CTH Gene (Cystathionine Gamma-Lyase)
Key enzyme in the transsulfuration pathway, linking methionine metabolism to hydrogen sulfide production.
Gene Information Card
| Symbol | CTH |
|---|---|
| Full Name | Cystathionine Gamma-Lyase |
| Gene Type | Protein coding |
| Chromosomal Location | 1p31.1 |
| NCBI Gene ID | 1491 ncbi.nlm.nih.gov/gene/1491 |
| Ensembl ID | ENSG00000116761 |
| UniProt ID | P32929 |
| OMIM ID | 607823 |
| HGNC ID | 2501 |
| Aliases | CSE, cystathionase, cystathionine gamma-lyase |
Description
The CTH gene encodes cystathionine gamma-lyase, a pyridoxal phosphate-dependent enzyme that catalyzes the last step in the transsulfuration pathway, converting cystathionine to cysteine, alpha-ketobutyrate, and ammonia. It is also a major source of endogenous hydrogen sulfide (H2S), a gasotransmitter involved in vasodilation, neurotransmission, and cytoprotection. Mutations in CTH cause cystathioninuria (OMIM 219200) and are associated with altered H2S levels in various disorders.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Cystathioninuria | Loss-of-function mutations in CTH impair cystathionine cleavage, leading to accumulation and urinary excretion of cystathionine. | ClinVar, OMIM |
| Homocystinuria (secondary) | Deficient CTH activity can disrupt homocysteine remethylation, contributing to hyperhomocysteinemia. | OMIM |
| Hypertension | Reduced CTH expression and H2S production are linked to endothelial dysfunction and elevated blood pressure. | NCBI Gene, PubMed |
| Atherosclerosis | Impaired H2S synthesis from CTH deficiency promotes vascular inflammation and plaque formation. | PubMed |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Liver | 28.5 | High |
| Kidney | 18.2 | High |
| Pancreas | 12.1 | Medium |
| Brain | 5.3 | Low |
| Heart | 4.8 | Low |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| HepG2 | 32.1 | Hepatocyte line, high expression |
| HEK293 | 15.4 | Embryonic kidney, moderate expression |
| SH-SY5Y | 6.2 | Neuroblastoma, low expression |
| A549 | 8.7 | Lung carcinoma, low expression |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.940G>A (p.Gly314Ser) | Missense | Rare | Reduced enzyme activity, associated with cystathioninuria |
| c.1364T>C (p.Leu455Pro) | Missense | Rare | Loss of function, H2S production impaired |
| c.200C>T (p.Thr67Met) | Missense | <0.01% | Decreased stability and activity |
| c.1123A>G (p.Thr375Ala) | Missense | 0.02% | Likely benign, no functional impact |
Mutation functional classification
Loss of Function (LOF)
Most pathogenic CTH mutations reduce or abolish enzymatic activity, leading to cystathioninuria and decreased H2S production.
Gain of Function (GOF)
No gain-of-function mutations have been reported for CTH.
Dominant Negative (DN)
No dominant-negative effects have been described; cystathioninuria is typically autosomal recessive.
View complete mutation data：
Gene Ontology (GO)
| • cystathionine gamma-lyase activity | • pyridoxal phosphate binding |
| • hydrogen sulfide biosynthetic process | • transsulfuration |
| • cysteine biosynthetic process from homocysteine | • response to oxidative stress |
Pathways
• Transsulfuration pathway (Reactome: R-HSA-1614603)
• Hydrogen sulfide biosynthesis (KEGG: map00270)
• Cysteine and methionine metabolism (KEGG: map00270)
Protein Summary
Cystathionine gamma-lyase is a 405-amino acid homotetrameric enzyme that uses pyridoxal phosphate as a cofactor. It catalyzes the alpha,gamma-elimination of cystathionine to produce cysteine, alpha-ketobutyrate, and ammonia. Additionally, it generates hydrogen sulfide from cysteine and homocysteine. The enzyme is highly expressed in liver, kidney, and pancreas, and its activity is regulated by oxidative stress and post-translational modifications.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| CTHRC1 Knockout HEK293 Cell Line | EDJ-KQ2649 | Human | 115908 | Details Get a Quote |
| CTH Knockout HEK293 Cell Line | EDJ-KQ4382 | Human | 1491 | Details Get a Quote |
| CTHRC1 Knockout A-549 Cell Line | EDJ-KQ23416 | Human | 115908 | Details Get a Quote |
| CTHRC1 Knockout HCT 116 Cell Line | EDJ-KQ23417 | Human | 115908 | Details Get a Quote |
| CTH Knockout A-549 Cell Line | EDC07545 | Human | 1491 | Details Get a Quote |
| CTH Knockout HCT 116 Cell Line | EDJ-KQ26903 | Human | 1491 | Details Get a Quote |
| CTH Knockout HeLa Cell Line | EDJ-KQ26904 | Human | 1491 | Details Get a Quote |
| CTHRC1 Knockout HeLa Cell Line | EDJ-KQ57965 | Human | 115908 | Details Get a Quote |
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