Seroatlas · Human Serome Atlas

KLK2

Kallikrein-2

Also known as: KLK2_HUMAN

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

Protein identityUniProt · HPA

UniProt accession
P20151
Gene
KLK2
Ensembl
ENSG00000167751
Chromosome
19
Canonical length
261 aa
Protein class
Cancer-related genes, Enzymes, Metabolic proteins, Plasma proteins, Predicted intracellular proteins, Predicted secreted proteins
Secretome location
Secreted in male reproductive system

OverviewNCBI Gene

This gene encodes a member of the grandular kallikrein protein family. Kallikreins are a subgroup of serine proteases that are clustered on chromosome 19. Members of this family are involved in a diverse array of biological functions. The protein encoded by this gene is a highly active trypsin-like serine protease that selectively cleaves at arginine residues. This protein is primarily expressed in prostatic tissue and is responsible for cleaving pro-prostate-specific antigen into its enzymatically active form. This gene is highly expressed in prostate tumor cells and may be a prognostic maker for prostate cancer risk. Alternate splicing results in both coding and non-coding transcript variants. [provided by RefSeq, Jan 2012]

Canonical amino-acid sequenceUniProt

261 residues, UniProt reviewed canonical sequence.

>P20151|KLK2
     1  MWDLVLSIAL SVGCTGAVPL IQSRIVGGWE CEKHSQPWQV AVYSHGWAHC GGVLVHPQWV
    61  LTAAHCLKKN SQVWLGRHNL FEPEDTGQRV PVSHSFPHPL YNMSLLKHQS LRPDEDSSHD
   121  LMLLRLSEPA KITDVVKVLG LPTQEPALGT TCYASGWGSI EPEEFLRPRS LQCVSLHLLS
   181  NDMCARAYSE KVTEFMLCAG LWTGGKDTCG GDSGGPLVCN GVLQGITSWG PEPCALPEKP
   241  AVYTKVVHYR KWIKDTIAAN P

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against KLK2 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
Secreted
Secreted
Yes
Transmembrane segments
0
Mean surface accessibility (rSASA)
0.28
Highest tissue expression
531 nTPM

Expression across tissuesHPA

Tissue

  • prostate: 531 nTPM
  • bone marrow: 6.1 nTPM
  • testis: 2.9 nTPM
  • salivary gland: 1.7 nTPM
  • thyroid gland: 1.7 nTPM
  • retina: 1.5 nTPM

Single-cell type

  • prostatic glandular cells: 7,044 nCPM
  • basal prostatic cells: 76 nCPM
  • prostatic club cells: 45 nCPM
  • breast hormone-responsive cells: 39 nCPM
  • early primary spermatocytes: 37 nCPM
  • epididymal efferent duct absorptive cells: 29 nCPM

Immune cell

  • neutrophil: 1.6 nTPM
  • classical monocyte: 0.6 nTPM
  • naive B-cell: 0.6 nTPM
  • eosinophil: 0.5 nTPM
  • plasmacytoid DC: 0.5 nTPM
  • basophil: 0.4 nTPM

Brain region

  • white matter: 26 nTPM
  • cerebellum: 24 nTPM
  • midbrain: 21 nTPM
  • cerebral cortex: 21 nTPM
  • pons: 20 nTPM
  • amygdala: 20 nTPM

Genetic constraint and essentialitygnomAD · DepMap

Does the body need this protein intact? Low LOEUF or a strong DepMap dependency means loss or blockade of the protein is likely to be felt.

gnomAD LOEUF (loss-of-function intolerance)
1.36
gnomAD pLI
0
gnomAD missense Z
0.12
DepMap mean gene effect
0.02
DepMap dependency class
none

Cancer expressionTCGA

Across TCGA tumor cohorts, this protein is over-expressed in roughly 2% of surveyed tumor types (aggregate summary; per-cohort expression, alteration, and survival load in the interactive view).

OntologyGO

Biological processes

Molecular functions

Cellular components

Protein domainsUniProt · Pfam · InterPro

KeywordsUniProt

Antibody and autoantibody relevanceSeroatlas analysis

Seroatlas reads KLK2 as an antibody target. Whether an autoantibody or antibody against KLK2 could matter depends on whether native KLK2 is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

KLK2 is annotated as secreted, so native KLK2 circulates and is directly accessible to antibodies. Secreted and cell-surface proteins are the autoantibody targets most likely to act like drugs, blocking or depleting the native protein.

Annotation status

The present source text does not explicitly label KLK2 as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

Canonical record: https://seroatlas.com/gene/KLK2. 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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