Skip Header

You are using a version of browser that may not display all the features of this website. Please consider upgrading your browser.

UniProtKB - P20023 (CR2_HUMAN)

Entry version 209 (12 Aug 2020)
Sequence version 2 (25 Nov 2008)
Previous versions | rss
Help videoAdd a publicationFeedback
Protein

Complement receptor type 2

Gene

CR2

Organism
Homo sapiens (Human)
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 protein 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

Receptor for complement C3, for the Epstein-Barr virus on human B-cells and T-cells and for HNRNPU (PubMed:7753047). Participates in B lymphocytes activation (PubMed:7753047).1 Publication
(Microbial infection) Acts as a receptor for Epstein-Barr virus.1 Publication

<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

Complete GO annotation on QuickGO ...

GO - Biological processi

Complete GO annotation on QuickGO ...

<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

Molecular functionHost cell receptor for virus entry, Receptor
Biological processComplement pathway, Host-virus interaction, Immunity, Innate immunity

Enzyme and pathway databases

Pathway Commons web resource for biological pathway data

More...PathwayCommonsi		P20023

Reactome - a knowledgebase of biological pathways and processes

More...Reactomei		R-HSA-977606, Regulation of Complement cascade

SIGNOR Signaling Network Open Resource

More...SIGNORi		P20023

<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%5Fand%5Ftaxonomy%5Fsection">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:
Complement receptor type 2
Short name:
Cr2
Alternative name(s):
Complement C3d receptor
Epstein-Barr virus receptor
Short name:
EBV receptor
CD_antigen: CD21
<p>This subsection of the <a href="http://www.uniprot.org/help/names%5Fand%5Ftaxonomy%5Fsection">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:CR2
Synonyms:C3DR
<p>This subsection of the <a href="http://www.uniprot.org/help/names%5Fand%5Ftaxonomy%5Fsection">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>OrganismiHomo sapiens (Human)
<p>This subsection of the <a href="http://www.uniprot.org/help/names%5Fand%5Ftaxonomy%5Fsection">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 identifieri9606 [NCBI]
<p>This subsection of the <a href="http://www.uniprot.org/help/names%5Fand%5Ftaxonomy%5Fsection">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 lineageiEukaryota › Metazoa › Chordata › Craniata › Vertebrata › Euteleostomi › Mammalia › Eutheria › Euarchontoglires › Primates › Haplorrhini › Catarrhini › Hominidae › Homo
<p>This subsection of the <a href="http://www.uniprot.org/help/names%5Fand%5Ftaxonomy%5Fsection">Names and taxonomy</a> section is present for entries that are part of a <a href="http://www.uniprot.org/proteomes">proteome</a>, i.e. of a set of proteins thought to be expressed by organisms whose genomes have been completely sequenced.<p><a href='/help/proteomes_manual' target='_top'>More...</a></p>Proteomesi
  • UP000005640 <p>A UniProt <a href="http://www.uniprot.org/manual/proteomes%5Fmanual">proteome</a> can consist of several components.<br></br>The component name refers to the genomic component encoding a set of proteins.<p><a href='/help/proteome_component' target='_top'>More...</a></p> Componenti: Chromosome 1

Organism-specific databases

Eukaryotic Pathogen Database Resources

More...EuPathDBi		HostDB:ENSG00000117322.16

Human Gene Nomenclature Database

More...HGNCi		HGNC:2336, CR2

Online Mendelian Inheritance in Man (OMIM)

More...MIMi		120650, gene

neXtProt; the human protein knowledge platform

More...neXtProti		NX_P20023

<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%5Flocation%5Fsection">'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 domaini21 – 971ExtracellularSequence analysisAdd BLAST951
<p>This subsection of the <a href="http://www.uniprot.org/help/subcellular%5Flocation%5Fsection">'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>Transmembranei972 – 999HelicalSequence analysisAdd BLAST28
Topological domaini1000 – 1033CytoplasmicSequence analysisAdd BLAST34

Keywords - Cellular componenti

Cell membrane, Membrane

<p>This section provides information on the disease(s) and phenotype(s) associated with a protein.<p><a href='/help/pathology_and_biotech_section' target='_top'>More...</a></p>Pathology & Biotechi

<p>This subsection of the 'Pathology and Biotech' section provides information on the disease(s) associated with genetic variations in a given protein. The information is extracted from the scientific literature and diseases that are also described in the <a href="http://www.ncbi.nlm.nih.gov/sites/entrez?db=omim">OMIM</a> database are represented with a <a href="http://www.uniprot.org/diseases">controlled vocabulary</a> in the following way:<p><a href='/help/involvement_in_disease' target='_top'>More...</a></p>Involvement in diseasei

