Adenosine triphosphate , signal transduction

Calculation of Conformational Free Energies for a Model of a Bilobal Enzyme Protein kinases catalyze the transfer of phosphate from adenosine triphosphate (ATP) to protein substrates and are regulatory elements of most known pathways of signal transduction. 

FIGURE 14-6 Main signaling pathways for histamine receptors. Histamine can couple to a variety of G-protein-linked signal transduction pathways via its four different receptors. The Hj receptor activates the phosphatidylinositol turnover via Gq/11 proteins. The other receptors either positively (H2 receptor) or negatively (H3 and H4 receptor) regulate adenylyl cyclase activity via Gs and GUo protein activation respectively. Several additional signaling pathways have been described, which are not shown. Abbreviations PfP2, phosphatidylinositol 4,5-bisphosphate PIC, phospholipase C AC, adenylyl cyclase ATP, adenosine triphosphate cAMP, cyclic AMP PKC, protein kinase C PICA, protein kinase A. 

FIGURE 1A4-1 The cell biology of extracellular acidification. When a receptor is stimulated, signal transduction pathways are Induced. Adenosine triphosphate (ATP) consumption is then compensated by the increased uptake and metabolism of glucose, which results m an increase in the excretion of acid waste products. The extracellular acidification is measured by the LAPS. (From F. Hafner. Biosens. 8/betecfron., 2000. 15. 149. With permission.)... 

In spite of their biological and agricultural importance, only in the last decade the basic molecular mechanism of their biosynthesis and signal transduction have been elucidated. The first step in the isoprenoid CK biosynthesis is the M-prenylation of adenosine-5 -phosphate (AMP, ADP, or ATP) with DMAPP or hydroxymethylbutenyl diphosphate (HMBDP) catalyzed by adenosine phosphate-isopentenyltransferase (IPT). Plant IPTs preferentially utilize ATP or ADP as the isoprenoid acceptors to form isopentenyl riboside 5 -triphosphate (iPRTP) and... 

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