Kallikreins are a subgroup of serine proteases having diverse physiological functions. Growing evidence suggests that many kallikreins are implicated in carcinogenesis and some have potential as novel cancer and other disease biomarkers. The gene is one of the fifteen kallikrein subfamily members located in a cluster on chromosome 19. It encodes a single-chain glycoprotein, a p... See more...

Aliases for KLK3 Gene

Aliases for KLK3 Gene

  • Kallikrein Related Peptidase 3 2 3 5
  • Prostate-Specific Antigen 3 4
  • Gamma-Seminoprotein 3 4
  • Kallikrein-3 3 4
  • Semenogelase 3 4
  • P-30 Antigen 3 4
  • Seminin 3 4
  • APS 3 4
  • PSA 3 4
  • Kallikrein 3, (Prostate Specific Antigen) 2
  • EC 4
  • EC 3.4.21 52
  • KLK2A1 3
  • HK3 3

External Ids for KLK3 Gene

Previous HGNC Symbols for KLK3 Gene

  • APS

Previous GeneCards Identifiers for KLK3 Gene

  • GC19P051987
  • GC19P051719
  • GC19P056034
  • GC19P056049
  • GC19P051358
  • GC19P047693

Summaries for KLK3 Gene

Entrez Gene Summary for KLK3 Gene

  • Kallikreins are a subgroup of serine proteases having diverse physiological functions. Growing evidence suggests that many kallikreins are implicated in carcinogenesis and some have potential as novel cancer and other disease biomarkers. The gene is one of the fifteen kallikrein subfamily members located in a cluster on chromosome 19. It encodes a single-chain glycoprotein, a protease which is synthesized in the epithelial cells of the prostate gland, and is present in seminal plasma. It is thought to function normally in the liquefaction of seminal coagulum, presumably by hydrolysis of the high molecular mass seminal vesicle protein. The serum level of this protein, called PSA in the clinical setting, is useful in the diagnosis and monitoring of prostatic carcinoma. Alternate splicing of this gene generates several transcript variants encoding different isoforms. [provided by RefSeq, Dec 2019]

GeneCards Summary for KLK3 Gene

KLK3 (Kallikrein Related Peptidase 3) is a Protein Coding gene. Diseases associated with KLK3 include Prostatitis and Urethral Stricture. Among its related pathways are Activated PKN1 stimulates transcription of AR (androgen receptor) regulated genes KLK2 and KLK3 and Adhesion. Gene Ontology (GO) annotations related to this gene include serine-type endopeptidase activity and serine-type peptidase activity. An important paralog of this gene is KLK2.

UniProtKB/Swiss-Prot Summary for KLK3 Gene

  • Hydrolyzes semenogelin-1 thus leading to the liquefaction of the seminal coagulum.

Gene Wiki entry for KLK3 Gene

Additional gene information for KLK3 Gene

No data available for CIViC Summary , Tocris Summary , PharmGKB "VIP" Summary , Rfam classification and piRNA Summary for KLK3 Gene

