Selected-GenAtlas references SOURCE GeneCards NCBI Gene Swiss-Prot Orphanet Ensembl
HGNC UniGene Nucleotide OMIM UCSC
Home Page
FLASH GENE
Symbol CBS contributors: mct - updated : 05-06-2016
HGNC name cystathionine-beta-synthase
HGNC id 1550
Corresponding disease
CBSD homocystinuria, cystathionine beta-synthase deficiency
Location 21q22.3      Physical location : 44.473.300 - 44.496.472
Synonym name
  • beta-thionase
  • serine sulfhydrase
  • methylcysteine synthase
  • Synonym symbol(s) HIP4
    EC.number 4.2.1.22
    DNA
    TYPE functioning gene
    STRUCTURE 22.74 kb     17 Exon(s)
    10 Kb 5' upstream gene genomic sequence study
    text structure five alternative exons
    MAPPING cloned Y linked Y status confirmed
    Map see COL6A2 , TFF1 , PFKL PFKL
    RNA
    TRANSCRIPTS type messenger
    text other alternative transcripts differing at their 5' ends and/or presence/absence of exon 15
    identificationnb exonstypebpproduct
    ProteinkDaAAspecific expressionYearPubmed
    17 initiation site 2609 60.5 551 - 1998 9790750
    - initiation site 2586 - 551 - 1998 9790750
    - - 2372 - 551 - 1998 9790750
    EXPRESSION
    Type
       expressed in (based on citations)
    organ(s)
    SystemOrgan level 1Organ level 2Organ level 3Organ level 4LevelPubmedSpeciesStageRna symbol
    Cardiovascularheart    
    Digestiveliver   highly
    Endocrineadrenal gland     Mus musculus
     pancreas   highly
    Nervousbrain    
    Visualeyelens   
    cell lineage
    cell lines
    fluid/secretion
    at STAGE
    physiological period fetal
    Text brain, liver, kidney
    PROTEIN
    PHYSICAL PROPERTIES
    STRUCTURE
    motifs/domains
  • catalytic domain of 409 AA in the N terminal
  • a regulatory domain of 142 AA at the C terminus
  • mono polymer homomer , tetramer
    HOMOLOGY
    interspecies ortholog to murine Cbs
    Homologene
    FAMILY
  • cysteine synthase/cystathionine beta-synthase family
  • CATEGORY enzyme
    SUBCELLULAR LOCALIZATION     intracellular
    intracellular,cytoplasm,cytosolic
    intracellular,nucleus,nucleolus
    basic FUNCTION
  • converting homocysteine to cystathionine, first step of the transsulfuration pathway
  • playing an essential role for female reproductive function
  • participates in the process of oocyte maturation
  • critical role in antioxidant and methylation metabolism
  • catalyzes the rate-limiting step in the transsulfuration pathway for the metabolism of homocysteine (Hcy) in the kidney
  • rate-limiting enzyme responsible for the de novo synthesis of cysteine
  • CBS and CTH are critical for maintenance of mitochondrial function and glucocorticoid production in adrenal cortex
  • key role for the H2S-generating enzymes CBS and CTH in pulmonary vascular development and homeostasis and in lung alveolarization
  • BHMT and CBS are major enzymes in the metabolism of plasma homocysteine (Hcy)
  • CELLULAR PROCESS
    PHYSIOLOGICAL PROCESS
    PATHWAY
    metabolism aminoacid
    signaling
    sulfur aminoacid
    a component
    INTERACTION
    DNA
    RNA
    small molecule metal binding, cofactor,
  • pyridoxal-phosphate
  • protein
  • huntingtin
  • cell & other
    REGULATION
    ASSOCIATED DISORDERS
    corresponding disease(s) CBSD
    related resource Cystathionebeta-synthetase
    Other morbid association(s)
    TypeGene ModificationChromosome rearrangementProtein expressionProtein Function
    constitutional     --over  
    is a cause of maternal obstetric complications such as preeclampsia, pregnancy loss
    constitutional       loss of function
    ischemia-reperfusion reduces the activity of CBS leading to Hcy accumulation in the kidney, which in turn contributes to renal injury
    tumoral     --low  
    in hepatocellular carcinoma and associated with poor prognosis
    Susceptibility
  • to neural tube defect (NTD) in association with MTHFR, but no evidence of association with NTD in Netherlands and U.K
  • to the development of premature occlusive arterial disease
  • to cleft lip and palate
  • to intracranial aneurysms
  • Variant & Polymorphism SNP
  • 699 C>T,1080C>T, maybe involved in plasma homocysteine levels
  • insertion c844ins68 associated with cleft lip and palate
  • olymorphisms of homocysteine metabolism are possible risk factors for the formation of intracranial aneurysms (
  • Candidate gene
    Marker
  • lower levels of BHMT and CBS methylation are all predictors of failure in folic acid therapy for HHCY (hyperhomocysteinemia)
  • Therapy target
    SystemTypeDisorderPubmed
    metabolismamino acids 
    chemical chaperones present during the initial folding process can facilitate proper folding of several mutant CBS proteins and suggest it may be possible to treat some inborn errors of metabolism with agents that enhance proper protein folding
    ANIMAL & CELL MODELS
  • CBS deficient TgI278T Cbs(-/-) mice have significantly decreased fat mass and tCys compared to heterozygous sibling mice
  • mice with methionine-deficient diet, had a 50p100 reduction in the levels of liver CBS protein and enzyme activity, because diet induces post-transcriptional downregulation of Cbs