Systemic lupus erythematosus 9 (SLEB9)1 Publication
Disease susceptibility is associated with variations affecting the gene represented in this entry.
Disease descriptionA chronic, relapsing, inflammatory, and often febrile multisystemic disorder of connective tissue, characterized principally by involvement of the skin, joints, kidneys and serosal membranes. It is of unknown etiology, but is thought to represent a failure of the regulatory mechanisms of the autoimmune system. The disease is marked by a wide range of system dysfunctions, an elevated erythrocyte sedimentation rate, and the formation of LE cells in the blood or bone marrow.
Related information in OMIM
Immunodeficiency, common variable, 7 (CVID7)1 Publication
The disease is caused by mutations affecting the gene represented in this entry.
Disease descriptionA primary immunodeficiency characterized by antibody deficiency, hypogammaglobulinemia, recurrent bacterial infections and an inability to mount an antibody response to antigen. The defect results from a failure of B-cell differentiation and impaired secretion of immunoglobulins; the numbers of circulating B-cells is usually in the normal range, but can be low.
Related information in OMIM

Mutagenesis

Feature keyPosition(s)DescriptionActionsGraphical viewLength
<p>This subsection of the <a href="http://www.uniprot.org/manual/pathology%5Fand%5Fbiotech%5Fsection">'Pathology and Biotech'</a> section describes the effect of the experimental mutation of one or more amino acid(s) on the biological properties of the protein.<p><a href='/help/mutagen' target='_top'>More...</a></p>Mutagenesisi103R → A: No effect on affinity for C3. 1 Publication1
Mutagenesisi112D → A: Reduced affinity for C3. 1 Publication1
Mutagenesisi128K → A: Strongly reduced affinity for C3. 1 Publication1

Keywords - Diseasei

Systemic lupus erythematosus

Organism-specific databases

DisGeNET

More...DisGeNETi		1380

MalaCards human disease database

More...MalaCardsi		CR2
MIMi610927, phenotype
614699, phenotype

Open Targets

More...OpenTargetsi		ENSG00000117322

Orphanet; a database dedicated to information on rare diseases and orphan drugs

More...Orphaneti		1572, Common variable immunodeficiency
536, Systemic lupus erythematosus

The Pharmacogenetics and Pharmacogenomics Knowledge Base

More...PharmGKBi		PA26857

Miscellaneous databases

Pharos NIH Druggable Genome Knowledgebase

More...Pharosi		P20023, Tbio

Polymorphism and mutation databases

BioMuta curated single-nucleotide variation and disease association database

More...BioMutai		CR2

Domain mapping of disease mutations (DMDM)

More...DMDMi		215273962

<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 denotes the presence of an N-terminal signal peptide.<p><a href='/help/signal' target='_top'>More...</a></p>Signal peptidei1 – 20Add BLAST20
<p>This subsection of the 'PTM / Processing' section describes the extent of a polypeptide chain in the mature protein following processing or proteolytic cleavage.<p><a href='/help/chain' target='_top'>More...</a></p>ChainiPRO_000000601021 – 1033Complement receptor type 2Add BLAST1013

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 bondi23 ↔ 65Combined sources3 Publications
Disulfide bondi51 ↔ 82Combined sources3 Publications
Disulfide bondi91 ↔ 132Combined sources3 Publications
Disulfide bondi118 ↔ 146Combined sources3 Publications
<p>This subsection of the <a href="http://www.uniprot.org/help/ptm%5Fprocessing%5Fsection">PTM / Processing</a> section specifies the position and type of each covalently attached glycan group (mono-, di-, or polysaccharide).<p><a href='/help/carbohyd' target='_top'>More...</a></p>Glycosylationi121N-linked (GlcNAc...) asparagineCombined sources1 Publication1
Glycosylationi127N-linked (GlcNAc...) asparagineCombined sources1 Publication1
Disulfide bondi154 ↔ 197PROSITE-ProRule annotation
Disulfide bondi183 ↔ 210PROSITE-ProRule annotation
Disulfide bondi215 ↔ 256PROSITE-ProRule annotation
Disulfide bondi242 ↔ 271PROSITE-ProRule annotation
Disulfide bondi276 ↔ 325PROSITE-ProRule annotation
Glycosylationi294N-linked (GlcNAc...) asparagineSequence analysis1
Disulfide bondi305 ↔ 342PROSITE-ProRule annotation
Disulfide bondi351 ↔ 393PROSITE-ProRule annotation
Glycosylationi372N-linked (GlcNAc...) asparagineSequence analysis1
Disulfide bondi379 ↔ 406PROSITE-ProRule annotation
Disulfide bondi410 ↔ 453PROSITE-ProRule annotation
Disulfide bondi439 ↔ 466PROSITE-ProRule annotation
Disulfide bondi471 ↔ 509PROSITE-ProRule annotation
Glycosylationi492N-linked (GlcNAc...) asparagineSequence analysis1
Disulfide bondi495 ↔ 522PROSITE-ProRule annotation
Disulfide bondi527 ↔ 576PROSITE-ProRule annotation
Disulfide bondi556 ↔ 593PROSITE-ProRule annotation
Disulfide bondi602 ↔ 644PROSITE-ProRule annotation
Glycosylationi623N-linked (GlcNAc...) asparagine1 Publication1
Disulfide bondi630 ↔ 657PROSITE-ProRule annotation
Disulfide bondi662 ↔ 699PROSITE-ProRule annotation
Glycosylationi682N-linked (GlcNAc...) asparagineSequence analysis1
Disulfide bondi685 ↔ 714PROSITE-ProRule annotation
Disulfide bondi719 ↔ 762PROSITE-ProRule annotation
Disulfide bondi748 ↔ 779PROSITE-ProRule annotation
Disulfide bondi788 ↔ 830PROSITE-ProRule annotation
Glycosylationi800N-linked (GlcNAc...) asparagineSequence analysis1
Disulfide bondi816 ↔ 843PROSITE-ProRule annotation
Glycosylationi823N-linked (GlcNAc...) asparagineSequence analysis1
Disulfide bondi851 ↔ 894PROSITE-ProRule annotation
Glycosylationi861N-linked (GlcNAc...) asparagineSequence analysis1
Disulfide bondi880 ↔ 907PROSITE-ProRule annotation
Glycosylationi911N-linked (GlcNAc...) asparagineSequence analysis1
Disulfide bondi912 ↔ 955PROSITE-ProRule annotation
Disulfide bondi941 ↔ 968PROSITE-ProRule annotation

