CTSA Gene

HGNC Family	Cathepsins (CTS)
Name	cathepsin A
Description	This gene encodes a member of the peptidase S10 family of serine carboxypeptidases. Alternative splicing results in multiple transcript variants, at least one of which encodes a preproprotein that is proteolytically processed to generate two chains that comprise the heterodimeric active enzyme. This enzyme possesses deamidase, esterase and carboxypeptidase activities and acts as a scaffold in the lysosomal multienzyme complex. Mutations in this gene are associated with galactosialidosis. [provided by RefSeq, Nov 2015]
Summary	{"type": "root", "children": [{"type": "p", "children": [{"type": "t", "text": "\n Cathepsin A (CTSA), also known as the protective protein/cathepsin A (PPCA), is a multifunctional lysosomal enzyme that plays a critical chaperone role by associating with other lysosomal hydrolases. In its well‐characterized function within the multienzyme complex, CTSA is essential for the proper activation and stabilization of neuraminidase‐1 (Neu1) and β‐galactosidase, thereby safeguarding them against premature degradation and ensuring efficient lysosomal catabolism of sialoglycoconjugates."}, {"type": "fg", "children": [{"type": "fg_fs", "start_ref": "1", "end_ref": "3"}]}, {"type": "t", "text": " \n This CTSA-mediated stabilization is not only vital for intracellular substrate degradation but also for extracellular events. For example, on the cell surface, CTSA forms a complex with the elastin-binding protein (EBP) and Neu1, where its associated sialidase activity is required for the desialylation and subsequent release of tropoelastin, thereby facilitating elastic fiber assembly and proper extracellular matrix organization. Moreover, CTSA contributes to the inactivation of vasoactive peptides such as endothelin-1, linking its activity to vascular homeostasis and elastic fiber formation."}, {"type": "fg", "children": [{"type": "fg_f", "ref": "1"}]}, {"type": "t", "text": " \n Recent findings further suggest a broader regulatory role for CTSA, wherein its interaction with proteins involved in lysosomal trafficking—such as sorting nexin 10—modulates the stability of key autophagy effectors like LAMP-2A, thus impacting chaperone-mediated autophagy and cellular responses to stress."}, {"type": "fg", "children": [{"type": "fg_f", "ref": "4"}]}, {"type": "t", "text": " \n In summary, CTSA functions as a central regulator of lysosomal enzyme activity and extracellular matrix remodeling by ensuring the proper activation of Neu1 and related enzymes—activities that are critical for both intracellular catabolism and the control of extracellular events such as elastogenesis and vascular tone.\n "}]}, {"type": "rg", "children": [{"type": "r", "ref": 1, "children": [{"type": "t", "text": "Aleksander Hinek, Alexey V Pshezhetsky, Mark von Itzstein, et al. "}, {"type": "b", "children": [{"type": "t", "text": "Lysosomal sialidase (neuraminidase-1) is targeted to the cell surface in a multiprotein complex that facilitates elastic fiber assembly."}]}, {"type": "t", "text": " "}, {"type": "i", "children": [{"type": "t", "text": "J Biol Chem (2006)"}]}, {"type": "t", "text": " DOI: "}, {"type": "a", "children": [{"type": "t", "text": "10.1074/jbc.M508736200"}], "href": "https://doi.org/10.1074/jbc.M508736200"}, {"type": "t", "text": " PMID: "}, {"type": "a", "children": [{"type": "t", "text": "16314420"}], "href": "https://pubmed.ncbi.nlm.nih.gov/16314420"}]}, {"type": "r", "ref": 2, "children": [{"type": "t", "text": "Volkan Seyrantepe, Aleksander Hinek, Junzheng Peng, et al. "}, {"type": "b", "children": [{"type": "t", "text": "Enzymatic activity of lysosomal carboxypeptidase (cathepsin) A is required for proper elastic fiber formation and inactivation of endothelin-1."}]}, {"type": "t", "text": " "}, {"type": "i", "children": [{"type": "t", "text": "Circulation (2008)"}]}, {"type": "t", "text": " DOI: "}, {"type": "a", "children": [{"type": "t", "text": "10.1161/CIRCULATIONAHA.107.733212"}], "href": "https://doi.org/10.1161/CIRCULATIONAHA.107.733212"}, {"type": "t", "text": " PMID: "}, {"type": "a", "children": [{"type": "t", "text": "18391110"}], "href": "https://pubmed.ncbi.nlm.nih.gov/18391110"}]}, {"type": "r", "ref": 3, "children": [{"type": "t", "text": "Erik J Bonten, Yvan Campos, Viateslav Zaitsev, et al. "}, {"type": "b", "children": [{"type": "t", "text": "Heterodimerization of the sialidase NEU1 with the chaperone protective protein/cathepsin A prevents its premature oligomerization."}]}, {"type": "t", "text": " "}, {"type": "i", "children": [{"type": "t", "text": "J Biol Chem (2009)"}]}, {"type": "t", "text": " DOI: "}, {"type": "a", "children": [{"type": "t", "text": "10.1074/jbc.M109.031419"}], "href": "https://doi.org/10.1074/jbc.M109.031419"}, {"type": "t", "text": " PMID: "}, {"type": "a", "children": [{"type": "t", "text": "19666471"}], "href": "https://pubmed.ncbi.nlm.nih.gov/19666471"}]}, {"type": "r", "ref": 4, "children": [{"type": "t", "text": "Yan You, Wan-Zhen Li, Sulin Zhang, et al. "}, {"type": "b", "children": [{"type": "t", "text": "SNX10 mediates alcohol-induced liver injury and steatosis by regulating the activation of chaperone-mediated autophagy."}]}, {"type": "t", "text": " "}, {"type": "i", "children": [{"type": "t", "text": "J Hepatol (2018)"}]}, {"type": "t", "text": " DOI: "}, {"type": "a", "children": [{"type": "t", "text": "10.1016/j.jhep.2018.01.038"}], "href": "https://doi.org/10.1016/j.jhep.2018.01.038"}, {"type": "t", "text": " PMID: "}, {"type": "a", "children": [{"type": "t", "text": "29452206"}], "href": "https://pubmed.ncbi.nlm.nih.gov/29452206"}]}]}]}
Synonyms	GLB2, PPGB, PPCA, NGBE, GSL
Proteins	PPGB_HUMAN
NCBI Gene ID	5476
API
Download Associations
Predicted Functions
Co-expressed Genes
Expression in Tissues and Cell Lines

