EXPRESSION OF THE CERULOPLASMIN GENE IN VARIOUS RAT ORGANS

It was shown by the method of dot hybridization that mRNA of ceruloplasmin (CP) is contained not only in the liver but also in cells of the heart, kidneys, and in various parts of the brain. Polyribosomes isolated from these organs effectively synthesize CP in a heterotogous protein-free translation system. After pulse labeling of the proteins in vivo, the newly synthesized CP is detected in the membrane fraction of cells of the same organs. The CP formed in various organs is concentrated in the membranes of the Golgi complex and is detected in them by immunologic methods. In experiments on rats with a liver isolated from the general system of blood circulation, it was demonstrated that CP is secreted into the blood only by liver cells. It is concluded that in mammals CP exists in at least two forms, serum and intracellular.