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Entry version 88 (08 May 2019)
Sequence version 1 (01 May 1999)
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Protein

CD81 antigen

Gene

CD81

Organism
Chlorocebus aethiops (Green monkey) (Cercopithecus aethiops)
Status
Reviewed-Annotation score:

Annotation score:5 out of 5

<p>The annotation score provides a heuristic measure of the annotation content of a UniProtKB entry or proteome. This score <strong>cannot</strong> be used as a measure of the accuracy of the annotation as we cannot define the ‘correct annotation’ for any given protein.<p><a href='/help/annotation_score' target='_top'>More...</a></p>
-Experimental evidence at transcript leveli <p>This indicates the type of evidence that supports the existence of the protein. Note that the ‘protein existence’ evidence does not give information on the accuracy or correctness of the sequence(s) displayed.<p><a href='/help/protein_existence' target='_top'>More...</a></p>

<p>This section provides any useful information about the protein, mostly biological knowledge.<p><a href='/help/function_section' target='_top'>More...</a></p>Functioni

Structural component of specialized membrane microdomains known as tetraspanin-enriched microdomains (TERMs), which act as platforms for receptor clustering and signaling. Essential for trafficking and compartmentalization of CD19 receptor on the surface of activated B cells. Upon initial encounter with microbial pathogens, enables the assembly of CD19-CR2/CD21 and B cell receptor (BCR) complexes at signaling TERMs, lowering the threshold dose of antigen required to trigger B cell clonal expansion and antibody production. In T cells, facilitates the localization of CD247/CD3 zeta at antigen-induced synapses with B cells, providing for costimulation and polarization toward T helper type 2 phenotype. Present in MHC class II compartments, may also play a role in antigen presentation (By similarity). Can act both as positive and negative regulator of homotypic or heterotypic cell-cell fusion processes. Positively regulates sperm-egg fusion and may be involved in acrosome reaction. In myoblasts, associates with CD9 and PTGFRN and inhibits myotube fusion during muscle regeneration (By similarity). In macrophages, associates with CD9 and beta-1 and beta-2 integrins, and prevents macrophage fusion into multinucleated giant cells specialized in ingesting complement-opsonized large particles (By similarity). Also prevents the fusion of mononuclear cell progenitors into osteoclasts in charge of bone resorption (By similarity). May regulate the compartmentalization of enzymatic activities. In T cells, defines the subcellular localization of dNTPase SAMHD1 and permits its degradation by the proteasome, thereby controlling intracellular dNTP levels (By similarity). Also involved in cell adhesion and motility. Positively regulates integrin-mediated adhesion of macrophages, particularly relevant for the inflammatory response in the lung (By similarity).By similarity

Sites

Feature keyPosition(s)DescriptionActionsGraphical viewLength
<p>This subsection describes interesting single amino acid sites on the sequence that are not defined in any other subsection. This subsection can be displayed in different sections (‘Function’, ‘PTM / Processing’, ‘Pathology and Biotech’) according to its content.<p><a href='/help/site' target='_top'>More...</a></p>Sitei116Important for interaction with integrinBy similarity1
Sitei144Important for interaction with integrinBy similarity1
Sitei148Important for interaction with integrinBy similarity1
<p>This subsection of the <a href="http://www.uniprot.org/help/function_section">Function</a> section describes the interaction between a single amino acid and another chemical entity. Priority is given to the annotation of physiological ligands.<p><a href='/help/binding' target='_top'>More...</a></p>Binding sitei219CholesterolBy similarity1

<p>The <a href="http://www.geneontology.org/">Gene Ontology (GO)</a> project provides a set of hierarchical controlled vocabulary split into 3 categories:<p><a href='/help/gene_ontology' target='_top'>More...</a></p>GO - Molecular functioni

GO - Biological processi

<p>UniProtKB Keywords constitute a <a href="http://www.uniprot.org/keywords">controlled vocabulary</a> with a hierarchical structure. Keywords summarise the content of a UniProtKB entry and facilitate the search for proteins of interest.<p><a href='/help/keywords' target='_top'>More...</a></p>Keywordsi

