniCarbKB; P01730; -. DR BioMuta; CD4; -. DR DMDM; 116013; -. DR jPOST; P01730; -. DR MaxQB; P01730; -. DR PaxDb; P01730; -. DR PeptideAtlas; P01730; -. DR PRIDE; P01730; -. DR ProteomicsDB; 51451; -. DR DNASU; 920; -. DR Ensembl; ENST00000011653; ENSP00000011653; ENSG00000010610. DR GeneID; 920; -. DR KEGG; hsa:920; -. DR UCSC; uc001qqv.3; human. DR CTD; 920; -. DR DisGeNET; 920; -. DR EuPathDB; HostDB:ENSG00000010610.9; -. DR GeneCards; CD4; -. DR HGNC; HGNC:1678; CD4. DR HPA; CAB000011; -. DR HPA; CAB068180; -. DR HPA; HPA004252; -. DR HPA; HPA004472; -. DR MalaCards; CD4; -. DR MIM; 186940; gene. DR MIM; 613949; phenotype. DR neXtProt; NX_P01730; -. DR OpenTargets; ENSG00000010610; -. DR PharmGKB; PA26220; -. DR eggNOG; ENOG410IK9F; Eukaryota. DR eggNOG; ENOG410YWI4; LUCA. DR GeneTree; ENSGT00390000001745; -. DR HOGENOM; HOG000008696; -. DR HOVERGEN; HBG005281; -. DR InParanoid; P01730; -. DR KO; K06454; -. DR OMA; CEVWGPT; -. DR OrthoDB; 652984at2759; -. DR PhylomeDB; P01730; -. DR TreeFam; TF335974; -. DR Reactome; R-HSA-1462054; Alpha-defensins. DR Reactome; R-HSA-167590; Nef Mediated CD4 Down-regulation. DR Reactome; R-HSA-173107; Binding and entry of HIV virion. DR Reactome; R-HSA-180534; Vpu mediated degradation of CD4. DR Reactome; R-HSA-202424; Downstream TCR signaling. DR Reactome; R-HSA-202427; Phosphorylation of CD3 and TCR zeta chains. DR Reactome; R-HSA-202430; Translocation of ZAP-70 to Immunological synapse. DR Reactome; R-HSA-202433; Generation of second messenger molecules. DR Reactome; R-HSA-389948; PD-1 signaling. DR Reactome; R-HSA-449836; Other interleukin signaling. DR Reactome; R-HSA-8856825; Cargo recognition for clathrin-mediated endocytosis. DR Reactome; R-HSA-8856828; Clathrin-mediated endocytosis. DR SignaLink; P01730; -. DR SIGNOR; P01730; -. DR ChiTaRS; CD4; human. DR EvolutionaryTrace; P01730; -. DR GeneWiki; CD4; -. DR GenomeRNAi; 920; -. DR PRO; PR:P01730; -. DR Proteomes; UP000005640; Chromosome 12. DR Bgee; ENSG00000010610; Expressed in 189 organ(s), highest expression level in leukocyte. DR ExpressionAtlas; P01730; baseline and differential. DR Genevisible; P01730; HS. DR GO; GO:0030665; C:clathrin-coated vesicle membrane; TAS:Reactome. DR GO; GO:0005769; C:early endosome; TAS:Reactome. DR GO; GO:0005788; C:endoplasmic reticulum lumen; IEA:Ensembl. DR GO; GO:0005789; C:endoplasmic reticulum membrane; TAS:Reactome. DR GO; GO:0009897; C:external side of plasma membrane; IDA:MGI. DR GO; GO:0005887; C:integral component of plasma membrane; IDA:CAFA. DR GO; GO:0045121; C:membrane raft; IDA:UniProtKB. DR GO; GO:0005886; C:plasma membrane; IDA:UniProtKB. DR GO; GO:0042101; C:T cell receptor complex; NAS:UniProtKB. DR GO; GO:0015026; F:coreceptor activity; TAS:ProtInc. DR GO; GO:0019899; F:enzyme binding; IPI:UniProtKB. DR GO; GO:0005201; F:extracellular matrix structural constituent; NAS:UniProtKB. DR GO; GO:0042802; F:identical protein binding; IPI:IntAct. DR GO; GO:0019865; F:immunoglobulin binding; IEA:Ensembl. DR GO; GO:0042011; F:interleukin-16 