In vivo expression of copper-transporting proteins in rat brain regions

• Published in: Biology bulletin of the Russian Academy of Sciences Vol. 32; no. 2; pp. 108 - 120
• Main Authors: Platonova, N. A., Barabanova, S. V., Povalikhin, R. G., Tsymbalenko, N. V., Danilovskii, M. A., Voronina, O. V., Dorokhova, I. I., Puchkova, L. V.
• Format: Journal Article
• Language: English
• Published: 01.03.2005
• ISSN: 1062-3590; 1608-3059
• DOI: 10.1007/s10525-005-0016-3

Expression of two copper-transporting P1-type ATPases (ATP7A and ATP7B), the CTR1 protein, a high-affinity copper transporter, and ceruloplasmin (Cp), a copper-containing ferroxidase was studied. The level of mRNA of these proteins was determined by RT-PCR analysis, the distribution of polypeptides encoded by these genes was determined by immunoblotting, and the type of cells expressing these genes was identified immunohistochemically. It was found that the major product of Cp gene in the brain is the cell membranebound Cp. Secretory Cp, whose molecule contains the greatest number of weakly associated copper atoms, is synthesized in the choroid plexus. CTR1 mRNA is evenly distributed in the brain; however, its content is twice higher in the vascular plexus. The Atp7a gene is active in all brain regions, whereas the Atp7b gene is active only in the hypothalamus. The membrane-bound Cp is expressed in glial cells of all types and in ependyma cells. ATP7B and ATP7A are expressed predominantly in ependymyocytes and neurons, respectively. The organization of copper transport in mammalian brain is discussed.