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Aliases for CTSK Gene

Aliases for CTSK Gene

  • Cathepsin K 2 3
  • Cathepsin O2 3 4
  • EC 4 63
  • Cathepsin X 3 4
  • Cathepsin O 3 4
  • CTSO2 3 4
  • CTSO 3 4
  • Cathepsin K (Pycnodysostosis) 2
  • Cathepsin O1 3
  • EC 3.4.22 63
  • CTSO1 3
  • CTS02 3
  • PKND 3
  • PYCD 3

External Ids for CTSK Gene

Previous HGNC Symbols for CTSK Gene

  • CTSO2
  • CTSO
  • PYCD

Previous GeneCards Identifiers for CTSK Gene

  • GC01M148610
  • GC01M146515
  • GC01M147543
  • GC01M147985
  • GC01M147581
  • GC01M149035
  • GC01M122146

Summaries for CTSK Gene

Entrez Gene Summary for CTSK Gene

  • The protein encoded by this gene is a lysosomal cysteine proteinase involved in bone remodeling and resorption. This protein, which is a member of the peptidase C1 protein family, is predominantly expressed in osteoclasts. However, the encoded protein is also expressed in a significant fraction of human breast cancers, where it could contribute to tumor invasiveness. Mutations in this gene are the cause of pycnodysostosis, an autosomal recessive disease characterized by osteosclerosis and short stature. [provided by RefSeq, Apr 2013]

GeneCards Summary for CTSK Gene

CTSK (Cathepsin K) is a Protein Coding gene. Diseases associated with CTSK include pycnodysostosis and kindler syndrome. Among its related pathways are Immune System and Degradation of the extracellular matrix. GO annotations related to this gene include cysteine-type endopeptidase activity and collagen binding. An important paralog of this gene is CTSW.

UniProtKB/Swiss-Prot for CTSK Gene

  • Closely involved in osteoclastic bone resorption and may participate partially in the disorder of bone remodeling. Displays potent endoprotease activity against fibrinogen at acid pH. May play an important role in extracellular matrix degradation

Tocris Summary for CTSK Gene

  • Cathepsins are a group of lysosomal proteases that have a key role in cellular protein turnover. The term cathepsin includes serine proteases (cathepsins A and G), aspartic proteases (cathepsin D and E) as well as the cysteine proteases (cathepsins B, C, F, H, K, L, O, S, W and Z).

Gene Wiki entry for CTSK Gene

No data available for PharmGKB "VIP" Summary , fRNAdb sequence ontologies and piRNA Summary for CTSK Gene

Genomics for CTSK Gene

Regulatory Elements for CTSK Gene

Genomic Location for CTSK Gene

150,796,208 bp from pter
150,808,441 bp from pter
12,234 bases
Minus strand

Genomic View for CTSK Gene

UCSC Golden Path with GeneCards custom track
Cytogenetic band:
Genomic Location for CTSK Gene
GeneLoc Logo Genomic Neighborhood Exon StructureGene Density

RefSeq DNA sequence for CTSK Gene

Proteins for CTSK Gene

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

    Protein Symbol:
    Recommended name:
    Cathepsin K
    Protein Accession:
    Secondary Accessions:
    • Q6FHS6

    Protein attributes for CTSK Gene

    329 amino acids
    Molecular mass:
    36966 Da
    Quaternary structure:
    No Data Available

    Three dimensional structures from OCA and Proteopedia for CTSK Gene

neXtProt entry for CTSK Gene

Proteomics data for CTSK Gene at MOPED

Post-translational modifications for CTSK Gene

  • Glycosylation at Asn 103
  • Modification sites at PhosphoSitePlus

Other Protein References for CTSK Gene

ENSEMBL proteins:
REFSEQ proteins:

Antibody Products

Domains & Families for CTSK Gene

Gene Families for CTSK Gene

Suggested Antigen Peptide Sequences for CTSK Gene

Graphical View of Domain Structure for InterPro Entry



  • Belongs to the peptidase C1 family.
  • Belongs to the peptidase C1 family.
genes like me logo Genes that share domains with CTSK: view