binding; IPI:CAFA. DR GO; GO:0042012; F:interleukin-16 receptor activity; IDA:CAFA. DR GO; GO:0042289; F:MHC class II protein binding; IDA:UniProtKB. DR GO; GO:0042803; F:protein homodimerization activity; IDA:UniProtKB. DR GO; GO:0019901; F:protein kinase binding; IPI:UniProtKB. DR GO; GO:1990782; F:protein tyrosine kinase binding; IPI:UniProtKB. DR GO; GO:0038023; F:signaling receptor activity; TAS:ProtInc. DR GO; GO:0004888; F:transmembrane signaling receptor activity; TAS:ProtInc. DR GO; GO:0001618; F:virus receptor activity; IEA:UniProtKB-KW. DR GO; GO:0008270; F:zinc ion binding; IDA:UniProtKB. DR GO; GO:0002250; P:adaptive immune response; IEA:UniProtKB-KW. DR GO; GO:0007155; P:cell adhesion; IEA:InterPro. DR GO; GO:0007166; P:cell surface receptor signaling pathway; TAS:ProtInc. DR GO; GO:0097011; P:cellular response to granulocyte macrophage colony-stimulating factor stimulus; IDA:CAFA. DR GO; GO:0001816; P:cytokine production; IEA:Ensembl. DR GO; GO:0019221; P:cytokine-mediated signaling pathway; TAS:Reactome. DR GO; GO:0050829; P:defense response to Gram-negative bacterium; IEA:Ensembl. DR GO; GO:0030260; P:entry into host cell; TAS:Reactome. DR GO; GO:0007167; P:enzyme linked receptor protein signaling pathway; TAS:ProtInc. DR GO; GO:0019064; P:fusion of virus membrane with host plasma membrane; TAS:Reactome. DR GO; GO:0035397; P:helper T cell enhancement of adaptive immune response; IEA:Ensembl. DR GO; GO:0006955; P:immune response; NAS:UniProtKB. DR GO; GO:0006948; P:induction by virus of host cell-cell fusion; IDA:UniProtKB. DR GO; GO:0035723; P:interleukin-15-mediated signaling pathway; IDA:CAFA. DR GO; GO:0032507; P:maintenance of protein location in cell; IDA:MGI. DR GO; GO:0061024; P:membrane organization; TAS:Reactome. DR GO; GO:0010524; P:positive regulation of calcium ion transport into cytosol; IEA:Ensembl. DR GO; GO:0050850; P:positive regulation of calcium-mediated signaling; IEA:Ensembl. DR GO; GO:0070374; P:positive regulation of ERK1 and ERK2 cascade; IDA:CAFA. DR GO; GO:0043123; P:positive regulation of I-kappaB kinase/NF-kappaB signaling; IDA:CAFA. DR GO; GO:0045086; P:positive regulation of interleukin-2 biosynthetic process; NAS:UniProtKB. DR GO; GO:0033674; P:positive regulation of kinase activity; IDA:CAFA. DR GO; GO:0043410; P:positive regulation of MAPK cascade; IDA:CAFA. DR GO; GO:0045657; P:positive regulation of monocyte differentiation; IDA:CAFA. DR GO; GO:0050731; P:positive regulation of peptidyl-tyrosine phosphorylation; IEA:Ensembl. DR GO; GO:0045860; P:positive regulation of protein kinase activity; IDA:UniProtKB. DR GO; GO:0001934; P:positive regulation of protein phosphorylation; IDA:CAFA. DR GO; GO:0042102; P:positive regulation of T cell proliferation; IEA:Ensembl. DR GO; GO:0045893; P:positive regulation of transcription, DNA-templated; IDA:CAFA. DR GO; GO:0046598; P:positive regulation of viral entry into host cell; IDA:CAFA. DR GO; GO:0051924; P:regulation of calcium ion transport; IDA:CAFA. DR GO; GO:0050690; P:regulation of