Cysteine degradation gene yhaM, encoding cysteine desulfidase, serves as a genetic engineering target to improve cysteine production in Escherichia coli.

Cysteine is an important amino acid for various industries; however, there is no efficient microbial fermentation-based production method available. Owing to its cytotoxicity, bacterial intracellular levels of cysteine are stringently controlled via several modes of regulation, including cysteine degradation by cysteine desulfhydrases and cysteine desulfidases. In Escherichia coli, several metabolic enzymes are known to exhibit cysteine degradative activities, however, their specificity and physiological significance for cysteine detoxification via degradation are unclear.

Fermentative Production of Cysteine by Pantoea ananatis.

Cysteine is a commercially important amino acid; however, it lacks an efficient fermentative production method. Due to its cytotoxicity, intracellular cysteine levels are stringently controlled via several regulatory modes. Managing its toxic effects as well as understanding and deregulating the complexities of regulation are crucial for establishing the fermentative production of cysteine.

Bacterial Cysteine-Inducible Cysteine Resistance Systems.

Unlabelled: Cysteine donates sulfur to macromolecules and occurs naturally in many proteins. Because low concentrations of cysteine are cytotoxic, its intracellular concentration is stringently controlled. In bacteria, cysteine biosynthesis is regulated by feedback inhibition of the activities of serine acetyltransferase (SAT) and 3-phosphoglycerate dehydrogenase (3-PGDH) and is also regulated at the transcriptional level by inducing the cysteine regulon using the master regulator CysB.

Calreticulin is required for development of the cumulus oocyte complex and female fertility.

Calnexin (CANX) and calreticulin (CALR) chaperones mediate nascent glycoprotein folding in the endoplasmic reticulum. Here we report that these chaperones have distinct roles in male and female fertility. Canx null mice are growth retarded but fertile.

Induction of the Escherichia coli yijE gene expression by cystine.

Cystine is formed from two molecules of the cysteine under oxidized conditions, but is reversibly converted to cysteine by reduction. Growth of Escherichia coli is retarded in the presence of excess cystine. Transcriptome analysis showed 11 up-regulated and 26 down-regulated genes upon exposure to excess cystine.

Involvement of the yciW gene in l-cysteine and l-methionine metabolism in Escherichia coli.

We here analyzed a sulfur index of Escherichia coli using LC-MS/MS combined with thiol-specific derivatization by monobromobimane. The obtained sulfur index was then applied to evaluate the L-cysteine producer. E.

Enhancement of L-cysteine production by disruption of yciW in Escherichia coli.

Using in silico analysis, the yciW gene of Escherichia coli was identified as a novel L-cysteine regulon that may be regulated by the transcriptional activator CysB for sulfur metabolic genes. We found that overexpression of yciW conferred tolerance to L-cysteine, but disruption of yciW increased L-cysteine production in E. coli.

Disruption of ADAM3 impairs the migration of sperm into oviduct in mouse.

Sperm from four different gene-disrupted mouse lines (calmegin [Clgn], Adam1a, Adam2, and Ace) are known to have defective zona-binding ability. Moreover, it is also reported that the sperm from all of these mouse lines exhibit another common phenotype of impaired migration into oviduct despite the large number of sperm found in uterus after coitus. On the other hand, the sperm from the Adam3-disrupted mouse line was reported to have defects in binding ability to zona, but were able to move into the oviduct.

Targeted gene modification in mouse ES cells using integrase-defective lentiviral vectors.

Lentiviral vectors efficiently integrate into the host genome of both dividing and nondividing cells, and so they have been used for stable transgene expression in biological and biomedical studies. However, recent studies have highlighted the risk of insertional mutagenesis and subsequent oncogenesis. Here, we used an integrase-defective lentiviral (IDLV) vector to decrease the chance of random integration and examined the feasibility of lentiviral vector-mediated gene targeting into murine embryonic stem (ES) cells.