Association of isolated bovine kidney cortex peroxisomes with endoplasmic reticulum.
Close lateral membrane associations of peroxisomes with endoplasmic reticulum are a common feature in bovine kidney cortex epithelial cells. Isolated highly purified peroxisome preparations from this tissue showed a remarkable and persistent copurification of peroxisomal marker enzymes with small amounts (5%) of the microsomal reference enzymes esterase and glucose-6-phosphatase. Contamination with mitochondrial and lysosomal markers was negligible. Ultrastructural examination of such preparations revealed a peculiar association of vesicles or short tubular segments with the peroxisomal membrane. Short electron dense crossbridges seemed to maintain their structural association. The cytochemical localization of glucose-6-phosphatase in peroxisome-associated membrane structures confirmed their derivation from endoplasmic reticulum. The metabolic significance of such structural peroxisome-endoplasmic reticulum associations is discussed.
D000818:Animals; D002417:Cattle; D002458:Cell Fractionation; D004721:Endoplasmic Reticulum / Q000201:enzymology / Q000648:ultrastructure*; D004848:Epithelium / Q000648:ultrastructure; D007425:Intracellular Membranes / Q000648:ultrastructure; D007672:Kidney Cortex / Q000201:enzymology / Q000648:ultrastructure*; D050356:Lipid Metabolism; D008830:Microbodies / Q000201:enzymology / Q000648:ultrastructure*