Genomics for KLK3 Gene

GeneHancer (GH) Regulatory Elements for KLK3 Gene

Promoters and enhancers for KLK3 Gene
GeneHancer (GH) Identifier GH Type GH
GH Sources Gene Association Score Total Score TSS distance (kb) Number of Genes Away Size (kb) Transcription Factor
Binding Sites
Gene Targets
GH19J050854 Promoter/Enhancer 0.5 EPDnew dbSUPER 500.7 0.0 -19 0.1 KLK3 RF00017-3058 KLK1 LINC01869 C19orf48 SNORD88C SNORD88A SNORD88B
GH19J050855 Enhancer 0.2 dbSUPER 506 +1.4 1379 1.4 KLK3 KLK1 LINC01869 C19orf48 SNORD88C KLK2 SNORD88A SNORD88B lnc-KLK3-2
GH19J050835 Promoter/Enhancer 1.7 FANTOM5 ENCODE CraniofacialAtlas dbSUPER 10 -18.8 -18785 1.2 NRF1 USF1 PHF8 ZNF10 POLR2A ZBTB10 ZNF423 ZBTB26 REST CTBP1 KLK15 ZNF175 ENSG00000268047 NUP62 PTOV1-AS2 C19orf48 SNORD88C LINC01869 KLK2 SNORD88A
GH19J050414 Promoter/Enhancer 1.8 EPDnew Ensembl ENCODE dbSUPER 5.8 -437.2 -437203 7.1 CTCF ZSCAN5C SIN3A NRF1 TCF12 MYC USF1 SP1 POLR2A ZBTB10 ENSG00000142539 SPIB POLD1 NAPSB KLK3
GH19J050843 Enhancer 0.6 dbSUPER 6 -10.8 -10824 2.2 RBAK ZIC2 ZEB1 ZNF341 TCF7L2 TRIM28 MEF2B ZNF280A EBF1 SCRT1 KLK1 LINC01869 SNORD88A SNORD88B SNORD88C C19orf48 CLEC11A KLK14 KLK3 RF00017-3058
- Elite GeneHancer and/or Elite GeneHancer-gene association Download GeneHancer data from 2017 publication | Request up-to-date GeneHancer data (full dataset)

GeneHancers around KLK3 on UCSC Golden Path with GeneCards custom track

Cistromic (ChIP-Seq) regulation report from SPP (The Signaling Pathways Project) for KLK3

Top Transcription factor binding sites by QIAGEN in the KLK3 gene promoter:
  • STAT3

Genomic Locations for KLK3 Gene

Genomic Locations for KLK3 Gene
22,788 bases
Plus strand
5,850 bases
Plus strand

Genomic View for KLK3 Gene

Genes around KLK3 on UCSC Golden Path with GeneCards custom track

Cytogenetic band:
KLK3 Gene in genomic location: bands according to Ensembl, locations according to GeneLoc (and/or Entrez Gene and/or Ensembl if different)
Genomic Location for KLK3 Gene
GeneLoc Logo Genomic Neighborhood Exon StructureGene Density

RefSeq DNA sequence for KLK3 Gene

Proteins for KLK3 Gene

  • Protein details for KLK3 Gene (UniProtKB/Swiss-Prot)

    Protein Symbol:
    Recommended name:
    Prostate-specific antigen
    Protein Accession:
    Secondary Accessions:
    • C9JXH3
    • G3V0H4
    • G3XAE3
    • Q15096
    • Q16272
    • Q86TG8
    • Q8IXI4

    Protein attributes for KLK3 Gene

    261 amino acids
    Molecular mass:
    28741 Da
    Quaternary structure:
    • Forms a heterodimer with SERPINA5.
    • Sequence=AAD14185.1; Type=Erroneous initiation; Note=Extended N-terminus.; Evidence={ECO:0000305}; Sequence=CAA32124.1; Type=Miscellaneous discrepancy; Evidence={ECO:0000305};

    Three dimensional structures from OCA and Proteopedia for KLK3 Gene

    Alternative splice isoforms for KLK3 Gene


neXtProt entry for KLK3 Gene

Selected DME Specific Peptides for KLK3 Gene


Post-translational modifications for KLK3 Gene

  • Glycosylation at Asn69
  • Modification sites at PhosphoSitePlus
  • Glycosylation from GlyConnect
    • KLK3_HUMAN (790)

Antibody Products

Domains & Families for KLK3 Gene

Gene Families for KLK3 Gene

Human Protein Atlas (HPA):
  • Cancer-related genes
  • Enzymes
  • Plasma proteins
  • Predicted secreted proteins

Protein Domains for KLK3 Gene

  • Serine protease, trypsin family
  • Chymotrypsin serine protease family (S1) signature

