Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:2.5.1.47 (cysteine synthase)
 625 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The coding sequences of the cysE and cysK genes from Escherichia coli, which encode the enzymes of the cysteine biosynthetic pathway, namely, serine acetyltransferase (EC 2.3.1.30) and O-acetylserine sulfhydrylase (or cysteine synthase [EC 4.2.99.8]), were modified for expression in eukaryotic cells and introduced into murine L cells. A number of fusion genes comprising the cysE or cysK coding sequences joined to the promoter of the ovine metallothionein-Ia (MT-Ia) gene and various portions of the ovine growth hormone (GH) gene were prepared. Significant differences in the level of transcription were observed, depending on the amount and arrangement of the GH gene sequences used, the highest levels being obtained with the constructs MTCE10 and MTCK7, which contained only the GH 3' untranslated gene sequences. These two constructs were fused to produce the gene MTCEK1. In this single DNA sequence, each bacterial gene is under independent MT-Ia promoter control. Expression of the cysK sequence in this construct (MT-Ia promoter-cysE-3' GH sequence-MT-Ia promoter-cysK-3' GH sequence) was elevated compared with expression of the cysK gene in MTCK7. However, expression of the cysE sequence in MTCEK1 was only 40% of that of the cysE gene cloned into MTCE10. The double-promoter configuration, which enhances the expression of the second gene in MTCEK1, is proposed as a model for the modification of bacterial genes in general.
 ...
PMID:Introduction and expression of the bacterial genes cysE and cysK in eukaryotic cells. 768 85

Reduced signaling of the growth hormone (GH)/insulin-like growth factor-1(IGF-1)/insulin pathway is associated with extended life span in several species. Ames dwarf mice are GH and IGF-1 deficient and live 50-64% longer than wild-type littermates (males and females, respectively). Previously, we have shown that Ames mice exhibit elevated levels of antioxidative enzymes and lower oxidative damage. To further explore the relationship between GH and antioxidant expression, we administered GH or saline to dwarf mice and evaluated components of the glutathione (GSH) synthesis and degradation system. Growth hormone treatment significantly elevated kidney gamma-glutamyl-cysteine synthetase protein levels in 3- and 12-month-old dwarf mice. In contrast, the activity of the GSH degradation enzyme, gamma-glutamyl transpeptidase, was suppressed by GH administration in brain (P <.05), kidney (P <.01), heart (P <.005), and liver (P <.06). Activity levels of the detoxification enzyme, glutathione-S-transferase, were also suppressed in kidney tissues at 3 and 12 months of age and in 12-month-old dwarf liver tissues (P <.05). Taken together, the current results along with data from previous studies support a role for growth hormone in the regulation of antioxidative defense and, ultimately, life span in organisms with altered GH or IGF-1 signaling.
 ...
PMID:Growth hormone alters components of the glutathione metabolic pathway in Ames dwarf mice. 1524 35

Reduced signaling of the growth hormone (GH)/insulin-like growth factor-1(IGF-1)/insulin pathway is associated with extended life span in several species. Ames dwarf mice are GH and IGF-1 deficient and live 50-64% longer than wild type littermates (males and females, respectively). Previously, we have shown that Ames mice exhibit elevated levels of antioxidative enzymes and lower oxidative damage. To further explore the relationship between GH and antioxidant expression, we administered GH or saline to dwarf mice and evaluated components of the methionine and glutathione (GSH) metabolic pathways. Treatment of dwarf mice with GH significantly suppressed methionine adenosyltransferase (40 and 38%) and glycine-N-methyltransferase (44 and 43%) activities (in 3- and 12-month-old mice, respectively). Growth hormone treatment elevated kidney gamma-glutamyl-cysteine synthetase protein levels in 3- and 12-month-old dwarf mice. In contrast, the activity of the GSH degradation enzyme, gamma-glutamyl transpeptidase, was suppressed by GH administration in heart and liver. The activity of glutathione-S-transferase, an enzyme involved in detoxification, was also affected by GH treatment. Taken together, the current results along with data from previous studies support a role for growth hormone in the regulation of antioxidative defense and ultimately, life span in organisms with altered GH or IGF-1 signaling.
 ...
PMID:Growth hormone alters methionine and glutathione metabolism in Ames dwarf mice. 1566 25