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The Rous Sarcoma Virus Oncogene and its Proto-Oncogene Counterpart
Published in Pimentel Enrique, Oncogenes, 2020
The ribosomal protein S6 is also phosphorylated by the action of pp60v-src.118 The phosphorylation occurs not in tyrosine but in serine residues and a similar modification is induced by a variety of tumor viruses as well as by serum or phorbol ester.119,120 Microinjection of pp60v-src into Xenopus oocytes increases phosphorylation of protein S6 and accelerates the rate of progesterone-induced meiotic maturation.121 pp60v-src Also phosphorylates three glycolytic enzymes (enolase, phosphoglycerate mutase, and lactate dehydrogenase) in cultured cells.122 These enzymes catalyze three out of the last four steps of glycolysis and their modification may contribute to the high rate of aerobic glycolysis observed in transformed cells, evident from the rapid glucose uptake and lactate production observed in cells transformed by different agents, including RSV.
Anaerobic endurance: the speed endurance sports
Published in Nick Draper, Helen Marshall, Exercise Physiology, 2014
It is at step seven that the first synthesis of ATP occurs within the glycolytic pathway. Phosphoglycerate kinase catalyses the phosphorylation of ADP through the energy released by the removal of the phosphate group from carbon 1 from each 1, 3-bisphosphoglycerate molecule. This results in the creation of an ATP from each of the trioses. The energy balance for glycolysis after step seven is, therefore, a net ATP gain of 0 (two ATP consumed during steps one and three; two ATP produced at step 7). In step eight of glycolysis the remaining phosphate in 3-phosphoglycerate (the product of step seven) is transferred, in a reaction catalysed by phosphoglycerate mutase, from carbon 3 to carbon 2. The product of this reaction is named, not surprisingly, 2-phosphoglycerate.
Role of Fructose 2,6-Bisphosphate in the Control of Glycolysis in Liver, Muscle, and Adipose Tissue
Published in Rivka Beitner, Regulation of Carbohydrate Metabolism, 1985
The comparison of fructose-2,6-bisphosphate with 2,3-bisphosphoglycerate can be extended to the reactions responsible for their synthesis and degradation. The synthesis and degradation of 2,3-bisphosphoglycerate can be achieved by a multifunctional enzyme which displays phosphoglycerate mutase, bisphosphoglycerate synthase, and phosphatase activities.107 The three enzymatic activities appear to be catalyzed at a common active site involving a histidyl residue which is phosphorylated by 2,3-bisphosphoglycerate or 1,3-bisphosphoglycerate. The phosphoryl-enzyme can (1) exchange the phosphoryl group with glycerate 3-phosphate or glycerate 2-phosphate regenerating the phosphoryl enzyme; (2) transfer the phosphoryl group to glycerate 3-phosphate, liberating the free enzyme and 2,3-bisphos-phoglycerate; and (3) transfer the phosphoryl group to water. These steps can be summarized as follows:
A variant in the RP1L1 gene in a family with occult macular dystrophy in a predicted intrinsically disordered region
Published in Ophthalmic Genetics, 2020
Miki Hiraoka, Aki Ishikawa, Fumiko Matsuzawa, Sei-Ichi Aikawa, Akihiro Sakurai
It has been reported that IDRs in MAPs, for example, tau proteins MAP1, MAP2, and MAP4 are involved in multiple molecular interactions and important for normal physiology; as such, variants in IDRs of these MAPs are linked to diseases (30–33). In the other report, Leu S, et al. showed the alternation at IDR region in phosphoglycerate mutase 1 (PGAM1) molecule led to conformational change and influenced the cofactor binding at the catalytic site (34). The disordered regions fold when associated with their binding partners. Their flexibility allows molecules to approach their binding partner (35). The expression of RP1L1 was found in retinal rod and cone photoreceptors at the macula section of Cynomolgus monkeys (7). And it is known that the RP1L1 deficient mice developed retinal degeneration (36). The role of RP1L1 in retinal development and maintenance is not clear yet. Since the RP1L1 genetic change was found in some cases of retinitis pigmentosa (8), it is likely that RP1L1 has similar or common pathway as RP1 in retinal development. Further investigation may disclose the binding partner of RP1L1. The IDR, including the hot spot in RP1L1, might be essential in molecular interactions for the maintenance of photoreceptor cells. These findings suggest that the genetic change in IDRs can lead to dysfunction in the retina.
Interaction of low frequency external electric fields and pancreatic β-cell: a mathematical modeling approach to identify the influence of excitation parameters
Published in International Journal of Radiation Biology, 2018
Sajjad Farashi, Pezhman Sasanpour, Hashem Rafii-Tabar
The glycolysis pathway contains a series of reactions for converting glucose into pyruvate and ATP. In the first step glucose is phosphorylated and converted to glucose-6-phosphate (G6P) which will be isomerised to the fructose-6-phosphate (F6P). The further phosphorylation of F6P by phosphofructokinase-1 enzyme produces fructose 1,6-bisphosphate, which in the next step will be cleaved into glyceraldehyde-3-phosphate (G3P) and dihydroxy acetone phosphate (DHAP) using aldolase enzyme. The DHAP is converted to further G3P by triose-phosphate isomerase. This phase, the procedure is preparatory phase and requires energy consumption. In the next step G3P oxidized to 1,3-bisphosphoglycerate incorporating glyceraldehyde 3-phosphate dehydrogenase. A large amount of energy during the oxidation of an aldehyde group will be released. In this step Nicotinamide adenine dinucleotide (NAD+) will be reduced to NADH, the reduced form of NAD+. The enzyme phosphoglycerate kinase transfers the phosphoryl group of 1,3-bisphosphoglycerate to ADP and producing ATP and 3-phosphoglycerate which the latter will be isomerized to 2-phosphoglycerate using Phosphoglycerate mutase. Using the enzyme enolase, 2-phosphoglycerate will be converted to phosphoenolpyruvate (PEP). Finally, PEP will be converted to pyruvate by pyruvate kinase. In this step one extra ATP molecule will be produced. The glycolysis pathway is depicted in Figure 1.
Research on the hepatotoxicity mechanism of citrate-modified silver nanoparticles based on metabolomics and proteomics
Published in Nanotoxicology, 2018
Jiabin Xie, Wenying Dong, Rui Liu, Yuming Wang, Yubo Li
In this study, compared with those of control group, the levels of L-serine dehydratase/L-threonine deaminase and phosphoglycerate mutase were up-regulated, while cysteine dioxygenase, alanine, isoleucine, and methionine were down-regulated. L-threonine deaminase is an enzyme in the liver that is responsible for the conversion of L-threonine to α-ketobutyric acid and ammonia. Because α-ketoester can be converted to isoleucine, L-threonine deaminase plays a key role in the synthesis of branched-chain amino acids (Du et al. 2014). Moreover, serine dehydratase and phosphoglycerate mutase 1 catalyze pyruvate and glycerol ester, respectively, to generate serine, thereby producing isoleucine. Isoleucine is a branched chain amino acid, and the carbon skeleton required for its synthesis is derived from the intermediate products of anaerobic and aerobic sugar metabolism. In this research, under the toxic effects of AgNP-cit, the level of isoleucine were potentially down-regulated by L-serine dehydratase/L-threonine deaminase and phosphoglycerate mutase, which disrupted amino acid metabolism and led to liver damage.