Suggested Antigen Peptide Sequences for KLK3 Gene

GenScript: Design optimal peptide antigens:
  • Semenogelase (KLK3_HUMAN)
  • APS protein (Q15096_HUMAN)
  • APS protein (Q15098_HUMAN)
  • cDNA, FLJ93384, Homo sapiens kallikrein 3, (prostate specific antigen) (KLK3),transcript variant 1, mRNA (Q546G3_HUMAN)
  • APS protein (Q6LDS3_HUMAN)

Graphical View of Domain Structure for InterPro Entry



  • Belongs to the peptidase S1 family. Kallikrein subfamily.
  • Belongs to the peptidase S1 family. Kallikrein subfamily.
genes like me logo Genes that share domains with KLK3: view

Function for KLK3 Gene

Molecular function for KLK3 Gene

UniProtKB/Swiss-Prot Function:
Hydrolyzes semenogelin-1 thus leading to the liquefaction of the seminal coagulum.
UniProtKB/Swiss-Prot CatalyticActivity:
Reaction=Preferential cleavage: -Tyr- -Xaa-.; EC=;.
UniProtKB/Swiss-Prot EnzymeRegulation:
Inhibited by SERPINA5. Activity is strongly inhibited by Zn2+, 100 times more abundant in semen than in serum. This inhibition is relieved by exposure to semenogelins, which are avid zinc binders.
GENATLAS Biochemistry:
kallikrein 3,prostate specific antigen,serine protease,overexpressed in prostate and breast carcinomas

Enzyme Numbers (IUBMB) for KLK3 Gene

Phenotypes From GWAS Catalog for KLK3 Gene

Gene Ontology (GO) - Molecular Function for KLK3 Gene

GO ID Qualified GO term Evidence PubMed IDs
GO:0004175 endopeptidase activity IDA 18714013
GO:0004252 serine-type endopeptidase activity IMP,IEA 15563730
GO:0005515 protein binding IPI 1725227
GO:0008233 peptidase activity IEA --
GO:0008236 serine-type peptidase activity IEA,TAS 2470553
genes like me logo Genes that share ontologies with KLK3: view
genes like me logo Genes that share phenotypes with KLK3: view

miRNA for KLK3 Gene

miRTarBase miRNAs that target KLK3

Clone Products

No data available for Human Phenotype Ontology , Animal Models , Transcription Factor Targets and HOMER Transcription for KLK3 Gene

Localization for KLK3 Gene

Subcellular locations from UniProtKB/Swiss-Prot for KLK3 Gene


Subcellular locations from

Extracellular space Cytosol Plasma membrane Cytoskeleton Lysosome Endosome Peroxisome ER Golgi Apparatus Nucleus Mitochondrion 0 1 2 3 4 5 Confidence
COMPARTMENTS Subcellular localization image for KLK3 gene
Compartment Confidence
extracellular 5
plasma membrane 3
nucleus 3
cytosol 3
cytoskeleton 2
mitochondrion 2
endoplasmic reticulum 2
endosome 2
lysosome 2
peroxisome 1
golgi apparatus 1

Gene Ontology (GO) - Cellular Components for KLK3 Gene

GO ID Qualified GO term Evidence PubMed IDs
GO:0005576 extracellular region TAS --
GO:0005615 extracellular space IDA 8665956
GO:0005634 nucleus HDA 21630459
GO:0030141 secretory granule IBA 21873635
GO:0032991 protein-containing complex IDA 8665956
genes like me logo Genes that share ontologies with KLK3: view

No data available for Subcellular locations from the Human Protein Atlas (HPA) for KLK3 Gene

Pathways & Interactions for KLK3 Gene

genes like me logo Genes that share pathways with KLK3: view

Pathways by source for KLK3 Gene

2 GeneGo (Thomson Reuters) pathways for KLK3 Gene
  • Cell adhesion_ECM remodeling
  • Transcription Androgen Receptor nuclear signaling
4 Qiagen pathways for KLK3 Gene
  • Blood Coagulation Cascade
  • Insulin Receptor Pathway
  • Intrinsic Prothrombin Activation Pathway
  • MSP-RON Signaling
1 Cell Signaling Technology pathway for KLK3 Gene