Keywords - PTMi

Disulfide bond, Glycoprotein

Proteomic databases

MassIVE - Mass Spectrometry Interactive Virtual Environment

More...MassIVEi		P20023

PeptideAtlas

More...PeptideAtlasi		P20023

PRoteomics IDEntifications database

More...PRIDEi		P20023

ProteomicsDB: a multi-organism proteome resource

More...ProteomicsDBi		53712 [P20023-1]
53713 [P20023-2]
53714 [P20023-3]
53715 [P20023-4]

PTM databases

GlyGen: Computational and Informatics Resources for Glycoscience

More...GlyGeni		P20023, 13 sites

iPTMnet integrated resource for PTMs in systems biology context

More...iPTMneti		P20023

Comprehensive resource for the study of protein post-translational modifications (PTMs) in human, mouse and rat.

More...PhosphoSitePlusi		P20023

<p>This section provides information on the expression of a gene at the mRNA or protein level in cells or in tissues of multicellular organisms.<p><a href='/help/expression_section' target='_top'>More...</a></p>Expressioni

<p>This subsection of the 'Expression' section provides information on the expression of a gene at the mRNA or protein level in cells or in tissues of multicellular organisms. By default, the information is derived from experiments at the mRNA level, unless specified 'at protein level'.<br></br>Examples: <a href="http://www.uniprot.org/uniprot/P92958#expression">P92958</a>, <a href="http://www.uniprot.org/uniprot/Q8TDN4#expression">Q8TDN4</a>, <a href="http://www.uniprot.org/uniprot/O14734#expression">O14734</a><p><a href='/help/tissue_specificity' target='_top'>More...</a></p>Tissue specificityi

Mature B-lymphocytes, T-lymphocytes, pharyngeal epithelial cells, astrocytes and follicular dendritic cells of the spleen.

Gene expression databases

Bgee dataBase for Gene Expression Evolution

More...Bgeei		ENSG00000117322, Expressed in tonsil and 110 other tissues

ExpressionAtlas, Differential and Baseline Expression

More...ExpressionAtlasi		P20023, baseline and differential

Genevisible search portal to normalized and curated expression data from Genevestigator

More...Genevisiblei		P20023, HS

Organism-specific databases

Human Protein Atlas

More...HPAi		ENSG00000117322, Tissue enriched (lymphoid)

<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%5Fsection">'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%5Fsection">'Function'</a> section).<p><a href='/help/subunit_structure' target='_top'>More...</a></p>Subunit structurei

Interacts (via Sushi domain 1 and 2) with C3 (PubMed:11387479, PubMed:21527715).

Interacts with CD19 (PubMed:1702139).

Part of a complex composed of CD19, CR2/CD21, CD81 and IFITM1/CD225 in the membrane of mature B-cells (PubMed:1383329).

4 Publications

(Microbial infection) Interacts with Epstein-Barr virus gp350 protein.

1 Publication

GO - Molecular functioni

Complete GO annotation on QuickGO ...

