Seroatlas · Human Serome Atlas

KLK4

Kallikrein-4

Also known as: EMSP, EMSP1, KLK-L1, KLK4_HUMAN, PRSS17, PSTS

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

Protein identityUniProt · HPA

UniProt accession: Q9Y5K2
Gene: KLK4
Ensembl: ENSG00000167749
Chromosome: 19
Canonical length: 254 aa
Protein class: Cancer-related genes, Disease related genes, Enzymes, Human disease related genes, Potential drug targets, Predicted intracellular proteins, Predicted secreted proteins
Secretome location: Secreted in male reproductive system

OverviewNCBI 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. This gene is one of the fifteen kallikrein subfamily members located in a cluster on chromosome 19. In some tissues its expression is hormonally regulated. The expression pattern of a similar mouse protein in murine developing teeth supports a role for the protein in the degradation of enamel proteins. Several transcript variants encoding different proteins have been found for this gene. [provided by RefSeq, Dec 2014]

Canonical amino-acid sequenceUniProt

254 residues, UniProt reviewed canonical sequence.

>Q9Y5K2|KLK4
     1  MATAGNPWGW FLGYLILGVA GSLVSGSCSQ IINGEDCSPH SQPWQAALVM ENELFCSGVL
    61  VHPQWVLSAA HCFQNSYTIG LGLHSLEADQ EPGSQMVEAS LSVRHPEYNR PLLANDLMLI
   121  KLDESVSESD TIRSISIASQ CPTAGNSCLV SGWGLLANGR MPTVLQCVNV SVVSEEVCSK
   181  LYDPLYHPSM FCAGGGHDQK DSCNGDSGGP LICNGYLQGL VSFGKAPCGQ VGVPGVYTNL
   241  CKFTEWIEKT VQAS

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against KLK4 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): 0.29
Highest tissue expression: 260 nTPM

Expression across tissuesHPA

Tissue

prostate: 260 nTPM
skin: 7.9 nTPM
cervix: 7.3 nTPM
duodenum: 6.4 nTPM
small intestine: 4.5 nTPM
salivary gland: 4.3 nTPM

Single-cell type

prostatic glandular cells: 518 nCPM
epididymal efferent duct absorptive cells: 214 nCPM
epididymal efferent duct ciliated cells: 27 nCPM
prostatic club cells: 27 nCPM
goblet cells: 8.5 nCPM
basal prostatic cells: 6.3 nCPM

Immune cell

basophil: 0 nTPM
classical monocyte: 0 nTPM
eosinophil: 0 nTPM
gdT-cell: 0 nTPM
intermediate monocyte: 0 nTPM
MAIT T-cell: 0 nTPM

Brain region

cerebellum: 4.8 nTPM
medulla oblongata: 4.7 nTPM
pons: 4.7 nTPM
cerebral cortex: 3.6 nTPM
hypothalamus: 3.1 nTPM
midbrain: 3 nTPM

DiseaseUniProt · ClinVar · IEDB · PubMed

Four sources answering four different questions about KLK4.

Disease | AllUniProt

Conditions KLK4 is implicated in, by any mechanism.

Amelogenesis imperfecta, hypomaturation type, 2A1 (AI2A1) MIM:204700

Disease | GeneticClinVar

7 pathogenic / likely-pathogenic of 62 ClinVar records.

Conditions with pathogenic or likely-pathogenic variants.

Amelogenesis imperfecta type 2A1
Amelogenesis imperfecta

Disease | ImmuneIEDB

Conditions an epitope on KLK4 was assayed in.

prostate cancer T cell

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): 1.46
gnomAD pLI: 0
gnomAD missense Z: 0.03
DepMap mean gene effect: 0.01
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 KLK4 as an antibody target. Whether an autoantibody or antibody against KLK4 could matter depends on whether native KLK4 is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

KLK4 is annotated as secreted, so native KLK4 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 KLK4 as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

Loading the interactive Seroatlas protein explorer...