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Visualization of Endoplasmic Reticulum Localized mRNAs in Mammalian Cells
Published on: December 17, 2012
A novel membrane associated carbonyl reducing enzyme is present in smooth endoplasmic reticulum of mouse liver
T Ahlers1, H P Bode, K J Netter
1Department of Pharmacology and Toxicology, Philipps-University of Marburg, Germany.
Abstract:
Evidence supporting the existence of two distinct carbonyl (metyrapone) reducing enzymes which differ in subcellular localization and immunological homology has been provided. A soluble enzyme, designated as carbonyl reductase (EC 1.1.1.184) is located in the cytosol. The distribution of the second, membrane associated, MPON-reductase shows an excellent linear correlation to NADPH-cytochrome c reductase and, on the other hand, is reciprocal to the RNA/protein ratio of submicrosomal preparations. This indicates that the membrane associated MPON-reductase is exclusively located in the smooth endoplasmic reticulum. Using antibodies against the purified membrane associated enzyme the extent of immunological crossreaction corresponds well to the specific activities of MPON-reductase in the granular fractions, thus further confirming the localization of this enzyme within this organelle. The absence of antigenic crossreaction to cytosolic MPON-reductase indicates differences also in terms of the immunological relationship between the two enzymes.
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