Protein-protein interaction databases

The Biological General Repository for Interaction Datasets (BioGRID)

More...BioGRIDi		107771, 7 interactors

CORUM comprehensive resource of mammalian protein complexes

More...CORUMi		P20023

Protein interaction database and analysis system

More...IntActi		P20023, 1 interactor

STRING: functional protein association networks

More...STRINGi		9606.ENSP00000356024

Miscellaneous databases

RNAct, Protein-RNA interaction predictions for model organisms.

More...RNActi		P20023, protein

<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

Secondary structure

11033
Legend: HelixTurnBeta strandPDB Structure known for this area
Show more details

3D structure databases

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

More...SMRi		P20023

Database of comparative protein structure models

More...ModBasei		Search...

Protein Data Bank in Europe - Knowledge Base

More...PDBe-KBi		Search...

Miscellaneous databases

Relative evolutionary importance of amino acids within a protein sequence

More...EvolutionaryTracei		P20023

<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

Domains and Repeats

Feature keyPosition(s)DescriptionActionsGraphical viewLength
<p>This subsection of the <a href="http://www.uniprot.org/help/family%5Fand%5Fdomains%5Fsection">Family and Domains</a> section describes the position and type of a domain, which is defined as a specific combination of secondary structures organized into a characteristic three-dimensional structure or fold.<p><a href='/help/domain' target='_top'>More...</a></p>Domaini21 – 84Sushi 1PROSITE-ProRule annotationAdd BLAST64
Domaini89 – 148Sushi 2PROSITE-ProRule annotationAdd BLAST60
Domaini152 – 212Sushi 3PROSITE-ProRule annotationAdd BLAST61
Domaini213 – 273Sushi 4PROSITE-ProRule annotationAdd BLAST61
Domaini274 – 344Sushi 5PROSITE-ProRule annotationAdd BLAST71
Domaini349 – 408Sushi 6PROSITE-ProRule annotationAdd BLAST60
Domaini409 – 468Sushi 7PROSITE-ProRule annotationAdd BLAST60
Domaini469 – 524Sushi 8PROSITE-ProRule annotationAdd BLAST56
Domaini525 – 595Sushi 9PROSITE-ProRule annotationAdd BLAST71
Domaini600 – 659Sushi 10PROSITE-ProRule annotationAdd BLAST60
Domaini660 – 716Sushi 11PROSITE-ProRule annotationAdd BLAST57
Domaini717 – 781Sushi 12PROSITE-ProRule annotationAdd BLAST65
Domaini786 – 845Sushi 13PROSITE-ProRule annotationAdd BLAST60
Domaini849 – 909Sushi 14PROSITE-ProRule annotationAdd BLAST61
Domaini910 – 970Sushi 15PROSITE-ProRule annotationAdd BLAST61

<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 receptors of complement activation (RCA) family.Curated

Keywords - Domaini

Repeat, Signal, Sushi, Transmembrane, Transmembrane helix

Phylogenomic databases

evolutionary genealogy of genes: Non-supervised Orthologous Groups

More...eggNOGi		KOG4297, Eukaryota

Ensembl GeneTree

More...GeneTreei		ENSGT00940000161110

The HOGENOM Database of Homologous Genes from Fully Sequenced Organisms

More...HOGENOMi		CLU_005124_0_0_1

InParanoid: Eukaryotic Ortholog Groups

More...InParanoidi		P20023

KEGG Orthology (KO)

More...KOi		K04012

Identification of Orthologs from Complete Genome Data

More...OMAi		KVAECEP

Database of Orthologous Groups

More...OrthoDBi		702827at2759

Database for complete collections of gene phylogenies

More...PhylomeDBi		P20023

TreeFam database of animal gene trees

More...TreeFami		TF316872

Family and domain databases

Conserved Domains Database

More...CDDi		cd00033, CCP, 13 hits

Integrated resource of protein families, domains and functional sites

More...InterProi		View protein in InterPro
IPR035976, Sushi/SCR/CCP_sf
IPR000436, Sushi_SCR_CCP_dom

Pfam protein domain database

More...Pfami		View protein in Pfam
PF00084, Sushi, 13 hits

Simple Modular Architecture Research Tool; a protein domain database

More...SMARTi		View protein in SMART
SM00032, CCP, 14 hits

Superfamily database of structural and functional annotation

More...SUPFAMi		SSF57535, SSF57535, 15 hits

PROSITE; a protein domain and family database

More...PROSITEi		View protein in PROSITE
PS50923, SUSHI, 15 hits

<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%5Flength">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>Sequences (4+)i

<p>This subsection of the <a href="http://www.uniprot.org/help/sequences%5Fsection">Sequence</a> section indicates if the <a href="http://www.uniprot.org/help/canonical%5Fand%5Fisoforms">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.

<p>This subsection of the <a href="http://www.uniprot.org/help/sequences%5Fsection">Sequence</a> section indicates if the <a href="http://www.uniprot.org/help/canonical%5Fand%5Fisoforms">canonical sequence</a> displayed by default in the entry is in its mature form or if it represents the precursor.<p><a href='/help/sequence_processing' target='_top'>More...</a></p>Sequence processingi: The displayed sequence is further processed into a mature form.

