Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P50583 (asymmetrical)
 12,197 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

5-Acetyl-4-methyl-1-(beta-D-ribofuranosyl)-imidazole-5'-phosphate reacts with diphenylphospho chloridate forming the asymmetrical pyrophosphate ester. This in turn reacts with tri-n-butyl-ammonium phosphate yielding 5-acetyl-4-methyl-imidazole-riboside-5'-diphosphate and with tri-n-butylammonium pyrophosphate to give the nucleotide triphosphate. 5-Acetyl-4-methyl-imidazole-riboside-5'-pyrophosphate shows in the test with pyruvate kinase a reaction rate three times slower than that of ADP; but the same Km as that of ADP. The ATP analogue is only about 10% as effective as ATP itself in the test with hexokinase, 3-phosphoglycerate kinase and gloconate kinase. Adenylate kinase and NAD" kinase show no activity when ATP is replaced by the nucleotide-triphosphate-analogue. In presence of ATP the analogue strongly inhibits the reaction of adenylate kinase.
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PMID:[Synthesis and properties of 5-acetyl-4-methyl-1-(beta-d-ribofuranosyl)-imidazole-5' di-and-triphosphate]. 16 88

The dynamic properties of the glucose/glucose-6-phosphate cycle are studied under conditions where the phosphatase and kinase interconverting enzymes are spatially distributed. A semi-artificial membrane made of compacted plant cell walls bearing active phosphatase in its natural state, separates two compartments, one of these compartments containing soluble hexokinase. Depending only upon the two enzyme activity levels and the initial distribution of the substrates, numerous asymmetrical and vectorial behaviours can be observed, such as facilitated glucose 6-phosphate diffusion, active transport of either glucose or glucose 6-phosphate and sequential (alternative) transport between glucose and glucose 6-phosphate. A diffusion-partition reaction coupling can account for these oriented mass transfers. The possibility of such a coupling in this model system is clearly dictated by the global analog of the Curie principle. These results may provide new insight on (a) the still obscure role played by the cell-wall phosphatase activities, particularly their involvement in the transport of exogenous phosphomonoesters, and (b) the actual in vivo operation of substrate and protein cycles in view of the heterogeneity and anisotropy of the cellular milieu.
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PMID:Various vectorial behaviours of a spatially structured substrate cycle. 805 73

Optimal root architecture is established by multiple intrinsic (e.g. hormones) and extrinsic (e.g. gravity and touch) signals and is established, in part, by directed root growth. We show that asymmetrical exposure of cytokinin (CK) at the root tip in Arabidopsis (Arabidopsis thaliana) promotes cell elongation that is potentiated by glucose in a hexokinase-influenced, G protein-independent manner. This mode of CK signaling requires the CK receptor, ARABIDOPSIS HISTIDINE KINASE4 and, at a minimum, its cognate type B ARABIDOPSIS RESPONSE REGULATORS ARR1, ARR10, and ARR11 for full responsiveness, while type A response regulators act redundantly to attenuate this CK response. Ethylene signaling through the ethylene receptor ETHYLENE RESISTANT1 and its downstream signaling element ETHYLENE INSENSITIVE2 are required for CK-induced root cell elongation. Negative and positive feedback loops are reinforced by CK regulation of the expression of the genes encoding these elements in both the CK and ethylene signaling pathways. Auxin transport facilitated by PIN-FORMED2 as well as auxin signaling through control of the steady-state level of transcriptional repressors INDOLE-3-ACETIC ACID7 (IAA7), IAA14, and IAA17 via TRANSPORT INHIBITOR RESPONSE1/AUXIN SIGNALING F-BOX PROTEIN are involved in CK-induced root cell elongation. This action lies downstream of ethylene and CK induction. Intrinsic signaling in this response operates independently of the extrinsic signal touch, although actin filament organization, which is important in the touch response, may be important for this response, since latrunculin B can induce similar growth. This root growth response may have adaptive significance, since CK responsiveness is inversely related to root coiling and waving, two root behaviors known to be important for fitness.
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PMID:Cytokinin interplay with ethylene, auxin, and glucose signaling controls Arabidopsis seedling root directional growth. 2166 52