Functional Associations

CTSA has 11,837 functional associations with biological entities spanning 9 categories (molecular profile, organism, chemical, disease, phenotype or trait, functional term, phrase or reference, structural feature, cell line, cell type or tissue, gene, protein or microRNA, sequence feature) extracted from 131 datasets.

Click the + buttons to view associations for CTSA from the datasets below.

If available, associations are ranked by standardized value

Harmonizome 3.0

CTSA Gene

Functional Associations

Please acknowledge the Harmonizome in your publications by citing the following reference(s):

	Dataset	Summary
	Achilles Cell Line Gene Essentiality Profiles	cell lines with fitness changed by CTSA gene knockdown relative to other cell lines from the Achilles Cell Line Gene Essentiality Profiles dataset.
	Allen Brain Atlas Adult Human Brain Tissue Gene Expression Profiles	tissues with high or low expression of CTSA gene relative to other tissues from the Allen Brain Atlas Adult Human Brain Tissue Gene Expression Profiles dataset.
	Allen Brain Atlas Adult Mouse Brain Tissue Gene Expression Profiles	tissues with high or low expression of CTSA gene relative to other tissues from the Allen Brain Atlas Adult Mouse Brain Tissue Gene Expression Profiles dataset.
	Allen Brain Atlas Aging Dementia and Traumatic Brain Injury Tissue Sample Gene Expression Profiles	tissue samples with high or low expression of CTSA gene relative to other tissue samples from the Allen Brain Atlas Aging Dementia and Traumatic Brain Injury Tissue Sample Gene Expression Profiles dataset.
	Allen Brain Atlas Developing Human Brain Tissue Gene Expression Profiles by Microarray	tissue samples with high or low expression of CTSA gene relative to other tissue samples from the Allen Brain Atlas Developing Human Brain Tissue Gene Expression Profiles by Microarray dataset.
	Allen Brain Atlas Developing Human Brain Tissue Gene Expression Profiles by RNA-seq	tissue samples with high or low expression of CTSA gene relative to other tissue samples from the Allen Brain Atlas Developing Human Brain Tissue Gene Expression Profiles by RNA-seq dataset.
	Allen Brain Atlas Prenatal Human Brain Tissue Gene Expression Profiles	tissues with high or low expression of CTSA gene relative to other tissues from the Allen Brain Atlas Prenatal Human Brain Tissue Gene Expression Profiles dataset.
	BioGPS Cell Line Gene Expression Profiles	cell lines with high or low expression of CTSA gene relative to other cell lines from the BioGPS Cell Line Gene Expression Profiles dataset.
	BioGPS Human Cell Type and Tissue Gene Expression Profiles	cell types and tissues with high or low expression of CTSA gene relative to other cell types and tissues from the BioGPS Human Cell Type and Tissue Gene Expression Profiles dataset.
	BioGPS Mouse Cell Type and Tissue Gene Expression Profiles	cell types and tissues with high or low expression of CTSA gene relative to other cell types and tissues from the BioGPS Mouse Cell Type and Tissue Gene Expression Profiles dataset.
	Carcinogenome Chemical Perturbation Carcinogenicity Signatures	small molecule perturbations changing expression of CTSA gene from the Carcinogenome Chemical Perturbation Carcinogenicity Signatures dataset.
	CCLE Cell Line Gene CNV Profiles	cell lines with high or low copy number of CTSA gene relative to other cell lines from the CCLE Cell Line Gene CNV Profiles dataset.
	CCLE Cell Line Gene Expression Profiles	cell lines with high or low expression of CTSA gene relative to other cell lines from the CCLE Cell Line Gene Expression Profiles dataset.
	CCLE Cell Line Proteomics	Cell lines associated with CTSA protein from the CCLE Cell Line Proteomics dataset.
	CellMarker Gene-Cell Type Associations	cell types associated with CTSA gene from the CellMarker Gene-Cell Type Associations dataset.
	ChEA Transcription Factor Binding Site Profiles	transcription factor binding site profiles with transcription factor binding evidence at the promoter of CTSA gene from the CHEA Transcription Factor Binding Site Profiles dataset.
	ChEA Transcription Factor Targets	transcription factors binding the promoter of CTSA gene in low- or high-throughput transcription factor functional studies from the CHEA Transcription Factor Targets dataset.
