CTH - Cystathionine gamma-lyase - human protein (Function)
 
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Protein
Gene
References

 
CTH »  Cystathionine gamma-lyase   [ EC 4.4.1.1 ]
 
Protein also known as:  Cysteine-protein sulfhydrase.
Gene name:  CTH
Entry whose protein(s) existence is based on evidence at protein level
extend overview
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GENE REF ISO

Function

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Overview 
Catalyzes the last step in the trans-sulfuration pathway from methionine to cysteine. Has broad substrate specificity. Converts cystathionine to cysteine, ammonia and 2-oxobutanoate. Converts two cysteine molecules to lanthionine and hydrogen sulfide. Can also accept homocysteine as substrate. Specificity depends on the levels of the endogenous substrates. Generates the endogenous signaling molecule hydrogen sulfide (H2S), and so contributes to the regulation of blood pressure. Acts as a cysteine-protein sulfhydrase by mediating sulfhydration of target proteins: sulfhydration consists of converting -SH groups into -SSH on specific cysteine residues of target proteins such as GAPDH, PTPN1 and NF-kappa-B subunit RELA, thereby regulating their function.  
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  • UniProtKB
GO molecular function 
Calmodulin bindingdefinition[GO:0005516]  
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  • UniProtKB KW
Cystathionine gamma-lyase activitydefinition[GO:0004123]  
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  • UniProtKB
L-cystine L-cysteine-lyase (deaminating)definition[GO:0044540]  
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  • UniProtKB
Protein bindingdefinition[GO:0005515]  
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  • IntAct
  • UniProtKB
Pyridoxal phosphate bindingdefinition[GO:0030170]  
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  • UniProtKB
GO biological process 
Cysteine biosynthetic processdefinition[GO:0019344]  
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  • UniProtKB
  • UniPathway
Cysteine metabolic processdefinition[GO:0006534]  
1
  • PINC
Endoplasmic reticulum unfolded protein responsedefinition[GO:0030968]  
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  • UniProtKB
Hydrogen sulfide biosynthetic processdefinition[GO:0070814]  
1
  • UniProtKB
Negative regulation of apoptotic signaling pathwaydefinition[GO:2001234] silver  
1
  • Ortholog Compara
Positive regulation of I-kappaB kinase/NF-kappaB signalingdefinition[GO:0043123] silver  
1
  • Ortholog Compara
Positive regulation of NF-kappaB transcription factor activitydefinition[GO:0051092] silver  
1
  • Ortholog Compara
Protein homotetramerizationdefinition[GO:0051289]  
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  • UniProtKB
Protein sulfhydrationdefinition[GO:0044524]  
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  • UniProtKB
Protein-pyridoxal-5-phosphate linkage via peptidyl-N6-pyridoxal phosphate-L-lysinedefinition[GO:0018272]  
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  • UniProtKB
Enzymatic activity 
This protein acts as an enzyme. It is known to catalyze the following reaction
EC 4.4.1.1: L-cystathionine + H(2)O L-cysteine + NH(3) + 2-oxobutanoate.  
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  • UniProtKB
It requires the following cofactor
 pyridoxal 5'-phosphate  
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  • UniProtKB
It is regulated in the following manner
Inhibited by propargylglycine, trifluoroalanine and aminoethoxyvinylglycine.  
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  • UniProtKB
 
More information is available from:
Pathways 
This protein is involved in the following pathway
Amino-acid biosynthesis; L-cysteine biosynthesis; L-cysteine from L-homocysteine and L-serine: step 2/2  
1
  • UniProtKB
According to KEGG, this protein belongs to the following pathways:
Cysteine and methionine metabolism  hsa00270+1491  
Glycine, serine and threonine metabolism  hsa00260+1491  
Metabolic pathways  hsa01100+1491  
Nitrogen metabolism  hsa00910+1491  
Selenocompound metabolism  hsa00450+1491  
According to Reactome, this protein belongs to the following pathways:
Cysteine formation from homocysteine  REACT_115589  
Degradation of cysteine and homocysteine  REACT_115654  
 
More information is available from:
 

Biophysicochemical properties

Kinetic parameters
KM 0.5 mM for L-cystathionine
KM 5.4 mM for homocysteine
KM 3.5 mM for cysteine
Dependence
pH Optimum pH is 8.2.

Keywords

Biological process 
Amino-acid biosynthesis  definition   [KW-0028]
Cysteine biosynthesis  definition   [KW-0198]
Molecular function 
Lyase  definition   [KW-0456]
Technical term 
Reference proteome  definition   [KW-1185]
 

Further external links

Enzyme and pathway databases
SABIO-RK: P32929
Other
GenomeRNAi: 1491
PRO: PR:P32929
Chemistry
GuidetoPHARMACOLOGY: 1444