This entry describes 4 <p>This subsection of the 'Sequence' section lists the alternative protein sequences (isoforms) that can be generated from the same gene by a single or by the combination of up to four biological events (alternative promoter usage, alternative splicing, alternative initiation and ribosomal frameshifting). Additionally, this section gives relevant information on each alternative protein isoform. This section is only present in reviewed entries, i.e. in UniProtKB/Swiss-Prot.<p><a href='/help/alternative_products' target='_top'>More...</a></p> isoformsi produced by alternative splicing. AlignAdd to basket

This entry has 4 described isoforms and 2 potential isoforms that are computationally mapped.Show allAlign All

Isoform A (identifier: P20023-1) [UniParc]FASTAAdd to basket

This isoform has been chosen as the <div> <p><b>What is the canonical sequence?</b><p><a href='/help/canonical_and_isoforms' target='_top'>More...</a></p>canonicali sequence. All positional information in this entry refers to it. This is also the sequence that appears in the downloadable versions of the entry.

« Hide
        10         20         30         40         50
MGAAGLLGVF LALVAPGVLG ISCGSPPPIL NGRISYYSTP IAVGTVIRYS 
        60         70         80         90        100
CSGTFRLIGE KSLLCITKDK VDGTWDKPAP KCEYFNKYSS CPEPIVPGGY 
       110        120        130        140        150
KIRGSTPYRH GDSVTFACKT NFSMNGNKSV WCQANNMWGP TRLPTCVSVF 
       160        170        180        190        200
PLECPALPMI HNGHHTSENV GSIAPGLSVT YSCESGYLLV GEKIINCLSS 
       210        220        230        240        250
GKWSAVPPTC EEARCKSLGR FPNGKVKEPP ILRVGVTANF FCDEGYRLQG 
       260        270        280        290        300
PPSSRCVIAG QGVAWTKMPV CEEIFCPSPP PILNGRHIGN SLANVSYGSI 
       310        320        330        340        350
VTYTCDPDPE EGVNFILIGE STLRCTVDSQ KTGTWSGPAP RCELSTSAVQ 
       360        370        380        390        400
CPHPQILRGR MVSGQKDRYT YNDTVIFACM FGFTLKGSKQ IRCNAQGTWE 
       410        420        430        440        450
PSAPVCEKEC QAPPNILNGQ KEDRHMVRFD PGTSIKYSCN PGYVLVGEES 
       460        470        480        490        500
IQCTSEGVWT PPVPQCKVAA CEATGRQLLT KPQHQFVRPD VNSSCGEGYK 
       510        520        530        540        550
LSGSVYQECQ GTIPWFMEIR LCKEITCPPP PVIYNGAHTG SSLEDFPYGT 
       560        570        580        590        600
TVTYTCNPGP ERGVEFSLIG ESTIRCTSND QERGTWSGPA PLCKLSLLAV 
       610        620        630        640        650
QCSHVHIANG YKISGKEAPY FYNDTVTFKC YSGFTLKGSS QIRCKADNTW 
       660        670        680        690        700
DPEIPVCEKE TCQHVRQSLQ ELPAGSRVEL VNTSCQDGYQ LTGHAYQMCQ 
       710        720        730        740        750
DAENGIWFKK IPLCKVIHCH PPPVIVNGKH TGMMAENFLY GNEVSYECDQ 
       760        770        780        790        800
GFYLLGEKKL QCRSDSKGHG SWSGPSPQCL RSPPVTRCPN PEVKHGYKLN 
       810        820        830        840        850
KTHSAYSHND IVYVDCNPGF IMNGSRVIRC HTDNTWVPGV PTCIKKAFIG 
       860        870        880        890        900
CPPPPKTPNG NHTGGNIARF SPGMSILYSC DQGYLLVGEA LLLCTHEGTW 
       910        920        930        940        950
SQPAPHCKEV NCSSPADMDG IQKGLEPRKM YQYGAVVTLE CEDGYMLEGS 
       960        970        980        990       1000
PQSQCQSDHQ WNPPLAVCRS RSLAPVLCGI AAGLILLTFL IVITLYVISK 
      1010       1020       1030 
HRARNYYTDT SQKEAFHLEA REVYSVDPYN PAS
Length:1,033
Mass (Da):112,916
Last modified:November 25, 2008 - v2
<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:i7D89DB4A07847E9A
GO
Isoform B (identifier: P20023-2) [UniParc]FASTAAdd to basket

The sequence of this isoform differs from the canonical sequence as follows:
     499-524: Missing.
     525-556: ITCPPPPVIYNGAHTGSSLEDFPYGTTVTYTC → NHLPTTPCYLQWGTHREFLRRFSIWNHGHLHM

