Seroatlas · Human Serome Atlas

KLKB1

Plasma kallikrein

Also known as: KLK3, KLKB1_HUMAN

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

Protein identityUniProt · HPA

UniProt accession: P03952
Gene: KLKB1
Ensembl: ENSG00000164344
Chromosome: 4
Canonical length: 638 aa
Protein class: Disease related genes, Enzymes, FDA approved drug targets, Human disease related genes, Plasma proteins, Predicted intracellular proteins, Predicted secreted proteins
Secretome location: Secreted to blood

OverviewNCBI Gene

This gene encodes a glycoprotein that participates in the surface-dependent activation of blood coagulation, fibrinolysis, kinin generation and inflammation. The encoded preproprotein present in plasma as a non-covalent complex with high molecular weight kininogen undergoes proteolytic processing mediated by activated coagulation factor XII to generate a disulfide-linked, heterodimeric serine protease comprised of heavy and light chains. Certain mutations in this gene cause prekallikrein deficiency. Alternative splicing results in multiple transcript variants encoding different isoforms. [provided by RefSeq, Jan 2016]

Canonical amino-acid sequenceUniProt

638 residues, UniProt reviewed canonical sequence.

>P03952|KLKB1
     1  MILFKQATYF ISLFATVSCG CLTQLYENAF FRGGDVASMY TPNAQYCQMR CTFHPRCLLF
    61  SFLPASSIND MEKRFGCFLK DSVTGTLPKV HRTGAVSGHS LKQCGHQISA CHRDIYKGVD
   121  MRGVNFNVSK VSSVEECQKR CTSNIRCQFF SYATQTFHKA EYRNNCLLKY SPGGTPTAIK
   181  VLSNVESGFS LKPCALSEIG CHMNIFQHLA FSDVDVARVL TPDAFVCRTI CTYHPNCLFF
   241  TFYTNVWKIE SQRNVCLLKT SESGTPSSST PQENTISGYS LLTCKRTLPE PCHSKIYPGV
   301  DFGGEELNVT FVKGVNVCQE TCTKMIRCQF FTYSLLPEDC KEEKCKCFLR LSMDGSPTRI
   361  AYGTQGSSGY SLRLCNTGDN SVCTTKTSTR IVGGTNSSWG EWPWQVSLQV KLTAQRHLCG
   421  GSLIGHQWVL TAAHCFDGLP LQDVWRIYSG ILNLSDITKD TPFSQIKEII IHQNYKVSEG
   481  NHDIALIKLQ APLNYTEFQK PICLPSKGDT STIYTNCWVT GWGFSKEKGE IQNILQKVNI
   541  PLVTNEECQK RYQDYKITQR MVCAGYKEGG KDACKGDSGG PLVCKHNGMW RLVGITSWGE
   601  GCARREQPGV YTKVAEYMDW ILEKTQSSDG KAQMQSPA

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against KLKB1 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): 0.24
Highest tissue expression: 307 nTPM

Expression across tissuesHPA

Tissue

liver: 307 nTPM
retina: 11 nTPM
choroid plexus: 8.2 nTPM
kidney: 6.9 nTPM
pancreas: 4.8 nTPM
basal ganglia: 4.6 nTPM

Single-cell type

choroid plexus epithelial cells: 115 nCPM
astrocytes: 99 nCPM
proximal tubule cells: 76 nCPM
ependymal cells: 70 nCPM
loop of henle epithelial cells: 38 nCPM
bergmann glia: 36 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

choroid plexus: 11 nTPM
medulla oblongata: 6.5 nTPM
cerebral cortex: 5.8 nTPM
pons: 5.3 nTPM
white matter: 5.3 nTPM
basal ganglia: 5.1 nTPM

DiseaseUniProt · ClinVar · IEDB · PubMed

Four sources answering four different questions about KLKB1.

Disease | AllUniProt

Conditions KLKB1 is implicated in, by any mechanism.

Prekallikrein deficiency (PKKD) MIM:612423

Disease | GeneticClinVar

13 pathogenic / likely-pathogenic of 160 ClinVar records.

Conditions with pathogenic or likely-pathogenic variants.

Inherited prekallikrein deficiency
Prekallikrein deficiency
KLKB1-related disorder

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
gnomAD pLI: 0
gnomAD missense Z: 0.7
DepMap mean gene effect: 0.09
DepMap dependency class: none

Cancer expressionTCGA

Across TCGA tumor cohorts, this protein is over-expressed in roughly 3% 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 KLKB1 as an antibody target. Whether an autoantibody or antibody against KLKB1 could matter depends on whether native KLKB1 is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

KLKB1 is annotated as secreted, so native KLKB1 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 KLKB1 as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

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