Function for CTSK Gene

Molecular function for CTSK Gene

GENATLAS Biochemistry:
cathepsin K,lysosomal P cysteine proteinase,expressed in osteoclats and multinucleated and chondroclasts at the osteochondral junction and the surfaces bone spicules,likely major protein in bone matrix resorption
UniProtKB/Swiss-Prot CatalyticActivity:
Broad proteolytic activity. With small-molecule substrates and inhibitors, the major determinant of specificity is P2, which is preferably Leu, Met > Phe, and not Arg
UniProtKB/Swiss-Prot Function:
Closely involved in osteoclastic bone resorption and may participate partially in the disorder of bone remodeling. Displays potent endoprotease activity against fibrinogen at acid pH. May play an important role in extracellular matrix degradation

Enzyme Numbers (IUBMB) for CTSK Gene

Gene Ontology (GO) - Molecular Function for CTSK Gene

GO ID Qualified GO term Evidence PubMed IDs
GO:0001968 fibronectin binding IPI 22952693
GO:0004197 cysteine-type endopeptidase activity IDA 22952693
GO:0005515 protein binding IPI 12504904
GO:0005518 collagen binding IDA 22952693
GO:0008234 cysteine-type peptidase activity TAS 7818555
genes like me logo Genes that share ontologies with CTSK: view
genes like me logo Genes that share phenotypes with CTSK: view

Animal Models for CTSK Gene

MGI Knock Outs for CTSK:

Animal Model Products

miRNA for CTSK Gene

miRTarBase miRNAs that target CTSK

miRNA Products

Inhibitory RNA Products

  • Predesigned siRNA for gene silencing in human,mouse,rat for CTSK

In Situ Assay Products

Flow Cytometry Products

No data available for Transcription Factor Targets and HOMER Transcription for CTSK Gene

Localization for CTSK Gene

Subcellular locations from UniProtKB/Swiss-Prot for CTSK Gene


Subcellular locations from

Jensen Localization Image for CTSK Gene COMPARTMENTS Subcellular localization image for CTSK gene
Compartment Confidence
lysosome 5
vacuole 5
endosome 4
extracellular 4
cytoskeleton 2
nucleus 2
plasma membrane 2
cytosol 1

Gene Ontology (GO) - Cellular Components for CTSK Gene

GO ID Qualified GO term Evidence PubMed IDs
GO:0005576 extracellular region TAS --
GO:0005615 extracellular space IDA 22952693
GO:0005737 cytoplasm --
GO:0005764 lysosome IBA --
GO:0036021 endolysosome lumen TAS --
genes like me logo Genes that share ontologies with CTSK: view

Pathways & Interactions for CTSK Gene

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

PCR Array Products

Gene Ontology (GO) - Biological Process for CTSK Gene

GO ID Qualified GO term Evidence PubMed IDs
GO:0001957 intramembranous ossification IEA --
GO:0002224 toll-like receptor signaling pathway TAS --
GO:0006508 proteolysis TAS 7818555
GO:0022617 extracellular matrix disassembly TAS --
GO:0030198 extracellular matrix organization TAS --
genes like me logo Genes that share ontologies with CTSK: view

No data available for SIGNOR curated interactions for CTSK Gene

Drugs & Compounds for CTSK Gene

(41) Drugs for CTSK Gene - From: NovoSeek, DrugBank, ApexBio, DGIdb, and Tocris

Name Status Disease Links Group Role Mechanism of Action Clinical Trials
Aprotinin Approved, Withdrawn Pharma Inhibitor of bovine pancreatic trypsin 24
chloroquine Approved Pharma Agonist 137
Teriparatide Approved, Investigational Pharma 128

(23) Additional Compounds for CTSK Gene - From: NovoSeek and Tocris

Name Synonyms Role CAS Number PubChem IDs PubMed IDs
L 006235
SID 26681509
genes like me logo Genes that share compounds with CTSK: view

