What is the role of Cystathionine beta-synthase?

What is the role of Cystathionine beta-synthase?

The cystathionine ß-synthase (CBS) is a critical enzyme in the transsulfuration pathway and is responsible for the synthesis of cystathionine from serine and homocysteine. Cystathionine is a precursor to amino acid cysteine. CBS is also responsible for generation of hydrogen sulfide (H2S) from cysteine.

What is CBS deficiency?

Abstract. Cystathionine beta-synthase (CBS) deficiency is a rare inherited disorder in the methionine catabolic pathway, in which the impaired synthesis of cystathionine leads to accumulation of homocysteine. Patients can present to many different specialists and diagnosis is often delayed.

How is CBS mutation treated?

People with homocystinuria due to CBS deficiency who do not respond to vitamin B6 are treated with a special, protein -restricted diet to help lower the amount of methionine and homocysteine in their bodies. In addition, they may be given supplements, such as vitamin B12, folate, and betaine.

Where is the CBS gene located?

Cystathionine beta synthase

Location (UCSC) Chr 21: 43.05 – 43.08 Mb Chr 17: 31.61 – 31.64 Mb
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What is homocysteine methyltransferase?

In enzymology, a homocysteine S-methyltransferase (EC is an enzyme that catalyzes the chemical reaction S-methylmethionine + L-homocysteine 2 L-methionine. Thus, the two substrates of this enzyme are S-methylmethionine and L-homocysteine, and it produces 2 molecules of L-methionine.

What is Cystathioninuria?

Cystathioninuria is an autosomal recessive disorder caused by cystathionine gamma-lyase deficiency. It is usually pyridoxine-dependent, but in very rare cases it may be non-dependent. It is generally considered to be a benign condition without pathogenic relevance.

What is the CBS enzyme?

The CBS gene provides instructions for making an enzyme called cystathionine beta-synthase. This enzyme acts in a chemical pathway and is responsible for using vitamin B6 to convert building block of proteins (amino acid) called homocysteine and serine to a molecule called cytathionine.

What is homocystinuria CBS related?

Homocystinuria (CBS-related) is an autosomal recessive disorder caused by pathogenic variants in the gene CBS, and while it is considered to be a pan-ethnic disorder, it is most commonly seen among those of Qatari and Caucasian ancestry.

What is CBS gene?

Is methionine synthase the same as homocysteine methyltransferase?

Methionine synthase also known as MS, MeSe, MTR is responsible for the regeneration of methionine from homocysteine. In humans it is encoded by the MTR gene (5-methyltetrahydrofolate-homocysteine methyltransferase).

What is Sam cycle?

SAM: S-adenosylmethionine. The reactions that produce, consume, and regenerate SAM are called the SAM cycle. In the first step of this cycle, the SAM-dependent methylases (EC 2.1. 1) that use SAM as a substrate produce S-adenosyl homocysteine as a product.

What is the role of cystathionine beta-synthase mutation in fibrotic disease?

Abundant expression of CBS, localized in renal tubular epithelial cells, was revealed in human and rat renal tissue, which correlated negatively with the progression of fibrotic disease. c.797 G>A (p.R266K) cystathionine beta-synthase mutation has a role in causing homocystinuria by affecting protein stability

What is cystathionine beta-synthase deficiency?

Mutation within the CBS gene is associated with the development of congenital heart disease. Proteins with seven novel and 20 known mutations detected in cystathionine beta-synthase (CBS) deficiency completely lack CBS catalytic activity.

What is the role of cystathionine beta-synthase in breast cancer?

The H2S-producing enzyme cystathionine beta-synthase (CBS), sustaining cellular bioenergetics in colorectal cancer cells, plays a role in the interplay between gasotransmitters. (Review) CBS expression is elevated in breast cancer. AdoMet binding significantly enhances CBS inhibition by carbon monoxide.

What is CBS cystathionine-beta-synthase?

CBS cystathionine-beta-synthase [ (human)] Summary. The protein encoded by this gene acts as a homotetramer to catalyze the conversion of homocysteine to cystathionine, the first step in the transsulfuration pathway. The encoded protein is allosterically activated by adenosyl-methionine and uses pyridoxal phosphate as a cofactor.