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Protein

Immunoglobulin heavy constant alpha 2

Gene

IGHA2

Organism
Homo sapiens (Human)
Status
Reviewed-Annotation score: Annotation score: 5 out of 5-Experimental evidence at protein leveli

Functioni

Constant region of immunoglobulin heavy chains. Immunoglobulins, also known as antibodies, are membrane-bound or secreted glycoproteins produced by B lymphocytes. In the recognition phase of humoral immunity, the membrane-bound immunoglobulins serve as receptors which, upon binding of a specific antigen, trigger the clonal expansion and differentiation of B lymphocytes into immunoglobulins-secreting plasma cells. Secreted immunoglobulins mediate the effector phase of humoral immunity, which results in the elimination of bound antigens (PubMed:22158414, PubMed:20176268). The antigen binding site is formed by the variable domain of one heavy chain, together with that of its associated light chain. Thus, each immunoglobulin has two antigen binding sites with remarkable affinity for a particular antigen. The variable domains are assembled by a process called V-(D)-J rearrangement and can then be subjected to somatic hypermutations which, after exposure to antigen and selection, allow affinity maturation for a particular antigen (PubMed:17576170, PubMed:20176268). Ig alpha is the major immunoglobulin class in body secretions (PubMed:2241915).4 Publications

GO - Molecular functioni

  • antigen binding Source: UniProtKB

GO - Biological processi

  • antibacterial humoral response Source: UniProtKB
  • B cell receptor signaling pathway Source: GO_Central
  • complement activation, classical pathway Source: GO_Central
  • glomerular filtration Source: UniProtKB
  • immune response Source: UniProtKB
  • innate immune response Source: GO_Central
  • leukocyte migration Source: Reactome
  • phagocytosis, engulfment Source: GO_Central
  • phagocytosis, recognition Source: GO_Central
  • positive regulation of B cell activation Source: GO_Central
  • positive regulation of respiratory burst Source: UniProtKB
  • receptor-mediated endocytosis Source: Reactome
  • retina homeostasis Source: UniProtKB

Keywordsi

Biological processAdaptive immunity, Immunity

Enzyme and pathway databases

ReactomeiR-HSA-202733. Cell surface interactions at the vascular wall.
R-HSA-2168880. Scavenging of heme from plasma.

Protein family/group databases

IMGT/GENE-DBIGHA2.

Names & Taxonomyi

Protein namesi
Recommended name:
Immunoglobulin heavy constant alpha 22 Publications
Alternative name(s):
Ig alpha-2 chain C regionCurated
Ig alpha-2 chain C region BUT1 Publication
Ig alpha-2 chain C region LAN1 Publication
Gene namesi
Name:IGHA22 Publications
OrganismiHomo sapiens (Human)
Taxonomic identifieri9606 [NCBI]
Taxonomic lineageiEukaryotaMetazoaChordataCraniataVertebrataEuteleostomiMammaliaEutheriaEuarchontogliresPrimatesHaplorrhiniCatarrhiniHominidaeHomo
Proteomesi
  • UP000005640 Componenti: Chromosome 14

Organism-specific databases

HGNCiHGNC:5479. IGHA2.

Subcellular locationi

GO - Cellular componenti

  • blood microparticle Source: UniProtKB
  • external side of plasma membrane Source: GO_Central
  • extracellular exosome Source: UniProtKB
  • extracellular region Source: Reactome
  • extracellular space Source: UniProtKB
  • monomeric IgA immunoglobulin complex Source: UniProtKB
  • secretory dimeric IgA immunoglobulin complex Source: UniProtKB
  • secretory IgA immunoglobulin complex Source: UniProtKB

Keywords - Cellular componenti

Cell membrane, Membrane, Secreted

Pathology & Biotechi

Organism-specific databases

OpenTargetsiENSG00000211890.

Chemistry databases

DrugBankiDB04676. Dansyllysine.

