CTSL

Protein identityUniProt · HPA

UniProt accession

P07711

Gene

CTSL

Ensembl

ENSG00000135047

Chromosome

9

Canonical length

333 aa

Protein class

Cancer-related genes, Enzymes, Metabolic proteins, Plasma proteins, Predicted intracellular proteins

Subcellular location

Golgi apparatus,Vesicles

Secretome location

Intracellular and membrane

OverviewNCBI Gene

The protein encoded by this gene is a lysosomal cysteine proteinase that plays a major role in intracellular protein catabolism. Its substrates include collagen and elastin, as well as alpha-1 protease inhibitor, a major controlling element of neutrophil elastase activity. The encoded protein has been implicated in several pathologic processes, including myofibril necrosis in myopathies and in myocardial ischemia, and in the renal tubular response to proteinuria. This protein, which is a member of the peptidase C1 family, is a dimer composed of disulfide-linked heavy and light chains, both produced from a single protein precursor. Additionally, this protein cleaves the S1 subunit of the SARS-CoV-2 spike protein, which is necessary for entry of the virus into the cell. [provided by RefSeq, Aug 2020]

Canonical amino-acid sequenceUniProt

333 residues, UniProt reviewed canonical sequence.

>P07711|CTSL
     1  MNPTLILAAF CLGIASATLT FDHSLEAQWT KWKAMHNRLY GMNEEGWRRA VWEKNMKMIE
    61  LHNQEYREGK HSFTMAMNAF GDMTSEEFRQ VMNGFQNRKP RKGKVFQEPL FYEAPRSVDW
   121  REKGYVTPVK NQGQCGSCWA FSATGALEGQ MFRKTGRLIS LSEQNLVDCS GPQGNEGCNG
   181  GLMDYAFQYV QDNGGLDSEE SYPYEATEES CKYNPKYSVA NDTGFVDIPK QEKALMKAVA
   241  TVGPISVAID AGHESFLFYK EGIYFEPDCS SEDMDHGVLV VGYGFESTES DNNKYWLVKN
   301  SWGEEWGMGG YVKMAKDRRN HCGIASAASY PTV

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against CTSL 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

Cell surface

Secreted

No

Transmembrane segments

0

Mean surface accessibility (rSASA)

0.26

Highest tissue expression

529 nTPM

Expression across tissuesHPA

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)

0.78

gnomAD pLI

0.01

gnomAD missense Z

0.36

DepMap mean gene effect

0

DepMap dependency class

selective

Cancer expressionTCGA

Across TCGA tumor cohorts, this protein is over-expressed in roughly 4% of surveyed tumor types (aggregate summary; per-cohort expression, alteration, and survival load in the interactive view).

OntologyGO

Biological processes

• adaptive immune response
• antigen processing and presentation
• antigen processing and presentation of exogenous peptide antigen via MHC class II
• antigen processing and presentation of peptide antigen
• CD4-positive, alpha-beta T cell lineage commitment
• cellular response to thyroid hormone stimulus
• collagen catabolic process
• elastin catabolic process
• enkephalin processing
• fusion of virus membrane with host plasma membrane
• macrophage apoptotic process
• protein autoprocessing
• proteolysis
• proteolysis involved in protein catabolic process
• receptor-mediated endocytosis of virus by host cell
• symbiont entry into host cell
• zymogen activation
• fusion of virus membrane with host endosome membrane

Molecular functions

• collagen binding
• cysteine-type endopeptidase activity
• cysteine-type peptidase activity
• fibronectin binding
• histone binding
• proteoglycan binding
• serpin family protein binding

Cellular components

• apical plasma membrane
• chromaffin granule
• endocytic vesicle lumen
• endolysosome lumen
• extracellular exosome
• extracellular matrix
• extracellular region
• extracellular space
• Golgi apparatus
• lysosomal lumen
• lysosome
• multivesicular body
• nucleus
• plasma membrane

Protein domainsUniProt · Pfam · InterPro

• Cysteine peptidase, cysteine active site
• Peptidase C1A, papain C-terminal
• Peptidase C1A
• Cathepsin propeptide inhibitor domain (I29)
• Cysteine peptidase, histidine active site
• Cysteine peptidase, asparagine active site
• Papain-like cysteine peptidase superfamily
• Papain-like cysteine endopeptidase
• Papain family cysteine protease
• Cathepsin propeptide inhibitor domain (I29)

KeywordsUniProt

• Alternative initiation
• Cell membrane
• Cytoplasmic vesicle
• Disulfide bond
• Glycoprotein
• Host-virus interaction
• Hydrolase
• Lysosome
• Membrane
• Nucleus
• Protease
• Secreted
• Signal
• Thiol protease
• Zymogen

InteractionsUniProt · HPA

Protein binding partners of CTSL in the human serome: UniProt-annotated complex subunits plus reported interactors. Each links to its own Seroatlas record.

• CSTA