Biological processAdaptive immunity, Immunity
LigandLipid-binding

<p>This section provides information about the protein and gene name(s) and synonym(s) and about the organism that is the source of the protein sequence.<p><a href='/help/names_and_taxonomy_section' target='_top'>More...</a></p>Names & Taxonomyi

<p>This subsection of the <a href="http://www.uniprot.org/help/names_and_taxonomy_section">Names and taxonomy</a> section provides an exhaustive list of all names of the protein, from commonly used to obsolete, to allow unambiguous identification of a protein.<p><a href='/help/protein_names' target='_top'>More...</a></p>Protein namesi
Recommended name:
CD81 antigen
Alternative name(s):
CD_antigen: CD81
<p>This subsection of the <a href="http://www.uniprot.org/help/names_and_taxonomy_section">Names and taxonomy</a> section indicates the name(s) of the gene(s) that code for the protein sequence(s) described in the entry. Four distinct tokens exist: ‘Name’, ‘Synonyms’, ‘Ordered locus names’ and ‘ORF names’.<p><a href='/help/gene_name' target='_top'>More...</a></p>Gene namesi
Name:CD81
<p>This subsection of the <a href="http://www.uniprot.org/help/names_and_taxonomy_section">Names and taxonomy</a> section provides information on the name(s) of the organism that is the source of the protein sequence.<p><a href='/help/organism-name' target='_top'>More...</a></p>OrganismiChlorocebus aethiops (Green monkey) (Cercopithecus aethiops)
<p>This subsection of the <a href="http://www.uniprot.org/help/names_and_taxonomy_section">Names and taxonomy</a> section shows the unique identifier assigned by the NCBI to the source organism of the protein. This is known as the ‘taxonomic identifier’ or ‘taxid’.<p><a href='/help/taxonomic_identifier' target='_top'>More...</a></p>Taxonomic identifieri9534 [NCBI]
<p>This subsection of the <a href="http://www.uniprot.org/help/names_and_taxonomy_section">Names and taxonomy</a> section contains the taxonomic hierarchical classification lineage of the source organism. It lists the nodes as they appear top-down in the taxonomic tree, with the more general grouping listed first.<p><a href='/help/taxonomic_lineage' target='_top'>More...</a></p>Taxonomic lineageiEukaryotaMetazoaChordataCraniataVertebrataEuteleostomiMammaliaEutheriaEuarchontogliresPrimatesHaplorrhiniCatarrhiniCercopithecidaeCercopithecinaeChlorocebus

<p>This section provides information on the location and the topology of the mature protein in the cell.<p><a href='/help/subcellular_location_section' target='_top'>More...</a></p>Subcellular locationi

Extracellular region or secreted Cytosol Plasma membrane Cytoskeleton Lysosome Endosome Peroxisome ER Golgi apparatus Nucleus Mitochondrion Manual annotation Automatic computational assertionGraphics by Christian Stolte & Seán O’Donoghue; Source: COMPARTMENTS

Topology

Feature keyPosition(s)DescriptionActionsGraphical viewLength
<p>This subsection of the <a href="http://www.uniprot.org/help/subcellular_location_section">'Subcellular location'</a> section describes the subcellular compartment where each non-membrane region of a membrane-spanning protein is found.<p><a href='/help/topo_dom' target='_top'>More...</a></p>Topological domaini1 – 12CytoplasmicCuratedAdd BLAST12
<p>This subsection of the <a href="http://www.uniprot.org/help/subcellular_location_section">'Subcellular location'</a> section describes the extent of a membrane-spanning region of the protein. It denotes the presence of both alpha-helical transmembrane regions and the membrane spanning regions of beta-barrel transmembrane proteins.<p><a href='/help/transmem' target='_top'>More...</a></p>Transmembranei13 – 33HelicalBy similarityAdd BLAST21
Topological domaini34 – 63ExtracellularCuratedAdd BLAST30
Transmembranei64 – 84HelicalBy similarityAdd BLAST21
Topological domaini85 – 89CytoplasmicCurated5
Transmembranei90 – 112HelicalBy similarityAdd BLAST23
Topological domaini113 – 201ExtracellularCuratedAdd BLAST89
Transmembranei202 – 224HelicalBy similarityAdd BLAST23
Topological domaini225 – 236CytoplasmicCuratedAdd BLAST12