defense response to virus by virus; TAS:Reactome. DR GO; GO:0050863; P:regulation of T cell activation; IDA:UniProtKB. DR GO; GO:0032355; P:response to estradiol; IEA:Ensembl. DR GO; GO:0033280; P:response to vitamin D; IEA:Ensembl. DR GO; GO:0007165; P:signal transduction; TAS:ProtInc. DR GO; GO:0042110; P:T cell activation; IBA:GO_Central. DR GO; GO:0030217; P:T cell differentiation; IDA:UniProtKB. DR GO; GO:0050852; P:T cell receptor signaling pathway; TAS:Reactome. DR GO; GO:0045058; P:T cell selection; IDA:UniProtKB. DR GO; GO:0007169; P:transmembrane receptor protein tyrosine kinase signaling pathway; NAS:UniProtKB. DR Gene3D; 2.60.40.10; -; 4. DR InterPro; IPR000973; CD4. DR InterPro; IPR015274; CD4-extracel. DR InterPro; IPR007110; Ig-like_dom. DR InterPro; IPR036179; Ig-like_dom_sf. DR InterPro; IPR013783; Ig-like_fold. DR InterPro; IPR008424; Ig_C2-set. DR InterPro; IPR003599; Ig_sub. DR InterPro; IPR003598; Ig_sub2. DR InterPro; IPR013106; Ig_V-set. DR InterPro; IPR013151; Immunoglobulin. DR InterPro; IPR021963; Tcell_CD4_Cterm. DR PANTHER; PTHR11422:SF0; PTHR11422:SF0; 1. DR Pfam; PF05790; C2-set; 2. DR Pfam; PF09191; CD4-extracel; 1. DR Pfam; PF00047; ig; 1. DR Pfam; PF12104; Tcell_CD4_C; 1. DR PRINTS; PR00692; CD4TCANTIGEN. DR SMART; SM00409; IG; 3. DR SMART; SM00408; IGc2; 2. DR SMART; SM00406; IGv; 1. DR SUPFAM; SSF48726; SSF48726; 4. DR PROSITE; PS50835; IG_LIKE; 1. PE 1: Evidence at protein level; KW 3D-structure; Adaptive immunity; Cell membrane; Complete proteome; KW Direct protein sequencing; Disulfide bond; Glycoprotein; KW Host cell receptor for virus entry; Host-virus interaction; Immunity; KW Immunoglobulin domain; Lipoprotein; Membrane; Palmitate; KW Phosphoprotein; Polymorphism; Receptor; Reference proteome; Repeat; KW Signal; Transmembrane; Transmembrane helix. FT SIGNAL 1 25 {ECO:0000269|PubMed:15340161, FT ECO:0000269|PubMed:2592374}. FT CHAIN 26 458 T-cell surface glycoprotein CD4. FT /FTId=PRO_0000014621. FT TOPO_DOM 26 396 Extracellular. {ECO:0000255}. FT TRANSMEM 397 418 Helical. {ECO:0000255}. FT TOPO_DOM 419 458 Cytoplasmic. {ECO:0000255}. FT DOMAIN 26 125 Ig-like V-type. FT DOMAIN 126 203 Ig-like C2-type 1. FT DOMAIN 204 317 Ig-like C2-type 2. FT DOMAIN 318 374 Ig-like C2-type 3. FT REGION 427 455 HIV-1 Vpu-susceptibility domain. FT MOD_RES 433 433 Phosphoserine. FT {ECO:0000269|PubMed:2105883}. FT MOD_RES 440 440 Phosphoserine. FT {ECO:0000269|PubMed:2105883}. FT MOD_RES 456 456 Phosphoserine. FT {ECO:0000269|PubMed:2105883}. FT LIPID 419 419 S-palmitoyl cysteine. FT {ECO:0000269|PubMed:1618861}. FT LIPID 422 422 S-palmitoyl cysteine. FT {ECO:0000269|PubMed:1618861}. FT CARBOHYD 296 296 N-linked (GlcNAc...) asparagine. FT {ECO:0000269|PubMed:19159218, FT ECO:0000269|PubMed:2001369, FT ECO:0000269|PubMed:2592374}. FT /FTId=CAR_000053. FT CARBOHYD 325 325 N-linked (GlcNAc...) asparagine. FT {ECO:0000269|PubMed:2001369, FT ECO:0000269|PubMed:2592374}. FT /FTId=CAR_000054. FT DISULFID 41 109 {ECO:0000255|PROSITE-ProRule:PRU00114, FT ECO:0000269|PubMed:2592374}. FT