Polymorphism and mutation databases

DMDMi218512088.

PTM / Processingi

Molecule processing

Feature keyPosition(s)DescriptionActionsGraphical viewLength
ChainiPRO_0000153567‹1 – 340Immunoglobulin heavy constant alpha 2Add BLAST›340

Amino acid modifications

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Disulfide bondi26 ↔ 85PROSITE-ProRule annotation
Glycosylationi47N-linked (GlcNAc...) asparagine1 Publication1
Glycosylationi92N-linked (GlcNAc...) (complex) asparagine2 Publications1
Disulfide bondi101Interchain (with light chain)
Disulfide bondi109Interchain (with heavy chain)
Disulfide bondi110 ↔ 167
Glycosylationi131N-linked (GlcNAc...) asparagine2 Publications1
Disulfide bondi134 ↔ 191PROSITE-ProRule annotation
Disulfide bondi169Interchain (with heavy chain)
Disulfide bondi179Interchain (with heavy chain of another subunit)
Glycosylationi205N-linked (GlcNAc...) (complex) asparagine5 Publications1
Disulfide bondi237 ↔ 300PROSITE-ProRule annotation
Glycosylationi327N-linked (GlcNAc...) (complex) asparagine3 Publications1
Disulfide bondi339Interchain (with J chain)

Keywords - PTMi

Disulfide bond, Glycoprotein

Proteomic databases

PeptideAtlasiP01877.
PRIDEiP01877.

PTM databases

iPTMnetiP01877.
PhosphoSitePlusiP01877.
UniCarbKBiP01877.

Expressioni

Gene expression databases

BgeeiENSG00000211890.

Interactioni

Subunit structurei

Immunoglobulins are composed of two identical heavy chains and two identical light chains; disulfide-linked (PubMed:20176268). Monomeric or polymeric (PubMed:2241915).2 Publications

Protein-protein interaction databases

IntActiP01877. 19 interactors.

Structurei

3D structure databases

Select the link destinations:
PDBei
RCSB PDBi
PDBji
Links Updated
PDB entryMethodResolution (Å)ChainPositionsPDBsum
3CM9X-ray-A/B/C/D2-340[»]
ProteinModelPortaliP01877.
SMRiP01877.
ModBaseiSearch...
MobiDBiSearch...

Family & Domainsi

Domains and Repeats

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Domaini6 – 98Ig-like 1PROSITE-ProRule annotationAdd BLAST93
Domaini112 – 207Ig-like 2PROSITE-ProRule annotationAdd BLAST96
Domaini215 – 317Ig-like 3PROSITE-ProRule annotationAdd BLAST103

Keywords - Domaini

Immunoglobulin C region, Immunoglobulin domain, Repeat

Phylogenomic databases

GeneTreeiENSGT00530000063726.
HOVERGENiHBG005814.
InParanoidiP01877.
OMAiKPTHINV.
PhylomeDBiP01877.

Family and domain databases

Gene3Di2.60.40.10. 3 hits.
InterProiView protein in InterPro
IPR007110. Ig-like_dom.
IPR013783. Ig-like_fold.
IPR003006. Ig/MHC_CS.
IPR003597. Ig_C1-set.
IPR013151. Immunoglobulin.
PfamiView protein in Pfam
PF07654. C1-set. 2 hits.
PF00047. ig. 1 hit.
SMARTiView protein in SMART
SM00407. IGc1. 3 hits.
SUPFAMiSSF48726. SSF48726. 3 hits.
PROSITEiView protein in PROSITE
PS50835. IG_LIKE. 3 hits.
PS00290. IG_MHC. 2 hits.

Sequencei

Sequence statusi: Complete.

