Occurrence and subcellular localization of glucose 6-phosphatase in bovine thyroid

In bovine thyroid tissue the glucose 6-phosphatase activity is not entirely due to the presence of an unspecific acid phenylphosphatase nor to beta-glycerophosphatase. This glucose 6-phosphatase is very probably localized within endoplasmic reticulum membranes. It is not a good marker for distribution patterns obtained after differential pelleting. However it can be used as a marker for endoplasmic reticulum membranes after centrifugation in a zonal rotor.