Disease relevance of Ass

• BACKGROUND and PURPOSE: Previous studies have shown that the ss-amyloid precursor protein (ssAPP) is upregulated after cerebral ischemia and that the ss-amyloid (Ass) fragment may be toxic to brain cells [1].
• Regulation of glucocorticoids of arginase and argininosuccinate synthetase in cultured rat hepatoma cells [2].
• In this study, we evaluated the influence of hypobaric hypoxia on the expression of NOS isoforms, argininosuccinate synthetase (AS), argininosuccinate lyase (AL), and manganese superoxide dismutase (Mn SOD) in the ventilatory muscles [3].
• Hyperammonemia: regulation of argininosuccinate synthetase and argininosuccinate lyase genes in aggregating cell cultures of fetal rat brain [4].
• The enzymes involved in citrulline-arginine metabolism, argininosuccinate synthetase (ASS), argininosuccinate lyase (ASL), and NOS were expressed in rat islets and insulinoma HIT T15 cells [5].

Psychiatry related information on Ass

• From the three common alleles (epsilon2, epsilon3 and epsilon4), epsilon4 has been suggested to promote amyloid beta (Ass) plaque fibrillation, one hallmark of Alzheimer's disease [6].

High impact information on Ass

• Coinduction of nitric oxide synthase, argininosuccinate synthetase, and argininosuccinate lyase in lipopolysaccharide-treated rats. RNA blot, immunoblot, and immunohistochemical analyses [7].
• Nitric oxide (NO) is synthesized from arginine by nitric oxide synthase (NOS), and citrulline which is generated can be recycled to arginine by argininosuccinate synthetase (AS) and argininosuccinate lyase (AL) [7].
• In addition, dexamethasone also inhibited cytokine induction in CMEC of argininosuccinate synthase, the rate-limiting enzyme for the de novo synthesis of arginine from citrulline [8].
• Argininosuccinate synthetase mRNA and activity are induced by immunostimulants in vascular smooth muscle. Role in the regeneration or arginine for nitric oxide synthesis [9].
• Channeling of citrulline from its site of synthesis by ornithine transcarbamylase in the mitochondrial matrix to argininosuccinate synthetase in the cytoplasmic space was also shown [10].

Chemical compound and disease context of Ass

• Citrullinemia is an inborn error of the urea cycle caused by deficient argininosuccinate synthetase, which leads to accumulation of L-citrulline and ammonia in tissues and body fluids [11].
• Rat argininosuccinate synthetase was expressed in Escherichia coli as a fusion protein with maltose binding protein, cleaved from binding protein, and purified [12].

Biological context of Ass

• Nucleotide sequence of the cDNA encoding the rat argininosuccinate synthetase [13].
• To test the hypothesis that the upregulation and/or persistence of amyloidogenic proteins is exacerbated in aged rats after cerebral ischemic stroke, we studied the expression of ssAPP and its proteolytic product Ass in the brains of young and old rats 7 days after temporary cerebral ischemia [1].
• (ii) These cell lines thus constitute valid experimental models for use in further detailed studies on the molecular mechanism(s) through which glucocorticoids and intermediary metabolites effect a selective modulation of arginase and argininosuccinate-synthetase gene expression in the differentiated mammalian liver [2].
• Addition of dexamethasone induced the development of carbamoyl-phosphate synthetase, argininosuccinate synthetase, argininosuccinase and arginase activities as soon as day 16.5 of gestation [14].
• These findings suggest that the circadian rhythm of argininosuccinate synthetase in the liver might be directly responsible for the rhythms of change in urea concentrations in the liver, blood and urine [15].

Anatomical context of Ass

• We have examined and characterized the regulation by glucocorticoids of the levels of arginase and argininosuccinate synthetase in two rat hepatoma cell lines (H4-II-E-C3 and MH1C1) [2].
• Induction of argininosuccinate synthetase in rat brain glial cells after striatal microinjection of immunostimulants [16].
• Foetal-rat hepatocytes were cultured in primary monolayer culture, and activity changes of argininosuccinate synthetase (ASS, EC 6.3.4.5) and argininosuccinase (ASL, EC 4.3.2.1) were followed under defined hormone conditions [17].
• Argininosuccinate synthetase: localization in astrocytes and role in the production of glial nitric oxide [18].
• 3. Argininosuccinate synthetase (EC 6.3.4.5) activity in rat liver cytosol is inhibited by alanine in a competitive manner with respect to citrulline [19].

Associations of Ass with chemical compounds

• The pattern of metabolite changes indicates that although both effectors stimulated glutaminase and increased supply of aspartate to the argininosuccinate synthetase, dibutyryl cAMP gave greater activation of glutaminase whereas the adrenergic agonists gave greater stimulation of later steps on the biosynthetic pathways [20].
• The induction of carbamyl phosphate synthetase and argininosuccinate synthetase mRNA during the fetal and postnatal development of the rat was studied by dot blot analysis of isolated mRNA [21].
• The activity changes of two urea cycle enzymes, argininosuccinate synthetase (ASS) and argininosuccinase (ASL), were followed after corticosteroid and pancreatic hormone treatments in utero and in primary cultured fetal hepatocytes [22].
• In lactating rats the activities of carbamoyl-phosphate synthase, ornithine carbamoyltransferase and argininosuccinate synthase were lower than in control virgin rats [23].
• Allyl alcohol suppressed the expression of urea cycle enzymes, whereas that of the rate limiting enzymes carbamoylphosphate synthase and argininosuccinate synthetase was increased by the non-lethal but not by the sub-lethal dose of acetaminophen [24].

Regulatory relationships of Ass

• Insulin (1.8 X 10(-6)M) alone had no effect on the enzyme activities, but when incubated together with dexamethasone, it abolished the dexamethasone-induced increase of argininosuccinate synthetase and inhibited the argininosuccinate lyase activity by 80%, at 24 h [25].

Other interactions of Ass

• This includes genes coding for proteins involved in glutamine utilization, such as argininosuccinate synthetase (ureagenesis) or phosphoenolpyruvate carboxykinase (gluconeogenesis) [26].
• The development of argininosuccinate synthetase activity which is completely blocked by the suppression of glucocorticoids in the fetal liver is affected by neither glucagon nor thyroxine [27].
• The enzymes were alanine aminotransferase (EC 2.6.1.2) and argininosuccinate synthase (EC 6.3.4.5) [28].
• Argininosuccinate synthetase-like immunoreactive glomeruli were distributed in the caudomedial part of the accessory olfactory bulb, and most of them were also strongly NADPH-d positive [29].
• The diurnal rise of argininosuccinate synthetase an glutamate dehydrogenase is also totally inhibited by cycloheximide, whereas cordycepin, alpha-amanitin, and 5-azacytidine are ineffective in the first phase of enzyme accumulation [30].

Analytical, diagnostic and therapeutic context of Ass

• In addition, the expression of carbamoylphosphate synthetase and argininosuccinate synthetase protein was studied by immunohistochemistry [31].
• Crystallization and some properties of argininosuccinate synthase from rat liver [32].
• On the other hand, argininosuccinate synthetase mRNA (by RT-PCR) and protein (by Western blot) was marginally detectable in control AMphi, but clearly induced after exposure to LPS [33].
• In fetal rat liver explants maintained in organ culture, the addition of dexamethasone (4.6 X 10(-6)M) produced a 2- to 3-fold increase in the activity of argininosuccinate synthetase and in argininosuccinate lyase after 24 and 48 h of incubation [25].

References