Show »
Length:1,007
Mass (Da):110,408
Checksum:iBA75D3B0A8EB5511
GO
Isoform C (identifier: P20023-3) [UniParc]FASTAAdd to basket

The sequence of this isoform differs from the canonical sequence as follows:
     659-659: K → KGCQSPPGLHHGRHTGGNTVFFVSGMTVDYTCDPGYLLVGNKSIHCMPSGNWSPSAPRCE

Show »
Length:1,092
Mass (Da):119,160
Checksum:iA52592EB53DE7374
GO
Isoform D (identifier: P20023-4) [UniParc]FASTAAdd to basket

The sequence of this isoform differs from the canonical sequence as follows:
     659-659: K → KGCQSPPGLHHGRHTGGNTVFFVSGMTVDYTCDPGYLLVGNKSIHCMPSGNWSPSAPRCE
     716-723: Missing.

Show »
Length:1,084
Mass (Da):118,279
Checksum:i9C232F47D384E59B
GO

<p>In eukaryotic reference proteomes, unreviewed entries that are likely to belong to the same gene are computationally mapped, based on gene identifiers from Ensembl, EnsemblGenomes and model organism databases.<p><a href='/help/gene_centric_isoform_mapping' target='_top'>More...</a></p>Computationally mapped potential isoform sequencesi

There are 2 potential isoforms mapped to this entry.BLASTAlignShow allAdd to basket
EntryEntry nameProtein names
Gene namesLengthAnnotation
Q5SR47Q5SR47_HUMAN
Complement receptor type 2
CR2
971Annotation score:

Annotation score:2 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>
A0A1W2PPV2A0A1W2PPV2_HUMAN
Complement receptor type 2
CR2
39Annotation score:

Annotation score:1 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>

<p>This subsection of the 'Sequence' section reports difference(s) between the protein sequence shown in the UniProtKB entry and other available protein sequences derived from the same gene.<p><a href='/help/sequence_caution' target='_top'>More...</a></p>Sequence cautioni

The sequence AAA35784 differs from that shown. Reason: Frameshift.Curated

Experimental Info

Feature keyPosition(s)DescriptionActionsGraphical viewLength
<p>This subsection of the 'Sequence' section reports difference(s) between the canonical sequence (displayed by default in the entry) and the different sequence submissions merged in the entry. These various submissions may originate from different sequencing projects, different types of experiments, or different biological samples. Sequence conflicts are usually of unknown origin.<p><a href='/help/conflict' target='_top'>More...</a></p>Sequence conflicti457Missing in CAA68674 (PubMed:2832506).Curated1
Sequence conflicti646A → R in AAA35784 (PubMed:2827171).Curated1
Sequence conflicti667Q → D AA sequence (PubMed:3016712).Curated1
Sequence conflicti774G → E in AAA35784 (PubMed:2827171).Curated1
Sequence conflicti783 – 787PPVTR → L in AAA35784 (PubMed:2827171).Curated5
Sequence conflicti844I → M in AAA35786 (PubMed:2563370).Curated1
Sequence conflicti844I → M in AAB04638 (PubMed:2563370).Curated1
Sequence conflicti886L → V in AAA35784 (PubMed:2827171).Curated1
Sequence conflicti890A → P in AAA35784 (PubMed:2827171).Curated1
Sequence conflicti902Q → G AA sequence (PubMed:3016712).Curated1
Sequence conflicti906H → L AA sequence (PubMed:3016712).Curated1
Isoform C (identifier: P20023-3)
Sequence conflicti663S → P in AAA35784 (PubMed:2827171).Curated1

Natural variant

Feature keyPosition(s)DescriptionActionsGraphical viewLength
<p>This subsection of the 'Sequence' section describes natural variant(s) of the protein sequence.<p><a href='/help/variant' target='_top'>More...</a></p>Natural variantiVAR_016164639S → N2 PublicationsCorresponds to variant dbSNP:rs17615EnsemblClinVar.1
Natural variantiVAR_016165993I → V1 PublicationCorresponds to variant dbSNP:rs17618Ensembl.1
Natural variantiVAR_0161661003A → E2 PublicationsCorresponds to variant dbSNP:rs17617Ensembl.1

Alternative sequence

Feature keyPosition(s)DescriptionActionsGraphical viewLength
<p>This subsection of the 'Sequence' section describes the sequence of naturally occurring alternative protein isoform(s). The changes in the amino acid sequence may be due to alternative splicing, alternative promoter usage, alternative initiation, or ribosomal frameshifting.<p><a href='/help/var_seq' target='_top'>More...</a></p>Alternative sequenceiVSP_001208499 – 524Missing in isoform B. 1 PublicationAdd BLAST26
Alternative sequenceiVSP_001209525 – 556ITCPP…VTYTC → NHLPTTPCYLQWGTHREFLR RFSIWNHGHLHM in isoform B. 1 PublicationAdd BLAST32
Alternative sequenceiVSP_001210659K → KGCQSPPGLHHGRHTGGNTV FFVSGMTVDYTCDPGYLLVG NKSIHCMPSGNWSPSAPRCE in isoform C and isoform D. 5 Publications1
Alternative sequenceiVSP_001211716 – 723Missing in isoform D. 1 Publication8