Keywords - Cellular componenti

Cell membrane, Membrane

<p>This section describes post-translational modifications (PTMs) and/or processing events.<p><a href='/help/ptm_processing_section' target='_top'>More...</a></p>PTM / Processingi

Molecule processing

Feature keyPosition(s)DescriptionActionsGraphical viewLength
<p>This subsection of the ‘PTM / Processing’ section describes the extent of a polypeptide chain in the mature protein following processing.<p><a href='/help/chain' target='_top'>More...</a></p>ChainiPRO_00002192201 – 236CD81 antigenAdd BLAST236

Amino acid modifications

Feature keyPosition(s)DescriptionActionsGraphical viewLength
<p>This subsection of the PTM / Processing":/help/ptm_processing_section section describes the positions of cysteine residues participating in disulfide bonds.<p><a href='/help/disulfid' target='_top'>More...</a></p>Disulfide bondi156 ↔ 190By similarity
Disulfide bondi157 ↔ 175By similarity

<p>This subsection of the <a href="http://www.uniprot.org/help/ptm_processing_section">PTM/processing</a> section describes post-translational modifications (PTMs). This subsection <strong>complements</strong> the information provided at the sequence level or describes modifications for which <strong>position-specific data is not yet available</strong>.<p><a href='/help/post-translational_modification' target='_top'>More...</a></p>Post-translational modificationi

Not glycosylated.Curated
Likely constitutively palmitoylated at low levels. Protein palmitoylation is up-regulated upon coligation of BCR and CD9-C2R-CD81 complexes in lipid rafts.By similarity

Keywords - PTMi

Disulfide bond

<p>This section provides information on the quaternary structure of a protein and on interaction(s) with other proteins or protein complexes.<p><a href='/help/interaction_section' target='_top'>More...</a></p>Interactioni

<p>This subsection of the <a href="http://www.uniprot.org/help/interaction_section">'Interaction'</a> section provides information about the protein quaternary structure and interaction(s) with other proteins or protein complexes (with the exception of physiological receptor-ligand interactions which are annotated in the <a href="http://www.uniprot.org/help/function_section">'Function'</a> section).<p><a href='/help/subunit_structure' target='_top'>More...</a></p>Subunit structurei

Homodimer.

Part of a complex composed of CD19, CR2/CD21, CD81 and IFITM1/CD225 in the membrane of mature B cells.

Interacts (via the second extracellular domain) with CD19; this interaction is initiated early during biosynthesis in the ER and enables trafficking of only properly folded CD19.

Part of a complex that includes MHC class II/HLA-DR molecules and IFITM1.

Interacts with IFITM1 (By similarity).

Interacts with IFITM2 and IFITM3 (By similarity). Part of integrin-tetraspanin complex composed of CD9, CD81, beta-1 and beta-2 integrins in the membrane of monocyte/macrophages.

Interacts (via the second extracellular domain) with integrin ITGAV:ITGB3.

Interacts with CD247/CD3 zeta, ICAM1 and CD9 at the immune synapse on T cell membrane (By similarity).

Part of a GPCR-tetraspanin complex consisting at least of ADGRG1, CD81, possibly CD9, and GNA11 in which CD81 enhances the association of ADGRG1 with GNA11.

Part of a complex composed of CD9, CD81, PTGFRN and IGSF8 (By similarity).

Interacts directly with IGSF8.

Interacts with CD53 and SCIMP.

Interacts with SAMHD1 (via its C-terminus) (By similarity).

Interacts with glypican GPC3 and with the transcriptional repressor HHEX; binding to GPC3 decreases the availability of free CD81 for binding to HHEX, resulting in nuclear translocation of HHEX and transcriptional repression (By similarity).

Interacts with CLDN1.

Interacts with CLDN6 and CLDN9 (By similarity).

By similarity

GO - Molecular functioni

<p>This section provides information on the tertiary and secondary structure of a protein.<p><a href='/help/structure_section' target='_top'>More...</a></p>Structurei

3D structure databases

SWISS-MODEL Repository - a database of annotated 3D protein structure models

More...
SMRi
O97703

Database of comparative protein structure models

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ModBasei
Search...

