Regulated degradation of 3-hydroxy-3-methylglutaryl-coenzyme A reductase in permeabilized cells.
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چکیده
منابع مشابه
ATP-dependent degradation of 3-hydroxy-3-methylglutaryl coenzyme A reductase in permeabilized cells.
A system for the assay of 3-hydroxy-3-methyglutaryl (HMG) coenzyme A (CoA) reductase in digitonin-permeabilized Chinese hamster ovary cells is described. Under these conditions, HMG-CoA reductase remained intact and associated with the endoplasmic reticulum, and values for Km (HMG-CoA), Ki (mevinolin), and active/total activity were similar to those seen in sonicated cell preparations. However,...
متن کاملSterol-induced dislocation of 3-hydroxy-3-methylglutaryl coenzyme A reductase from membranes of permeabilized cells
The polytopic endoplasmic reticulum (ER)-localized enzyme 3-hydroxy-3-methylglutaryl CoA reductase catalyzes a rate-limiting step in the synthesis of cholesterol and nonsterol isoprenoids. Excess sterols cause the reductase to bind to ER membrane proteins called Insig-1 and Insig-2, which are carriers for the ubiquitin ligases gp78 and Trc8. The resulting gp78/Trc8-mediated ubiquitination of re...
متن کاملPurification of 3-hydroxy-3-methylglutaryl coenzyme A reductase.
The enzyme 3-hydroxy-3-methylglutaryl coenzyme agarose, glucose-6-phosphate dehydrogenase, and aldolA reductase from human liver was purified to homogeneity. ase were from Sigma Chemical co.; agarose-hexaneHMG-CoA was from P-L Biochemicals; bovine serum Electrophoresis of the purified human enzyme on non-denaturing gels revealed a single protein-staining band that co-migrated with reductase act...
متن کاملThe regulated degradation of a 3-hydroxy-3-methylglutaryl-coenzyme A reductase reporter construct occurs in the endoplasmic reticulum.
The rate-limiting enzyme in cholesterol biosynthesis, 3-hydroxy-3-methylglutaryl-coenzyme A (HMG CoA) reductase, is regulated at a number of levels. One important mechanism is regulation of the half-life of the protein by a controlled proteolytic system. This comes about in response to downstream products of the sterol biosynthetic pathway. Little is known about this system, including where in ...
متن کاملThe ubiquitin-proteasome pathway mediates the regulated degradation of mammalian 3-hydroxy-3-methylglutaryl-coenzyme A reductase.
3-Hydroxy-3-methylglutaryl-coenzyme A reductase (HMGR), the key regulatory enzyme in the mevalonate (MVA) pathway, is rapidly degraded in mammalian cells supplemented with sterols or MVA. This accelerated turnover was blocked by N-acetyl-leucyl-leucyl-norleucinal (ALLN), MG-132, and lactacystin, and to a lesser extent by N-acetyl-leucyl-leucyl-methional (ALLM), indicating the involvement of the...
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ژورنال
عنوان ژورنال: Journal of Biological Chemistry
سال: 1992
ISSN: 0021-9258
DOI: 10.1016/s0021-9258(18)42246-6