Sequence databases

Select the link destinations:

EMBL nucleotide sequence database

More...EMBLi

GenBank nucleotide sequence database

More...GenBanki

DNA Data Bank of Japan; a nucleotide sequence database

More...DDBJi
Links Updated
M26004 mRNA Translation: AAA35786.1
M26016 M26015 Genomic DNA Translation: AAB04638.1
Y00649 mRNA Translation: CAA68674.1
J03565 mRNA Translation: AAA35784.1 Frameshift.
AK223627 mRNA Translation: BAD97347.1
AK301496 mRNA Translation: BAG63007.1
EF064746 Genomic DNA Translation: ABK41929.1
AL391597 Genomic DNA No translation available.
AL691452 Genomic DNA No translation available.
BC090937 mRNA Translation: AAH90937.1
BC136394 mRNA Translation: AAI36395.1
S62696 mRNA Translation: AAB27186.1

The Consensus CDS (CCDS) project

More...CCDSi		CCDS1478.1 [P20023-1]
CCDS31007.1 [P20023-3]

Protein sequence database of the Protein Information Resource

More...PIRi		JL0028, PL0009

NCBI Reference Sequences

More...RefSeqi		NP_001006659.1, NM_001006658.2 [P20023-3]
NP_001868.2, NM_001877.4 [P20023-1]

Genome annotation databases

Ensembl eukaryotic genome annotation project

More...Ensembli		ENST00000367057; ENSP00000356024; ENSG00000117322 [P20023-3]
ENST00000367058; ENSP00000356025; ENSG00000117322 [P20023-1]

Database of genes from NCBI RefSeq genomes

More...GeneIDi		1380

KEGG: Kyoto Encyclopedia of Genes and Genomes

More...KEGGi		hsa:1380

UCSC genome browser

More...UCSCi		uc001hfv.4, human [P20023-1]

Keywords - Coding sequence diversityi

Alternative splicing, Polymorphism

<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
M26004 mRNA Translation: AAA35786.1
M26016 M26015 Genomic DNA Translation: AAB04638.1
Y00649 mRNA Translation: CAA68674.1
J03565 mRNA Translation: AAA35784.1 Frameshift.
AK223627 mRNA Translation: BAD97347.1
AK301496 mRNA Translation: BAG63007.1
EF064746 Genomic DNA Translation: ABK41929.1
AL391597 Genomic DNA No translation available.
AL691452 Genomic DNA No translation available.
BC090937 mRNA Translation: AAH90937.1
BC136394 mRNA Translation: AAI36395.1
S62696 mRNA Translation: AAB27186.1
CCDSiCCDS1478.1 [P20023-1]
CCDS31007.1 [P20023-3]
PIRiJL0028, PL0009
RefSeqiNP_001006659.1, NM_001006658.2 [P20023-3]
NP_001868.2, NM_001877.4 [P20023-1]

3D structure databases

Select the link destinations:

Protein Data Bank Europe

More...PDBei

Protein Data Bank RCSB

More...RCSB PDBi

Protein Data Bank Japan

More...PDBji
Links Updated
PDB entryMethodResolution (Å)ChainPositionsPDBsum
1GHQX-ray2.04B/C21-153[»]
1LY2X-ray1.80A22-148[»]
1W2RX-ray-A21-153[»]
1W2SX-ray-B21-153[»]
2ATYX-ray-A/B21-153[»]
2GSXX-ray-A21-971[»]
3OEDX-ray3.16C/D20-153[»]
SMRiP20023
ModBaseiSearch...
PDBe-KBiSearch...

Protein-protein interaction databases

BioGRIDi107771, 7 interactors
CORUMiP20023
IntActiP20023, 1 interactor
STRINGi9606.ENSP00000356024

PTM databases

GlyGeniP20023, 13 sites
iPTMnetiP20023
PhosphoSitePlusiP20023

Polymorphism and mutation databases

BioMutaiCR2
DMDMi215273962

Proteomic databases

MassIVEiP20023
PeptideAtlasiP20023
PRIDEiP20023
ProteomicsDBi53712 [P20023-1]
53713 [P20023-2]
53714 [P20023-3]
53715 [P20023-4]

