The revelation of expressing region in the processed ceruloplasmin gene in human genome by biocomputational and biochemical methods

Translation in all open reading frames (ORF) of human ceruloplasmin (Cp) pseudogene revealed the only translating sequence of 984 nucleotides. The amino acid sequence contains a signal peptide for mitochondrial protein import at N-terminus. The predicted protein without taking the signal peptide into consideration has 92% identity to the corresponding Cp fragment. It contains 20 amino acid substitutions, 8 of them are significant. There is His-X-His motif in the center of a molecule that is typical for copper containing oxidases. Potential copper-binding site appears as a result of the substitution P923H along human Cp sequence. Cp pseudogene transcription product was found in the cultured human cell lines HepG2 and HuTu 80 using RT-PCR strategy. Cp polypeptides with molecular weight of nearly 30 kDa were found in mitochondria of HuTu 80 cells. The possible biological role of mitochondrial Cp is under discussion.