Seroatlas · Human Serome Atlas

IGKV3-20

Immunoglobulin kappa variable 3-20

Also known as: KV320_HUMAN

Cross-references: UniProt · Ensembl · Human Protein Atlas · GeneCards · NCBI Gene

Protein identityUniProt · HPA

UniProt accession
P01619
Gene
IGKV3-20
Ensembl
ENSG00000239951
Chromosome
2
Canonical length
116 aa
Protein class
Immunoglobulin genes, Predicted secreted proteins
Subcellular location
Plasma membrane,Cytosol
Secretome location
Immunoglobulin genes

OverviewNCBI Gene

Predicted to enable antigen binding activity. Involved in glomerular filtration. Located in extracellular space. Part of monomeric IgA immunoglobulin complex; pentameric IgM immunoglobulin complex; and secretory IgA immunoglobulin complex. [provided by Alliance of Genome Resources, Jul 2025]

Canonical amino-acid sequenceUniProt

116 residues, UniProt reviewed canonical sequence.

>P01619|IGKV3-20
     1  METPAQLLFL LLLWLPDTTG EIVLTQSPGT LSLSPGERAT LSCRASQSVS SSYLAWYQQK
    61  PGQAPRLLIY GASSRATGIP DRFSGSGSGT DFTLTISRLE PEDFAVYYCQ QYGSSP

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against IGKV3-20 can act on the native protein depends on physical access: surface and secreted proteins are reachable by circulating antibodies, intracellular proteins usually are not.

Antibody reachability
Cell surface
Secreted
No
Transmembrane segments
0
Highest tissue expression
4,893 nTPM

Expression across tissuesHPA

Tissue

  • tonsil: 4,893 nTPM
  • colon: 2,877 nTPM
  • lymph node: 2,640 nTPM
  • rectum: 2,554 nTPM
  • spleen: 2,554 nTPM
  • appendix: 1,687 nTPM

Single-cell type

  • plasma cells: 58 nCPM
  • gastric chief cells: 11 nCPM
  • foveolar cells: 7.9 nCPM
  • mucous neck cells: 5.1 nCPM
  • parietal cells: 3.5 nCPM
  • neuroendocrine cells: 2.3 nCPM

Immune cell

  • memory B-cell: 1,610 nTPM
  • naive B-cell: 1,230 nTPM
  • total PBMC: 197 nTPM
  • neutrophil: 4.3 nTPM
  • basophil: 4 nTPM
  • myeloid DC: 3.5 nTPM

Brain region

  • spinal cord: 18 nTPM
  • midbrain: 14 nTPM
  • cerebral cortex: 5.6 nTPM
  • choroid plexus: 4.1 nTPM
  • medulla oblongata: 3 nTPM
  • hypothalamus: 2.2 nTPM

DiseaseUniProt · ClinVar · IEDB · PubMed

Four sources answering four different questions about IGKV3-20.

Disease | ImmuneIEDB

Conditions an epitope on IGKV3-20 was assayed in.

  • plasma cell leukemia T cell

OntologyGO

Biological processes

Molecular functions

Cellular components

Protein domainsUniProt · Pfam · InterPro

KeywordsUniProt

Antibody and autoantibody relevanceSeroatlas analysis

Seroatlas reads IGKV3-20 as an antibody target. Whether an autoantibody or antibody against IGKV3-20 could matter depends on whether native IGKV3-20 is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

IGKV3-20 is annotated at the cell surface, where native IGKV3-20 is exposed to circulating antibodies and is a prime autoantibody target that could block, deplete, or overstimulate it.

Annotation status

The present source text does not explicitly label IGKV3-20 as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

Canonical record: https://seroatlas.com/gene/IGKV3-20. Study-independent annotations aggregated from UniProt, Human Protein Atlas, PubMed, IEDB, Pfam, InterPro, Gene Ontology, AlphaFold, gnomAD, DepMap, ClinVar, TCGA. Catalog release seroatlas-reviewed-human-uniprot-20260313.

Seroatlas is the reference for exploring autoantibody and antibody serology at the human-protein level: the autoreactome and human serome, multiplex serology (HuProt, HuScan, VirScan, PhIP-Seq).

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