P01877-1 [UniParc]FASTAAdd to basket

« Hide

        10         20         30         40         50
ASPTSPKVFP LSLDSTPQDG NVVVACLVQG FFPQEPLSVT WSESGQNVTA
60 70 80 90 100
RNFPPSQDAS GDLYTTSSQL TLPATQCPDG KSVTCHVKHY TNSSQDVTVP
110 120 130 140 150
CRVPPPPPCC HPRLSLHRPA LEDLLLGSEA NLTCTLTGLR DASGATFTWT
160 170 180 190 200
PSSGKSAVQG PPERDLCGCY SVSSVLPGCA QPWNHGETFT CTAAHPELKT
210 220 230 240 250
PLTANITKSG NTFRPEVHLL PPPSEELALN ELVTLTCLAR GFSPKDVLVR
260 270 280 290 300
WLQGSQELPR EKYLTWASRQ EPSQGTTTYA VTSILRVAAE DWKKGETFSC
310 320 330 340
MVGHEALPLA FTQKTIDRMA GKPTHINVSV VMAEADGTCY
Length:340
Mass (Da):36,591
Last modified:March 15, 2017 - v4
Checksum:i2DF338B77F520DCB
GO

Sequence cautioni

The sequence AAB59396 differs from that shown. Reason: Erroneous initiation. Translation N-terminally extended.Curated

Experimental Info

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Non-terminal residuei11
Sequence conflicti319M → L AA sequence (PubMed:416441).Curated1
Sequence conflicti319M → L in AAB59396 (PubMed:6421489).Curated1
Sequence conflicti319M → L AA sequence (PubMed:286295).Curated1

Polymorphismi

There are several alleles. The sequence shown is that of IMGT allele IGHA2*02.Curated

Natural variant

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Natural variantiVAR_00387993S → P in IMGT allele IGHA2*01. 2 Publications1
Natural variantiVAR_003880102R → P in IMGT allele IGHA2*01. 2 Publications1
Natural variantiVAR_003881279Y → F in IMGT allele IGHA2*01. 2 Publications1
Natural variantiVAR_003882296E → D in IMGT allele IGHA2*01. 2 Publications1
Natural variantiVAR_003883326I → V in IMGT allele IGHA2*01. 2 Publications1
Natural variantiVAR_003884335A → V in IMGT allele IGHA2*01. 2 Publications1

Sequence databases

Select the link destinations:
EMBLi
GenBanki
DDBJi
Links Updated
J00221 Genomic DNA. Translation: AAB59396.1. Different initiation.
AL928742 Genomic DNA. No translation available.
PIRiB22360.
UniGeneiHs.699841.

Genome annotation databases

EnsembliENST00000390539; ENSP00000374981; ENSG00000211890.

Keywords - Coding sequence diversityi

Polymorphism

Similar proteinsi

Entry informationi

Entry nameiIGHA2_HUMAN
AccessioniPrimary (citable) accession number: P01877
Secondary accession number(s): A0A075B6N7
Entry historyiIntegrated into UniProtKB/Swiss-Prot: July 21, 1986
Last sequence update: March 15, 2017
Last modified: August 30, 2017
This is version 151 of the entry and version 4 of the sequence. See complete history.
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.

Miscellaneousi

Caution

N-glycosylation was reported in milk on the non-canonical Asn-92 site (PubMed:18780401). However, according to Ref. 14, N-glycosylation from the same tissue was found to be absent at this site.1 Publication
For an example of a full length immunoglobulin alpha heavy chain see AC P0DOX2.Curated

Keywords - Technical termi

3D-structure, Complete proteome, Direct protein sequencing, Reference proteome

Documents

  1. Human chromosome 14
    Human chromosome 14: entries, gene names and cross-references to MIM
  2. Human entries with polymorphisms or disease mutations
    List of human entries with polymorphisms or disease mutations
  3. Human polymorphisms and disease mutations
    Index of human polymorphisms and disease mutations
  4. MIM cross-references
    Online Mendelian Inheritance in Man (MIM) cross-references in UniProtKB/Swiss-Prot
  5. PDB cross-references
    Index of Protein Data Bank (PDB) cross-references