Glucosidases regulation

Geerlings A, Martinez-Lozano Ibanez M, Memelink J, van der Heijden R, Verpoorte R (2000) The strictosidine 6-D-glucosidase gene from Catharanthus roseus is regulated coordinately with other terpenoid-indole alkaloid biosynthetic genes and the encoded enzyme is located in the endoplasmic reticulum. J Biol Chem 275 3051-3056... 

Fig. 3. Biosynthesis of TIAs in C. roseus. Solid arrows indicate single enzymatic conversions, whereas dashed arrows indicate multiple enzymatic conversions. AS Anthranilate synthase, DXS D-l-deoxyxylulose 5-phosphate synthase G10H geraniol 10-hydroxylase CPR cytochrome P450 reductase TDC tryptophan decarboxylase STR strictosidine synthase SGD strictosidine /1-D-glucosidase D4H desacetoxyvindoline 4-hydroxylase DAT acetyl-CoA 4-O-deacetylvindoline 4-O-acetyl transferase. Genes regulated by ORCA3 are underlined. Reprinted with permission from [91]. Copyright (2000) American Association for the Advancement of Science...

The versatility of strictosidine as a central intermediate for the biosynthesis of a variety of alkaloids is based on the highly reactive dialdehyde produced by the action of strictosidine p-D-glucosidase. This reactive intermediate is converted by uncharacterized enzymes into the major corynanthe, iboga, and aspidosperma skeletons that are elaborated into die several hundred alkaloids found in Catharanthns roseus. Since the biosynthesis of strictosidine appears to occur within plant vacuoles, there has been much speculation, but little is known, about the factors that regulate the accumulation of strictosidine within the vacuole, or which trigger its mobilization for further elaboration. It is well known that glycosides of different natural product classes are located within plant vacuoles. 

The intestinal oligo- and disaccharidases are fixed components of the cell membrane of the brush border region of the wall of the small intestine. These enzymes digest dietary carbohydrate to monosaccharides which are absorbed through the intestinal wall. They include sucrase, maltase, isomaltase, lactase, trehalase, and hetero-p-glucosidase. In the late 1970s, it was realized that inhibition of all or some of these activities could regulate the absorption of carbohydrate, and that these inhibitors could... 

Ida H, Eto Y, Ogawa S, Matsuzaki Y, Sawa M, Inoue T, Hi-gaki K, Nanba E, Ohno K, Suzuki Y. N-octyl-beta-valienamine up-regulates activity of F213I mutant beta-glucosidase in cultured... 

MAL2 regulator of a-D-glucosidase synthesis some mutants are constitutive, others are non-utilizers 348-350... 

Maltose MALA MALS regulator of a-D-glucosidase synthesis constitutive for a-D-glucosidase synthesis and resistant to catabolite repression non-utilizing mutants have been found 348-351 349,352... 

MAL6 regulator of a-D-glucosidase and maltose carrier recessive mutants found (t) maltose non-utilizers, (ii) constitutive utilizers 349,353-355... 

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