SIGNOR curated interactions for KLK3 Gene

Is activated by:
Is inactivated by:

Gene Ontology (GO) - Biological Process for KLK3 Gene

GO ID Qualified GO term Evidence PubMed IDs
GO:0002778 antibacterial peptide production IDA 18714013
GO:0003073 regulation of systemic arterial blood pressure IBA 21873635
GO:0006508 proteolysis IEA,IMP 15563730
GO:0016525 negative regulation of angiogenesis NAS 10675891
GO:0031638 zymogen activation IBA 21873635
genes like me logo Genes that share ontologies with KLK3: view

Drugs & Compounds for KLK3 Gene

(88) Drugs for KLK3 Gene - From: DrugBank, DGIdb, and Novoseek

Name Status Disease Links Group Role Mechanism of Action Clinical Trials
Cyproterone Acetate Approved, Investigational Pharma Target Androgen receptor antagonist 46
Mifepristone Approved, Investigational Pharma Agonist, Antagonist, Mixed, Target Progesterone receptor antagonist, Progesterone and glucocorticoid receptor antagonist 179
MVA-BN Pharma 0
PRX302 Pharma 0

(39) Additional Compounds for KLK3 Gene - From: Novoseek

Name Synonyms Role CAS Number PubChem IDs PubMed IDs
genes like me logo Genes that share compounds with KLK3: view

Transcripts for KLK3 Gene

mRNA/cDNA for KLK3 Gene

29 NCBI additional mRNA sequence :
16 Ensembl transcripts including schematic representations, and UCSC links to gene/alias where relevant :

Clone Products

Alternative Splicing Database (ASD) splice patterns (SP) for KLK3 Gene

ExUns: 1a · 1b · 1c · 1d · 1e · 1f ^ 2a · 2b · 2c · 2d ^ 3a · 3b · 3c ^ 4a · 4b · 4c · 4d ^ 5 ^ 6a · 6b · 6c · 6d · 6e · 6f
SP1: - - - - - -
SP2: - - - - -
SP3: - - - - - -
SP4: - - - - - - -
SP5: - - - - -
SP6: - - - - -
SP7: - - - -
SP8: - - -
SP9: - -
SP10: - - -
SP11: - -
SP12: - - - -
SP13: - - - - -

Relevant External Links for KLK3 Gene

GeneLoc Exon Structure for

Expression for KLK3 Gene

mRNA expression in normal human tissues from GTEx, Illumina, BioGPS, and SAGE for KLK3 Gene

mRNA expression in embryonic tissues and stem cells from LifeMap Discovery

mRNA differential expression in normal tissues according to GTEx for KLK3 Gene

This gene is overexpressed in Prostate (x52.7).

Protein differential expression in normal tissues from HIPED for KLK3 Gene

This gene is overexpressed in Cervix (32.5) and Prostate (27.7).

Integrated Proteomics: protein expression in normal tissues and cell lines from ProteomicsDB, MaxQB, and MOPED for KLK3 Gene

Protein tissue co-expression partners for KLK3 Gene

Transcriptomic regulation report from SPP (The Signaling Pathways Project) for KLK3

SOURCE GeneReport for Unigene cluster for KLK3 Gene:


Evidence on tissue expression from TISSUES for KLK3 Gene

  • Blood(4.6)
  • Nervous system(4.6)
  • Intestine(3.5)
  • Lymph node(3)
  • Urine(2.8)
  • Bone(2.4)
genes like me logo Genes that share expression patterns with KLK3: view

No data available for mRNA Expression by UniProt/SwissProt and Phenotype-based relationships between genes and organs from Gene ORGANizer for KLK3 Gene

Orthologs for KLK3 Gene

This gene was present in the common ancestor of chordates.