	ChEA Transcription Factor Targets 2022	transcription factors binding the promoter of CTSA gene in low- or high-throughput transcription factor functional studies from the CHEA Transcription Factor Targets 2022 dataset.
	ClinVar Gene-Phenotype Associations	phenotypes associated with CTSA gene from the curated ClinVar Gene-Phenotype Associations dataset.
	ClinVar Gene-Phenotype Associations 2025	phenotypes associated with CTSA gene from the curated ClinVar Gene-Phenotype Associations 2025 dataset.
	CM4AI U2OS Cell Map Protein Localization Assemblies	assemblies containing CTSA protein from integrated AP-MS and IF data from the CM4AI U2OS Cell Map Protein Localization Assemblies dataset.
	CMAP Signatures of Differentially Expressed Genes for Small Molecules	small molecule perturbations changing expression of CTSA gene from the CMAP Signatures of Differentially Expressed Genes for Small Molecules dataset.
	COMPARTMENTS Curated Protein Localization Evidence Scores	cellular components containing CTSA protein from the COMPARTMENTS Curated Protein Localization Evidence Scores dataset.
	COMPARTMENTS Curated Protein Localization Evidence Scores 2025	cellular components containing CTSA protein from the COMPARTMENTS Curated Protein Localization Evidence Scores 2025 dataset.
	COMPARTMENTS Experimental Protein Localization Evidence Scores	cellular components containing CTSA protein in low- or high-throughput protein localization assays from the COMPARTMENTS Experimental Protein Localization Evidence Scores dataset.
	COMPARTMENTS Experimental Protein Localization Evidence Scores 2025	cellular components containing CTSA protein in low- or high-throughput protein localization assays from the COMPARTMENTS Experimental Protein Localization Evidence Scores 2025 dataset.
	COMPARTMENTS Text-mining Protein Localization Evidence Scores	cellular components co-occuring with CTSA protein in abstracts of biomedical publications from the COMPARTMENTS Text-mining Protein Localization Evidence Scores dataset.
	COMPARTMENTS Text-mining Protein Localization Evidence Scores 2025	cellular components co-occuring with CTSA protein in abstracts of biomedical publications from the COMPARTMENTS Text-mining Protein Localization Evidence Scores 2025 dataset.
	CORUM Protein Complexes	protein complexs containing CTSA protein from the CORUM Protein Complexes dataset.
	COSMIC Cell Line Gene CNV Profiles	cell lines with high or low copy number of CTSA gene relative to other cell lines from the COSMIC Cell Line Gene CNV Profiles dataset.
	COSMIC Cell Line Gene Mutation Profiles	cell lines with CTSA gene mutations from the COSMIC Cell Line Gene Mutation Profiles dataset.
	CTD Gene-Disease Associations	diseases associated with CTSA gene/protein from the curated CTD Gene-Disease Associations dataset.
	DeepCoverMOA Drug Mechanisms of Action	small molecule perturbations with high or low expression of CTSA protein relative to other small molecule perturbations from the DeepCoverMOA Drug Mechanisms of Action dataset.
	DepMap CRISPR Gene Dependency	cell lines with fitness changed by CTSA gene knockdown relative to other cell lines from the DepMap CRISPR Gene Dependency dataset.
	DISEASES Curated Gene-Disease Association Evidence Scores 2025	diseases involving CTSA gene from the DISEASES Curated Gene-Disease Association Evidence Scores 2025 dataset.
	DISEASES Experimental Gene-Disease Association Evidence Scores 2025	diseases associated with CTSA gene in GWAS datasets from the DISEASES Experimental Gene-Disease Assocation Evidence Scores 2025 dataset.
	DISEASES Text-mining Gene-Disease Association Evidence Scores	diseases co-occuring with CTSA gene in abstracts of biomedical publications from the DISEASES Text-mining Gene-Disease Assocation Evidence Scores dataset.
	DISEASES Text-mining Gene-Disease Association Evidence Scores 2025	diseases co-occuring with CTSA gene in abstracts of biomedical publications from the DISEASES Text-mining Gene-Disease Assocation Evidence Scores 2025 dataset.
	DisGeNET Gene-Disease Associations	diseases associated with CTSA gene in GWAS and other genetic association datasets from the DisGeNET Gene-Disease Associations dataset.
	DisGeNET Gene-Phenotype Associations	phenotypes associated with CTSA gene in GWAS and other genetic association datasets from the DisGeNET Gene-Phenoptype Associations dataset.