DISULFID 155 184 {ECO:0000255|PROSITE-ProRule:PRU00114, FT ECO:0000269|PubMed:2592374}. FT DISULFID 328 370 {ECO:0000255|PROSITE-ProRule:PRU00114, FT ECO:0000269|PubMed:2592374}. FT VARIANT 191 191 K -> E (in dbSNP:rs28917504). FT {ECO:0000269|Ref.8}. FT /FTId=VAR_023459. FT VARIANT 227 227 F -> S (in dbSNP:rs11064419). FT {ECO:0000269|Ref.8}. FT /FTId=VAR_023460. FT VARIANT 265 265 R -> W (in OKT4-negative populations; FT dbSNP:rs28919570). FT {ECO:0000269|PubMed:1708753, FT ECO:0000269|PubMed:1961196, FT ECO:0000269|Ref.8}. FT /FTId=VAR_003906. FT MUTAGEN 432 432 M->T: No effect. FT {ECO:0000269|PubMed:8124721}. FT MUTAGEN 433 433 S->A: About 75% loss of internalization. FT {ECO:0000269|PubMed:2105883}. FT MUTAGEN 433 433 S->A: No effect. FT {ECO:0000269|PubMed:8124721}. FT MUTAGEN 438 439 LL->AA: Loss of Nef-induced CD4 down- FT modulation. {ECO:0000269|PubMed:8124721}. FT MUTAGEN 440 440 S->L: No effect. FT {ECO:0000269|PubMed:8124721}. FT MUTAGEN 445 445 C->A: Loss of homodimerization; when FT associated with A-447. FT {ECO:0000269|PubMed:9168119}. FT MUTAGEN 447 447 C->A: Loss of homodimerization; when FT associated with A-445. FT {ECO:0000269|PubMed:9168119}. FT MUTAGEN 457 458 Missing: Abolished interaction with SPG21 FT and induced T-cell activation. FT {ECO:0000269|PubMed:11113139}. FT STRAND 27 32 {ECO:0000244|PDB:4H8W}. FT STRAND 37 39 {ECO:0000244|PDB:4H8W}. FT STRAND 44 47 {ECO:0000244|PDB:4H8W}. FT STRAND 51 55 {ECO:0000244|PDB:4H8W}. FT STRAND 56 58 {ECO:0000244|PDB:3LQA}. FT STRAND 60 65 {ECO:0000244|PDB:4H8W}. FT STRAND 68 71 {ECO:0000244|PDB:4H8W}. FT STRAND 73 76 {ECO:0000244|PDB:2NY6}. FT HELIX 77 79 {ECO:0000244|PDB:4H8W}. FT HELIX 84 89 {ECO:0000244|PDB:4H8W}. FT STRAND 94 96 {ECO:0000244|PDB:4H8W}. FT HELIX 101 103 {ECO:0000244|PDB:4H8W}. FT STRAND 105 111 {ECO:0000244|PDB:4H8W}. FT STRAND 114 129 {ECO:0000244|PDB:4H8W}. FT STRAND 131 134 {ECO:0000244|PDB:2NY1}. FT STRAND 135 137 {ECO:0000244|PDB:1G9N}. FT STRAND 139 144 {ECO:0000244|PDB:4H8W}. FT STRAND 152 156 {ECO:0000244|PDB:4H8W}. FT STRAND 158 160 {ECO:0000244|PDB:1CDJ}. FT STRAND 162 164 {ECO:0000244|PDB:4H8W}. FT STRAND 166 171 {ECO:0000244|PDB:4H8W}. FT HELIX 176 178 {ECO:0000244|PDB:4H8W}. FT STRAND 180 188 {ECO:0000244|PDB:4H8W}. FT STRAND 191 200 {ECO:0000244|PDB:4H8W}. FT HELIX 398 421 {ECO:0000244|PDB:2KLU}. FT STRAND 426 428 {ECO:0000244|PDB:2KLU}. FT HELIX 432 438 {ECO:0000244|PDB:3B71}. FT STRAND 440 442 {ECO:0000244|PDB:1WBR}. SQ SEQUENCE 458 AA; 51111 MW; 20ED893F9E56D236 CRC64; MNRGVPFRHL LLVLQLALLP AATQGKKVVL GKKGDTVELT CTASQKKSIQ FHWKNSNQIK ILGNQGSFLT KGPSKLNDRA DSRRSLWDQG NFPLIIKNLK IEDSDTYICE VEDQKEEVQL LVFGLTANSD THLLQGQSLT LTLESPPGSS PSVQCRSPRG KNIQGGKTLS VSQLELQDSG TWTCTVLQNQ KKVEFKIDIV VLAFQKASSI VYKKEGEQVE FSFPLAFTVE KLTGSGELWW QAERASSSKS WITFDLKNKE VSVKRVTQDP KLQMGKKLPL HLTLPQALPQ YAGSGNLTLA LEAKTGKLHQ EVNLVVMRAT QLQKNLTCEV WGPTSPKLML SLKLENKEAK VSKREKAVWV LNPEAGMWQC LLSDSGQVLL ESNIKVLPTW STPVQPMALI VLGGVAGLLL FIGLGIFFCV RCRHRRRQAE RMSQIKRLLS EKKTCQCPHR FQKTCSPI //