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http://purl.uniprot.org/citations/20036517http://www.w3.org/1999/02/22-rdf-syntax-ns#typehttp://purl.uniprot.org/core/Journal_Citation
http://purl.uniprot.org/citations/20036517http://www.w3.org/2000/01/rdf-schema#comment"

Objective

Elevated plasma total homocysteine (tHcy) is a risk factor for a variety of human diseases. Homocysteine is formed from methionine and has two primary metabolic fates: remethylation to form methionine or commitment to the transsulfuration pathway by the action of cystathionine β-synthase (CBS). We have examined the metabolic response in mice of a shift from a methionine-replete to a methionine-free diet.

Methods and results

We found that shifting 3-mo-old C57BL6 mice to a methionine-free diet caused a transient increase in tHcy and an increase in the tHcy/methionine ratio. Because CBS is a key regulator of tHcy, we examined CBS protein levels and found that within 3 d on the methionine-deficient diet, animals had a 50% reduction in the levels of liver CBS protein and enzyme activity. Examination of CBS mRNA and studies of transgenic animals that express CBS from a heterologous promoter indicated that this reduction is occurring post-transcriptionally. Loss of CBS protein was unrelated to intracellular levels of S-adenosylmethionine, a known regulator of CBS activity and stability.

Conclusion

Our results imply that methionine deprivation induces a metabolic state in which methionine is effectively conserved in tissue by shutdown of the transsulfuration pathway by an S-adenosylmethionine-independent mechanism that signals a rapid downregulation of CBS protein."xsd:string
http://purl.uniprot.org/citations/20036517http://purl.org/dc/terms/identifier"doi:10.1016/j.nut.2009.10.006"xsd:string
http://purl.uniprot.org/citations/20036517http://purl.uniprot.org/core/author"Gupta S."xsd:string
http://purl.uniprot.org/citations/20036517http://purl.uniprot.org/core/author"Tang B."xsd:string
http://purl.uniprot.org/citations/20036517http://purl.uniprot.org/core/author"Mustafa A."xsd:string
http://purl.uniprot.org/citations/20036517http://purl.uniprot.org/core/author"Kruger W.D."xsd:string
http://purl.uniprot.org/citations/20036517http://purl.uniprot.org/core/author"James S.J."xsd:string
http://purl.uniprot.org/citations/20036517http://purl.uniprot.org/core/author"Melnyk S."xsd:string
http://purl.uniprot.org/citations/20036517http://purl.uniprot.org/core/date"2010"xsd:gYear
http://purl.uniprot.org/citations/20036517http://purl.uniprot.org/core/name"Nutrition"xsd:string
http://purl.uniprot.org/citations/20036517http://purl.uniprot.org/core/pages"1170-1175"xsd:string
http://purl.uniprot.org/citations/20036517http://purl.uniprot.org/core/title"Methionine-deficient diet induces post-transcriptional downregulation of cystathionine beta-synthase."xsd:string
http://purl.uniprot.org/citations/20036517http://purl.uniprot.org/core/volume"26"xsd:string
http://purl.uniprot.org/citations/20036517http://www.w3.org/2004/02/skos/core#exactMatchhttp://purl.uniprot.org/pubmed/20036517
http://purl.uniprot.org/citations/20036517http://xmlns.com/foaf/0.1/primaryTopicOfhttps://pubmed.ncbi.nlm.nih.gov/20036517
http://purl.uniprot.org/uniprot/#_Q91WT9-mappedCitation-20036517http://www.w3.org/1999/02/22-rdf-syntax-ns#objecthttp://purl.uniprot.org/citations/20036517
http://purl.uniprot.org/uniprot/Q91WT9http://purl.uniprot.org/core/mappedCitationhttp://purl.uniprot.org/citations/20036517