Synthetase glucan

Ray PM. Maize coleoptile cellular membranes bearing different types of glucan synthetase activity, in Plant Organelles (Reid E, ed.), Ellis Horwood, Chichester, UK, 1979, pp. 135-158. 

Ordin, L., M. J. Garber, and J. I. Kindinger. Effect of 2,4-dichlorophenoxyacetic acid on growth and on /1-glucan synthetases of peroxyacetyl nitrate pretreated Avena coleoptile sections. Physiol. Plant. 26 17-23, 1972. 

With respect to the first of these hypotheses, auxin enhances the rate of wall synthesis in virtually every tissue in which growth is also promoted.482,483 It seems certain that this stimulation extends to all components of the wall polysaccharide6,484 and to wall glycoprotein.485,486 Auxin has been shown to stimulate / -D-glucan synthetase activity in several plant-tissues.7,487... 

Cell-surface BI cellulase is envisaged as the form which is active against cellulose in peas in vivo, with a function that may be constructive in that it can act synergistically with plasma membrane-bound / -glucan synthetase complexes to enhance the rate of cellulose deposition (7,8,9). BS cellulase never appears to reach the wall in vivo in a form recognized by a BS antiserum (II). BS cellulase does not even bind readily to wall material in homogenates (Table III) despite its ability to bind to cellulose (3) and hydrolyze it (Table I). It is possible that BS cellulase functions intracellularly to hydrolyze a noncellulosic organelle-bound polysac-... 

Matthyssee and Phillips (20) isolated two nuclear proteins, from tobacco cells, that bound specifically to 2,4-D. Receptor proteins for auxins, kinetins, and GA have been found (21). Sub-cellular fractions from bean leaves were recently shown to bind abscisic acid (22). Preliminary experiments (22) indicated that maximum ABA binding activity coincides with the activities of membrane-bound Mg -dependent, K+-stimulated ATPase and glucan synthetase. Table I of Biswas and Roy (21) lists hormone receptor proteins reported in plant tissue. For a protein to qualify as a receptor molecule, it should have a high stereo-specific binding capacity (Kd 10 6 to 10 SM) for its particular hormone. In com coleoptiles, both IAA and NAA are equally effective in inducing cell elongations fractions of plasma membrane and endoplasmic reticular membrane contain receptor proteins with Kd values of 10 M to 10 M for auxins (5, 18). When one considers procedural... 

Fig. 5.—Stimulation of UDP-gIucose glucan Synthetase Activities by Conditions that Lead to Induction of a Transmembrane, Electrical Potential.169 The experiment was performed by using membrane vesicles prepared from developing cotton-fibers incorporation of radioactivity from UDP-D-[,4C]glucose into total /3-D-glucans was measured. Anion and cation concentrations were 50 mM valinomycin (VAL) was present at 5 u.M and UDP-glucose at 0.1 mM 1 /xCi per irmol. ...

Ozbun, 1. L., Hawker, J. S., and Preiss, J. 1971. Multiple forms of a-1,4 glucan synthetase from spinach leaves. Biochem. Biophys. Res. Comun. 43, 631-636. 

The deposits may function in plugging or sealing the wound caused by injury due to the pathogen and may restrict the loss of molecules and ions and the movement of toxic substances into the tissues. Little is known about induction of the synthesis of the callose although membrane-bound plant 1,3-3-glucan synthetases have been described (112). Callose formation is induced by various chemical and physical stimuli (113, 114, 115) and there is evidence that membrane disruption (116, 117), such as may result from microbial infection, can initiate callose deposition. Whether the stimulus is provided by a specific binding to plasma membranes of microbial metabolites, such as... 

The phenylamide fungicides affect especially hyphal growth and the formation of haustoria and spores in oomycetes [22]. Since spores contain many ribosomes to support early growth stages, RNA synthesis is fully operational only after spore germination therefore, later development stages are most sensitive [19]. As a consequence of RNA inhibition, the precursors of RNA synthesis (i.e., nucleoside triphosphates) are accumulated. They activate j8-l,3-glucan synthetases, which are involved in cell wall formation [19] with the result that metalaxyl-treated hyphae often produce thicker cell walls than untreated ones. 

Some properties of the 3-D-glucan synthetase from Saccharomyces cerevisiae have been described.UDP-D-Glucose is a competitive inhibitor and D-glucono-1,4-lactone is a non-competitive inhibitor of this enzyme. 

Forsee et al. (1974) separated the SG synthesizing activity from cottonball fibers on a sucrose density gradient. They measured at the same time the activity of two glucan synthetases which appeared to be involved in cell wall biosynthesis. All three activities copurified and maintained the same ratio of activities. It therefore appeared that SG synthesis was present in membrane vesicles having a glucan synthetase characteristic of the Golgi complex (Ray etal., 1%9). 

Recent studies carried out in our laboratory suggest that the mRNA for the manno-protein might have a longer half-life than the average mRNA for cellular proteins. On the other hand, inhibition of protein synthesis with cycloheximide does not interfere with glucan formation indicating that glucan synthetase(s) show a slow turnover. 

Q Phosphorylcholine-glyceride transferase Q Glucan synthetase II O Galactosyl transferase... 

Szaniszlo, P.J., M.S. Kang E. Cabib. 1985. Stimulation of p-l,3-glucan synthetase of various fungi by nucleoside triphosphates generalized regulatory mechanism for cell wall biosynthesis. J. Bacteriol. 161 1188-1194. 

C18-CcA elongase C20-CoA elongase ATP-depaident elongase CDP-choline-DG transferase Latent IDPase Glucane synthetase II... 

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