Orthologs for KLK3 Gene

Organism Taxonomy Gene Similarity Type Details
(Pan troglodytes)
Mammalia KLK3 31
  • 92 (a)
(Mus musculus)
Mammalia Klk1b22 30
  • 65.49 (n)
Klk1b16 31
  • 51 (a)
Klk1b9 17
(Canis familiaris)
Mammalia KLK2 31
  • 56 (a)
(Bos Taurus)
Mammalia -- 31
  • 27 (a)
(Anolis carolinensis)
Reptilia -- 31
  • 35 (a)
Species where no ortholog for KLK3 was found in the sources mined by GeneCards:
  • A. gosspyii yeast (Ashbya gossypii)
  • Actinobacteria (Mycobacterium tuberculosis)
  • African clawed frog (Xenopus laevis)
  • African malaria mosquito (Anopheles gambiae)
  • Alicante grape (Vitis vinifera)
  • alpha proteobacteria (Wolbachia pipientis)
  • amoeba (Dictyostelium discoideum)
  • Archea (Pyrococcus horikoshii)
  • baker's yeast (Saccharomyces cerevisiae)
  • barley (Hordeum vulgare)
  • beta proteobacteria (Neisseria meningitidis)
  • bread mold (Neurospora crassa)
  • chicken (Gallus gallus)
  • Chromalveolata (Phytophthora infestans)
  • common water flea (Daphnia pulex)
  • corn (Zea mays)
  • E. coli (Escherichia coli)
  • filamentous fungi (Aspergillus nidulans)
  • Firmicute bacteria (Streptococcus pneumoniae)
  • fission yeast (Schizosaccharomyces pombe)
  • fruit fly (Drosophila melanogaster)
  • green algae (Chlamydomonas reinhardtii)
  • honey bee (Apis mellifera)
  • K. lactis yeast (Kluyveromyces lactis)
  • loblloly pine (Pinus taeda)
  • malaria parasite (Plasmodium falciparum)
  • medicago trunc (Medicago Truncatula)
  • moss (Physcomitrella patens)
  • oppossum (Monodelphis domestica)
  • orangutan (Pongo pygmaeus)
  • pig (Sus scrofa)
  • platypus (Ornithorhynchus anatinus)
  • rainbow trout (Oncorhynchus mykiss)
  • rat (Rattus norvegicus)
  • rice (Oryza sativa)
  • rice blast fungus (Magnaporthe grisea)
  • schistosome parasite (Schistosoma mansoni)
  • sea anemone (Nematostella vectensis)
  • sea squirt (Ciona intestinalis)
  • sea squirt (Ciona savignyi)
  • sea urchin (Strongylocentrotus purpuratus)
  • sorghum (Sorghum bicolor)
  • soybean (Glycine max)
  • stem rust fungus (Puccinia graminis)
  • sugarcane (Saccharum officinarum)
  • thale cress (Arabidopsis thaliana)
  • tomato (Lycopersicon esculentum)
  • toxoplasmosis (Toxoplasma gondii)
  • Trichoplax (Trichoplax adhaerens)
  • tropical clawed frog (Silurana tropicalis)
  • wheat (Triticum aestivum)
  • worm (Caenorhabditis elegans)
  • zebrafish (Danio rerio)

Evolution for KLK3 Gene

Gene Tree for KLK3 (if available)
Gene Tree for KLK3 (if available)
Evolutionary constrained regions (ECRs) for KLK3: view image

Paralogs for KLK3 Gene

Paralogs for KLK3 Gene

(59) SIMAP similar genes for KLK3 Gene using alignment to 10 proteins:

  • M0QX57_HUMAN
  • M0R1F0_HUMAN
  • M0R1Z7_HUMAN
  • M0R294_HUMAN
  • Q546G3_HUMAN
  • Q96A30_HUMAN

Pseudogenes.org Pseudogenes for KLK3 Gene

genes like me logo Genes that share paralogs with KLK3: view

Variants for KLK3 Gene

Sequence variations, with clinical significance, from ClinVar and Humsavar, with links to dbSNP for KLK3 Gene