Protocols and materials databases

ABCD curated depository of sequenced antibodies

More...ABCDi		P20023, 1 sequenced antibody

Antibodypedia a portal for validated antibodies

More...Antibodypediai		3624, 1393 antibodies

Genome annotation databases

EnsembliENST00000367057; ENSP00000356024; ENSG00000117322 [P20023-3]
ENST00000367058; ENSP00000356025; ENSG00000117322 [P20023-1]
GeneIDi1380
KEGGihsa:1380
UCSCiuc001hfv.4, human [P20023-1]

Organism-specific databases

Comparative Toxicogenomics Database

More...CTDi		1380
DisGeNETi1380
EuPathDBiHostDB:ENSG00000117322.16

GeneCards: human genes, protein and diseases

More...GeneCardsi		CR2
HGNCiHGNC:2336, CR2
HPAiENSG00000117322, Tissue enriched (lymphoid)
MalaCardsiCR2
MIMi120650, gene
610927, phenotype
614699, phenotype
neXtProtiNX_P20023
OpenTargetsiENSG00000117322
Orphaneti1572, Common variable immunodeficiency
536, Systemic lupus erythematosus
PharmGKBiPA26857

GenAtlas: human gene database

More...GenAtlasi		Search...

Phylogenomic databases

eggNOGiKOG4297, Eukaryota
GeneTreeiENSGT00940000161110
HOGENOMiCLU_005124_0_0_1
InParanoidiP20023
KOiK04012
OMAiKVAECEP
OrthoDBi702827at2759
PhylomeDBiP20023
TreeFamiTF316872

Enzyme and pathway databases

PathwayCommonsiP20023
ReactomeiR-HSA-977606, Regulation of Complement cascade
SIGNORiP20023

Miscellaneous databases

BioGRID ORCS database of CRISPR phenotype screens

More...BioGRID-ORCSi		1380, 2 hits in 869 CRISPR screens

ChiTaRS: a database of human, mouse and fruit fly chimeric transcripts and RNA-sequencing data

More...ChiTaRSi		CR2, human
EvolutionaryTraceiP20023

The Gene Wiki collection of pages on human genes and proteins

More...GeneWikii		Complement_receptor_2

Database of phenotypes from RNA interference screens in Drosophila and Homo sapiens

More...GenomeRNAii		1380
PharosiP20023, Tbio

Protein Ontology

More...PROi		PR:P20023
RNActiP20023, protein

The Stanford Online Universal Resource for Clones and ESTs

More...SOURCEi		Search...

Gene expression databases

BgeeiENSG00000117322, Expressed in tonsil and 110 other tissues
ExpressionAtlasiP20023, baseline and differential
GenevisibleiP20023, HS

Family and domain databases

CDDicd00033, CCP, 13 hits
InterProiView protein in InterPro
IPR035976, Sushi/SCR/CCP_sf
IPR000436, Sushi_SCR_CCP_dom
PfamiView protein in Pfam
PF00084, Sushi, 13 hits
SMARTiView protein in SMART
SM00032, CCP, 14 hits
SUPFAMiSSF57535, SSF57535, 15 hits
PROSITEiView protein in PROSITE
PS50923, SUSHI, 15 hits

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 nameiCR2_HUMAN
<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: P20023
Secondary accession number(s): C9JHD2
, Q13866, Q14212, Q53EL2, Q5BKT9, Q5SR46, Q5SR48
<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%5Fand%5Fisoforms">canonical sequence</a> are also displayed.<p><a href='/help/entry_history' target='_top'>More...</a></p>Entry historyiIntegrated into UniProtKB/Swiss-Prot: February 1, 1991
Last sequence update: November 25, 2008
Last modified: August 12, 2020
This is version 209 of the entry and version 2 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
DisclaimerAny medical or genetic information present in this entry is provided for research, educational and informational purposes only. It is not in any way intended to be used as a substitute for professional medical advice, diagnosis, treatment or care.

<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

Keywords - Technical termi

3D-structure, Direct protein sequencing, Reference proteome

Documents

  1. Human entries with polymorphisms or disease mutations
    List of human entries with polymorphisms or disease mutations
  2. Human polymorphisms and disease mutations
    Index of human polymorphisms and disease mutations
  3. MIM cross-references
    Online Mendelian Inheritance in Man (MIM) cross-references in UniProtKB/Swiss-Prot
  4. PDB cross-references
    Index of Protein Data Bank (PDB) cross-references
  5. SIMILARITY comments
    Index of protein domains and families
  6. Human chromosome 1
    Human chromosome 1: entries, gene names and cross-references to MIM
  7. Human cell differentiation molecules
    CD nomenclature of surface proteins of human leucocytes and list of entries
UniProt is an ELIXIR core data resource
Main funding by: National Institutes of Health

We'd like to inform you that we have updated our Privacy Notice to comply with Europe’s new General Data Protection Regulation (GDPR) that applies since 25 May 2018.

Do not show this banner again