Drug Products

Transcripts for CTSK Gene

mRNA/cDNA for CTSK Gene

Unigene Clusters for CTSK Gene

Cathepsin K:
Representative Sequences:

miRNA Products

Inhibitory RNA Products

  • Predesigned siRNA for gene silencing in human,mouse,rat for CTSK

Flow Cytometry Products

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

ExUns: 1 ^ 2a · 2b · 2c ^ 3 ^ 4a · 4b · 4c ^ 5 ^ 6a · 6b ^ 7a · 7b ^ 8a · 8b ^ 9 ^ 10
SP1: -
SP2: -
SP3: - - - -
SP4: -
SP6: -

Relevant External Links for CTSK Gene

GeneLoc Exon Structure for
ECgene alternative splicing isoforms for

Expression for CTSK Gene

mRNA expression in normal human tissues for CTSK Gene

mRNA expression in embryonic tissues and stem cells from LifeMap Discovery

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

This gene is overexpressed in Cervix - Ectocervix (x5.7) and Cervix - Endocervix (x4.7).

Protein differential expression in normal tissues from HIPED for CTSK Gene

This gene is overexpressed in Heart (69.0).

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

SOURCE GeneReport for Unigene cluster for CTSK Gene Hs.632466

mRNA Expression by UniProt/SwissProt for CTSK Gene

Tissue specificity: Predominantly expressed in osteoclasts (bones)
genes like me logo Genes that share expression patterns with CTSK: view

Protein tissue co-expression partners for CTSK Gene

- Elite partner

Primer Products

In Situ Assay Products

Orthologs for CTSK Gene

This gene was present in the common ancestor of eukaryotes.

Orthologs for CTSK Gene

Organism Taxonomy Gene Similarity Type Details
(Bos Taurus)
Mammalia CTSK 35
  • 93.41 (n)
  • 95.74 (a)
  • 94 (a)
(Canis familiaris)
Mammalia CTSK 35
  • 93.31 (n)
  • 95.44 (a)
  • 94 (a)
(Mus musculus)
Mammalia Ctsk 35
  • 87.13 (n)
  • 86.02 (a)
Ctsk 16
Ctsk 36
  • 86 (a)
(Pan troglodytes)
Mammalia CTSK 35
  • 99.59 (n)
  • 98.78 (a)
  • 99 (a)
(Rattus norvegicus)
Mammalia Ctsk 35
  • 87.54 (n)
  • 87.54 (a)
(Monodelphis domestica)
Mammalia CTSK 36
  • 87 (a)
(Ornithorhynchus anatinus)
Mammalia CTSK 36
  • 81 (a)
(Gallus gallus)
Aves CTSK 35
  • 66.56 (n)
  • 72.36 (a)
  • 71 (a)
(Anolis carolinensis)
Reptilia CTSK 36
  • 85 (a)
tropical clawed frog
(Silurana tropicalis)
Amphibia ctsk 35
  • 68.42 (n)
  • 70.59 (a)
(Danio rerio)
Actinopterygii ctsk 35
  • 65.58 (n)
  • 65.36 (a)
wufb08b05 35
ctsk 36
  • 60 (a)
fruit fly
(Drosophila melanogaster)
Insecta 26-29kD-proteinase 37
  • 39 (a)
CG11459 37
  • 35 (a)
CG4847 37
  • 39 (a)
Cp1 37
  • 47 (a)
(Caenorhabditis elegans)
Secernentea cpl-1 37
  • 46 (a)
R07E3.1 37
  • 37 (a)
R09F10.1 37
  • 32 (a)
(Oryza sativa)
Liliopsida Os11g0255300 35
  • 50.8 (n)
  • 44.73 (a)
Species with no ortholog for CTSK:
  • 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)
  • 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)
  • 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)
  • orangutan (Pongo pygmaeus)
  • pig (Sus scrofa)
  • rainbow trout (Oncorhynchus mykiss)
  • 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)
  • wheat (Triticum aestivum)

Evolution for CTSK Gene

Gene Tree for CTSK (if available)
Gene Tree for CTSK (if available)