<p>This section provides information on sequence similarities with other proteins and the domain(s) present in a protein.<p><a href='/help/family_and_domains_section' target='_top'>More...</a></p>Family & Domainsi

<p>This subsection of the ‘Family and domains’ section provides general information on the biological role of a domain. The term ‘domain’ is intended here in its wide acceptation, it may be a structural domain, a transmembrane region or a functional domain. Several domains are described in this subsection.<p><a href='/help/domain_cc' target='_top'>More...</a></p>Domaini

Binds cholesterol in a cavity lined by the transmembrane spans.By similarity

<p>This subsection of the ‘Family and domains’ section provides information about the sequence similarity with other proteins.<p><a href='/help/sequence_similarities' target='_top'>More...</a></p>Sequence similaritiesi

Belongs to the tetraspanin (TM4SF) family.Curated

Keywords - Domaini

Transmembrane, Transmembrane helix

Family and domain databases

Gene3D Structural and Functional Annotation of Protein Families

More...
Gene3Di
1.10.1450.10, 1 hit

Integrated resource of protein families, domains and functional sites

More...
InterProi
View protein in InterPro
IPR000301 Tetraspanin
IPR018499 Tetraspanin/Peripherin
IPR018503 Tetraspanin_CS
IPR008952 Tetraspanin_EC2_sf

Pfam protein domain database

More...
Pfami
View protein in Pfam
PF00335 Tetraspanin, 1 hit

PIRSF; a whole-protein classification database

More...
PIRSFi
PIRSF002419 Tetraspanin, 1 hit

Protein Motif fingerprint database; a protein domain database

More...
PRINTSi
PR00259 TMFOUR

Superfamily database of structural and functional annotation

More...
SUPFAMi
SSF48652 SSF48652, 1 hit

PROSITE; a protein domain and family database

More...
PROSITEi
View protein in PROSITE
PS00421 TM4_1, 1 hit

<p>This section displays by default the canonical protein sequence and upon request all isoforms described in the entry. It also includes information pertinent to the sequence(s), including <a href="http://www.uniprot.org/help/sequence_length">length</a> and <a href="http://www.uniprot.org/help/sequences">molecular weight</a>. The information is filed in different subsections. The current subsections and their content are listed below:<p><a href='/help/sequences_section' target='_top'>More...</a></p>Sequencei

<p>This subsection of the <a href="http://www.uniprot.org/help/sequences_section">Sequence</a> section indicates if the <a href="http://www.uniprot.org/help/canonical_and_isoforms">canonical sequence</a> displayed by default in the entry is complete or not.<p><a href='/help/sequence_status' target='_top'>More...</a></p>Sequence statusi: Complete.

O97703-1 [UniParc]FASTAAdd to basket
« Hide
        10         20         30         40         50
MGVEGCTKCI KYLLFVFNFV FWLAGGVILG VALWLRHDPQ TTNLLYLELG
60 70 80 90 100
DKPAPNTFYV GIYILIAVGA VMMFVGFLGC YGAIQESQCL LGTFFTCLVI
110 120 130 140 150
LFACEVAAGI WGFVNKDQIA KDVKQFYDQA LQQAVVDDDA NNAKAVVKTF
160 170 180 190 200
HETLDCCGSS TLAALTTSVL KNNLCPSGSN IISNLLKKDC HQKIDELFSG
210 220 230
KLYLIGIAAI VVAVIMIFEM ILSMVLCCGI RNSSVY
Length:236
Mass (Da):25,758
Last modified:May 1, 1999 - v1
<p>The checksum is a form of redundancy check that is calculated from the sequence. It is useful for tracking sequence updates.</p> <p>It should be noted that while, in theory, two different sequences could have the same checksum value, the likelihood that this would happen is extremely low.</p> <p>However UniProtKB may contain entries with identical sequences in case of multiple genes (paralogs).</p> <p>The checksum is computed as the sequence 64-bit Cyclic Redundancy Check value (CRC64) using the generator polynomial: x<sup>64</sup> + x<sup>4</sup> + x<sup>3</sup> + x + 1. The algorithm is described in the ISO 3309 standard. </p> <p class="publication">Press W.H., Flannery B.P., Teukolsky S.A. and Vetterling W.T.<br /> <strong>Cyclic redundancy and other checksums</strong><br /> <a href="http://www.nrbook.com/b/bookcpdf.php">Numerical recipes in C 2nd ed., pp896-902, Cambridge University Press (1993)</a>)</p> Checksum:iE07A8EC2C7637A4A
GO

