Copper is an essential trace element in living systems, present in the parts per million concentration range. It is a key cofactor in a diverse array of biological oxidation-reduction reactions. These involve either outer-sphere electron transfer, as in the blue copper proteins and the Cu{sub A} site of cytochrome oxidase and nitrous oxide redutase, or inner-sphere electron transfer in the binding, activation, and reduction of dioxygen, superoxide, nitrite, and nitrous oxide. Copper sites have historically been divided into three classes based on their spectroscopic features, which reflect the geometric and electronic structure of the active site: type 1 (T1) or blue copper, type 2 (T2) or normal copper, and type 3 (T3) or coupled binuclear copper centers. 428 refs.

Multicopper Oxidases and Oxygenases

https://scholarlypublications.universiteitleiden.nl/access/item%3A3138188/view

A common genetic variation in the 3'-untranslated region of the prothrombin gene is associated with elevated plasma prothrombin levels and an increase in venous thrombosis.

The molecular basis of blood coagulation

Ceruloplasmin is a serum ferroxidase that contains greater than 95% of the copper found in plasma. This protein is a member of the multicopper oxidase family, an evolutionarily conserved group of proteins that utilize copper to couple substrate oxidation with the four-electron reduction of oxygen to water. Despite the need for copper in ceruloplasmin function, this protein plays no essential role in the transport or metabolism of this metal. Aceruloplasminemia is a neurodegenerative disease resulting from inherited loss-of-function mutations in the ceruloplasmin gene. Characterization of this disorder revealed a critical physiological role for ceruloplasmin in determining the rate of iron efflux from cells with mobilizable iron stores and has provided new insights into human iron metabolism and nutrition.

Ceruloplasmin metabolism and function.

https://archive-ouverte.unige.ch/unige:36461/ATTACHMENT01

Interleukin-1-inducible genes in endothelial cells. Cloning of a new gene related to C-reactive protein and serum amyloid P component.

A cDNA for human ceruloplasmin (EC 1.16.3.1) was identified in a human liver cDNA library by screening with two mixtures of synthetic oligodeoxyribonucleotides that were complementary to two regions of ceruloplasmin mRNA as predicted from the amino acid sequence of plasma ceruloplasmin. The resulting clone (phCP1) contained DNA coding for amino acid residues 202-1046 of the protein, followed by a stop codon, a 3' untranslated region of 123 base pairs, and a poly(A) tail. To isolate cDNAs encoding the 5' end of ceruloplasmin mRNA, a cDNA library was constructed in lambda gt10. The cDNA for this library was synthesized by reverse transcription of human liver poly(A)+ RNA, using random oligonucleotides as primers. When this cDNA library was screened by using a 5' fragment of phCP1 as a hybridization probe, several positive clones were identified. One of these clones (lambda hCP1) contained DNA coding for a probable signal peptide of 19 amino acid residues followed by DNA coding for residues 1-380 of plasma ceruloplasmin. Blot hybridization analysis showed that ceruloplasmin mRNA from human liver and the human hepatoma cell line HepG2 is 3700 nucleotides in size. Liver contained an additional mRNA species that is like ceruloplasmin mRNA and is 4500 nucleotides in size. Comparison of the complete nucleotide sequences of human ceruloplasmin cDNA and human clotting factor VIII cDNA showed regions of sequence homology, suggesting that these two proteins have evolved from a common ancestor.

https://www.pnas.org/content/pnas/83/14/5086.full.pdf

Complete cDNA sequence of human preceruloplasmin

The gene for human prothrombin, or factor II (F2) has been assigned to 11p11-q12 by the combined use of a panel of somatic cell hybrid DNAs and in situ hybridization, using both cDNA and genomic probes. In addition, the cDNA probe for F2 recognizes a homologous sequence which has been tentatively mapped to the X chromosome. Similar approaches have been used to confirm the assignment of the ceruloplasmin gene, but to regionally localize it more proximally than previously reported (3q21-q24). These results provide further evidence that genes encoding the coagulation factors and related proteins are dispersed throughout the human genome.

Human genes encoding prothrombin and ceruloplasmin map to 11p11-q12 and 3q21-24, respectively.

A processed pseudogene for human ceruloplasmin has been isolated that contains DNA corresponding to the functional gene sequence encoding the carboxy-terminal 563 amino acid residues and the 3' untranslated region. The pseudogene appears to have arisen from a processed RNA species, since intervening sequences coincident with those of the functional gene have been removed, with the exception of a short segment of intronic sequence which denotes the 5' boundary of the pseudogene. The nucleotide sequence of the pseudogene is highly homologous (97% sequence identity) with that of the wild-type gene, suggesting that pseudogene formation was a relatively recent evolutionary event. In addition to single base substitutions, there is a large 213 base pair (bp) deletion in the pseudogene sequence which corresponds to the location of an intron-exon junction in the functional gene. A 4 bp duplication that occurs at amino acid residue 683 of the wild-type coding sequence results in a frameshift mutation and introduces a premature translational termination codon at this point. This is concordant with the inability to detect a human liver transcript corresponding to the pseudogene by nuclease S1 mapping analysis. The 3' end of the pseudogene is characterized by a 62 bp segment composed mainly ofmore » repeated TC dinucleotides. On the basis of genomic Southern blot analysis performed under high-stringency conditions, the pseudogene that the authors have identified seems to comprise the only sequence in the human genome that is closely related to the wild-type gene. Using somatic cell hybridization, they have mapped the pseudogene to human chromosome 8. This differs from the site of the wild-type ceruloplasmin locus, which has been assigned to chromosome 3.« less

Isolation and characterization of a processed gene for human ceruloplasmin

During the past 25 years, studies in many different laboratories throughout the world have led to our present understanding of the mechanisms of blood clotting. This process involves the complex interaction of platelets, endothelial cells lining the blood vessels, and a group of plasma proteins called the clotting factors. Of these three components, the actions of the clotting factors are perhaps best understood. Through a stepwise series of reactions, these proteins are activated ultimately leading to the formation of a tough, insoluble fibrin clot (reviewed in 1 and 2).

Marlys L. Koschinsky

Papers

Complete cDNA sequence of human preceruloplasmin

Human genes encoding prothrombin and ceruloplasmin map to 11p11-q12 and 3q21-24, respectively.

Isolation and characterization of a processed gene for human ceruloplasmin

Structure of the genes encoding proteins involved in blood clotting