Biosynthesis and signal transduction

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... 

GTP Guanosine triphosphate, a nucleotide serving as a switch in many important processes including protein biosynthesis and signal transduction. 

It has long been known that insulin ( and other hormones and growth factors) can stimulate protein biosynthesis. The signal transduction pathway linking insulin to the translation apparatus was, imtil recently, imclear. However, insight is now being gained into this mechanism (Pause et al, 1994, review Proud and Denton, 1997). 

CONTROL MECHANISMS OF ALKALOID BIOSYNTHESIS Gene Expression and Signal Transduction... 

Structure-activity relationship Biosynthesis and Metabolism Biosynthesis of castasterone Biosynthesis of brassinolide from castasterone Regulation of biosynthesis Metabolism and its regulation Physiology and Signal Transduction Physiology Signal transduction Jasmonates and Oxylipins Introduction Chemistry Chemical structure Chemical stability... 

Since the publication of the previous edition of the book Comprehensive Natural Products Chemistry in 1999,547 research on abscisic acid (ABA, 1) has progressed especially concerning its biosynthesis, catabolism, and signal transduction using molecular biology techniques. In this chapter, descriptions of these subjects have been extensively revised and the chemistry of ABA is described in brief although the essential information has been retained. 

Triazole inhibitors of BR biosynthesis such as brassinazole and Brz22012 (Figure 32) have been developed and used to analyze the physiological function and signal transduction of BRs.786... 

The number of reports suggesting that peptides in plants play an important role as hormone-like molecules has been increasing in recent years. Most of the biologically active peptides are biosynthesized from precursors by processing and/or specific modification, as was the case with PSK and CLE peptides. In order to develop peptide hormone research, it is necessary to accurately determine the chemical structures of mature peptides. Once the chemical structures of the peptides are determined, it is expected that research will further expand, focusing on biosynthesis, receptors, and signal transduction. 

See also Substrate Level Phosphorylation, Nucleotide Salvage Synthesis, De Novo Biosynthesis of Purine Nucleotides, Nucleotides, Guanine, G Proteins and Signal Transduction... 

PBAN binding to a receptor results in signal transduction events to stimulate the pheromone biosynthetic pathway (Fig. 5). Receptor activation results in the influx of extracellular calcium and has been demonstrated in a number of moths [163-168]. The increase in cytosolic calcium can directly stimulate pheromone biosynthesis in some moths [165-168] or it will stimulate the production of cAMP [169,170]. So far cAMP has only been implicated in signal... 

The oligosaccharide components play a direct and central role in the biosynthesis, secretion, serum half-life and potency of the gonadotrophins. The sugar components attached to the a-subu-nits play an important role in dimer assembly and stability, as well as hormone secretion and possibly signal transduction. The sugars associated with the P-subunit, while contributing to dimer assembly and secretion, appear to play a more prominent role in clearance of the hormone from circulation. 

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