Sequence databases

Select the link destinations:

EMBL nucleotide sequence database

More...
EMBLi

GenBank nucleotide sequence database

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GenBanki

DNA Data Bank of Japan; a nucleotide sequence database

More...
DDBJi
Links Updated
AF116599 mRNA Translation: AAD11439.1

<p>This section provides links to proteins that are similar to the protein sequence(s) described in this entry at different levels of sequence identity thresholds (100%, 90% and 50%) based on their membership in UniProt Reference Clusters (<a href="http://www.uniprot.org/help/uniref">UniRef</a>).<p><a href='/help/similar_proteins_section' target='_top'>More...</a></p>Similar proteinsi

<p>This section is used to point to information related to entries and found in data collections other than UniProtKB.<p><a href='/help/cross_references_section' target='_top'>More...</a></p>Cross-referencesi

Sequence databases

Select the link destinations:
EMBLi
GenBanki
DDBJi
Links Updated
AF116599 mRNA Translation: AAD11439.1

3D structure databases

SMRiO97703
ModBaseiSearch...

Family and domain databases

Gene3Di1.10.1450.10, 1 hit
InterProiView protein in InterPro
IPR000301 Tetraspanin
IPR018499 Tetraspanin/Peripherin
IPR018503 Tetraspanin_CS
IPR008952 Tetraspanin_EC2_sf
PfamiView protein in Pfam
PF00335 Tetraspanin, 1 hit
PIRSFiPIRSF002419 Tetraspanin, 1 hit
PRINTSiPR00259 TMFOUR
SUPFAMiSSF48652 SSF48652, 1 hit
PROSITEiView protein in PROSITE
PS00421 TM4_1, 1 hit

ProtoNet; Automatic hierarchical classification of proteins

More...
ProtoNeti
Search...

MobiDB: a database of protein disorder and mobility annotations

More...
MobiDBi
Search...

<p>This section provides general information on the entry.<p><a href='/help/entry_information_section' target='_top'>More...</a></p>Entry informationi

<p>This subsection of the ‘Entry information’ section provides a mnemonic identifier for a UniProtKB entry, but it is not a stable identifier. Each reviewed entry is assigned a unique entry name upon integration into UniProtKB/Swiss-Prot.<p><a href='/help/entry_name' target='_top'>More...</a></p>Entry nameiCD81_CHLAE
<p>This subsection of the ‘Entry information’ section provides one or more accession number(s). These are stable identifiers and should be used to cite UniProtKB entries. Upon integration into UniProtKB, each entry is assigned a unique accession number, which is called ‘Primary (citable) accession number’.<p><a href='/help/accession_numbers' target='_top'>More...</a></p>AccessioniPrimary (citable) accession number: O97703
<p>This subsection of the ‘Entry information’ section shows the date of integration of the entry into UniProtKB, the date of the last sequence update and the date of the last annotation modification (‘Last modified’). The version number for both the entry and the <a href="http://www.uniprot.org/help/canonical_and_isoforms">canonical sequence</a> are also displayed.<p><a href='/help/entry_history' target='_top'>More...</a></p>Entry historyiIntegrated into UniProtKB/Swiss-Prot: December 1, 2000
Last sequence update: May 1, 1999
Last modified: May 8, 2019
This is version 88 of the entry and version 1 of the sequence. See complete history.
<p>This subsection of the ‘Entry information’ section indicates whether the entry has been manually annotated and reviewed by UniProtKB curators or not, in other words, if the entry belongs to the Swiss-Prot section of UniProtKB (<strong>reviewed</strong>) or to the computer-annotated TrEMBL section (<strong>unreviewed</strong>).<p><a href='/help/entry_status' target='_top'>More...</a></p>Entry statusiReviewed (UniProtKB/Swiss-Prot)
Annotation programChordata Protein Annotation Program

<p>This section contains any relevant information that doesn’t fit in any other defined sections<p><a href='/help/miscellaneous_section' target='_top'>More...</a></p>Miscellaneousi

Documents

  1. SIMILARITY comments
    Index of protein domains and families
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