Paralogs for CTSK Gene

Paralogs for CTSK Gene

(8) SIMAP similar genes for CTSK Gene using alignment to 5 proteins:

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

Variants for CTSK Gene

Sequence variations from dbSNP and Humsavar for CTSK Gene

SNP ID Clin Chr 01 pos Sequence Context AA Info Type MAF
rs11958 -- 150,796,282(-) GTCTT(A/C)CCTTC utr-variant-3-prime
rs1063586 -- 150,796,668(-) TCAGT(A/T)TCCCC utr-variant-3-prime
rs1241367 -- 150,805,445(+) gacca(G/T)cctgg intron-variant
rs1272967 -- 150,805,484(+) aaata(C/G)aaaaa intron-variant
rs1802666 -- 150,796,356(-) GTTTT(A/C)TACTC utr-variant-3-prime

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

Variant ID Type Subtype PubMed ID
nsv872418 CNV Gain 21882294
nsv437169 CNV Loss 16327808
nsv2788 CNV Loss 18451855
nsv2799 CNV Insertion 18451855
nsv160180 CNV Loss 16902084

Variation tolerance for CTSK Gene

Residual Variation Intolerance Score: 40.22% of all genes are more intolerant (likely to be disease-causing)
Gene Damage Index Score: 0.57; 12.34% of all genes are more intolerant (likely to be disease-causing)

Relevant External Links for CTSK Gene

HapMap Linkage Disequilibrium report
Human Gene Mutation Database (HGMD)

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

Disorders for CTSK Gene

MalaCards: The human disease database

(22) MalaCards diseases for CTSK Gene - From: OMIM, ClinVar, GeneTests, Orphanet, Swiss-Prot, DISEASES, NovoSeek, and GeneCards

Disorder Aliases PubMed IDs
  • pknd
kindler syndrome
  • bullous acrokeratotic poikiloderma of kindler and weary
intermediate osteopetrosis
  • autosomal recessive intermediate osteopetrosis
root resorption
- elite association
Search CTSK in MalaCards View complete list of genes associated with diseases


  • Pycnodysostosis (PKND) [MIM:265800]: A rare autosomal recessive bone disorder characterized by deformity of the skull, maxilla and phalanges, osteosclerosis, and fragility of bone. {ECO:0000269 PubMed:10491211, ECO:0000269 PubMed:10878663, ECO:0000269 PubMed:8703060, ECO:0000269 PubMed:9529353}. Note=The disease is caused by mutations affecting the gene represented in this entry.

Relevant External Links for CTSK

Genetic Association Database (GAD)
Human Genome Epidemiology (HuGE) Navigator
Atlas of Genetics and Cytogenetics in Oncology and Haematology:
genes like me logo Genes that share disorders with CTSK: view

No data available for Genatlas for CTSK Gene

Publications for CTSK Gene

  1. Molecular cloning of human cDNA for cathepsin K: novel cysteine proteinase predominantly expressed in bone. (PMID: 7818555) Inaoka T. … Kokubo T. (Biochem. Biophys. Res. Commun. 1995) 2 23 67
  2. A single nucleotide polymorphism in the porcine cathepsin K (CTSK) gene is associated with back fat thickness and production traits in Italian Duroc pigs. (PMID: 19662513) Fontanesi L. … Russo V. (Mol. Biol. Rep. 2010) 23 67
  3. Detection of femtomole quantities of mature cathepsin K with zymography. (PMID: 20206119) Li W.A. … Platt M.O. (Anal. Biochem. 2010) 23 67
  4. Human macrophage foam cells degrade atherosclerotic plaques through cathepsin K mediated processes. (PMID: 20409295) Barascuk N. … Karsdal M.A. (BMC Cardiovasc Disord 2010) 23 67
  5. Cathepsin K gene disruption does not affect murine aneurysm formation. (PMID: 19775691) Bai L. … Heeneman S. (Atherosclerosis 2010) 23 67

Products for CTSK Gene

Sources for CTSK Gene

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