SNP ID Clinical significance and condition Chr 19 pos Variation AA Info Type
722680 Likely Benign: not provided 50,858,496(+) T/C SYNONYMOUS_VARIANT
778603 Benign: not provided 50,856,309(+) A/T MISSENSE_VARIANT
784838 Benign: not provided 50,856,287(+) G/A MISSENSE_VARIANT
790764 Benign: not provided 50,860,022(+) G/A SYNONYMOUS_VARIANT,THREE_PRIME_UTR_VARIANT
rs17632542 - p.Ile179Thr

Additional dbSNP identifiers (rs#s) for KLK3 Gene

Structural Variations from Database of Genomic Variants (DGV) for KLK3 Gene

Variant ID Type Subtype PubMed ID
esv2763208 CNV gain 21179565
nsv1140251 OTHER inversion 24896259
nsv2531 CNV deletion 18451855
nsv524465 CNV loss 19592680

Variation tolerance for KLK3 Gene

Residual Variation Intolerance Score: 87.4% of all genes are more intolerant (likely to be disease-causing)
Gene Damage Index Score: 2.84; 47.96% of all genes are more intolerant (likely to be disease-causing)

Additional Variant Information for KLK3 Gene

Human Gene Mutation Database (HGMD)
SNPedia medical, phenotypic, and genealogical associations of SNPs for

SNP Genotyping and Copy Number Assay Products

No data available for Polymorphic Variants from UniProtKB/Swiss-Prot for KLK3 Gene

Disorders for KLK3 Gene

MalaCards: The human disease database

(94) MalaCards diseases for KLK3 Gene - From: DISEASES, Novoseek, and GeneCards

Disorder Aliases PubMed IDs
urethral stricture
prostatic adenoma
  • adenoma - prostate
prostatic hypertrophy
  • prostatic hyperplasia
nodular prostate
- elite association - COSMIC cancer census association via MalaCards
Search KLK3 in MalaCards View complete list of genes associated with diseases

Additional Disease Information for KLK3

Genetic Association Database
Human Genome Epidemiology Navigator
ATLAS of Genetics and Cytogenetics in Oncology and Haematology
genes like me logo Genes that share disorders with KLK3: view

No data available for UniProtKB/Swiss-Prot and Genatlas for KLK3 Gene

Publications for KLK3 Gene

  1. Shorter CAG repeats in androgen receptor and non-GG genotypes in prostate-specific antigen loci are associated with decreased risk of benign prostatic hyperplasia and prostate cancer. (PMID: 18495332) Das K … Lau W (Cancer letters 2008) 3 23 41 54
  2. Crystal structure of a ternary complex between human prostate-specific antigen, its substrate acyl intermediate and an activating antibody. (PMID: 18187150) Ménez R … Stura EA (Journal of molecular biology 2008) 3 4 23 54
  3. Evaluation of genetic variations in the androgen and estrogen metabolic pathways as risk factors for sporadic and familial prostate cancer. (PMID: 17507624) Cunningham JM … Thibodeau SN (Cancer epidemiology, biomarkers & prevention : a publication of the American Association for Cancer Research, cosponsored by the American Society of Preventive Oncology 2007) 3 23 41 54
  4. A G/A polymorphism in the androgen response element 1 of prostate-specific antigen gene correlates with the response to androgen deprivation therapy in Japanese population. (PMID: 17094454) Shibahara T … Sugimura Y (Anticancer research 2006) 3 23 41 54
  5. Polymorphism in ARE-I region of prostate-specific antigen gene associated with low serum testosterone level and high-grade prostate cancer. (PMID: 15893813) Schatzl G … Gsur A (Urology 2005) 3 23 41 54

Products for KLK3 Gene

Sources for KLK3 Gene