Ceruloplasmin (CER) Protein

The protein encoded by this gene is a metalloprotein that binds most of the copper in plasma and is involved in the peroxidation of Fe(II)transferrin to Fe(III) transferrin. Mutations in this gene cause aceruloplasminemia, which results in iron accumulation and tissue damage, and is associated with diabetes and neurologic abnormalities. Two transcript variants, one protein-coding and the other not protein-coding, have been found for this gene. [provided by RefSeq, Feb 2012]

CP: Ceruloplasmin is a blue, copper-binding (6-7 atoms per molecule) glycoprotein. It has ferroxidase activity oxidizing Fe(2+) to Fe(3+) without releasing radical oxygen species. It is involved in iron transport across the cell membrane. Provides Cu(2+) ions for the ascorbate-mediated deaminase degradation of the heparan sulfate chains of GPC1. May also play a role in fetal lung development or pulmonary antioxidant defense. Defects in CP are the cause of aceruloplasminemia (ACERULOP). It is an autosomal recessive disorder of iron metabolism characterized by iron accumulation in the brain as well as visceral organs. Clinical features consist of the triad of retinal degeneration, diabetes mellitus and neurological disturbances. Ceruloplasmin levels are decreased in Wilson disease, in which copper cannot be incorporated into ceruloplasmin in liver because of defects in the copper-transporting ATPase 2. Belongs to the multicopper oxidase family.

Protein type: Secreted, signal peptide; Oxidoreductase; EC 1.16.3.1; Cofactor and Vitamin Metabolism - porphyrin and chlorophyll; Secreted

Chromosomal Location of Human Ortholog: 3q23-q25

Cellular Component: extracellular space; lysosomal membrane; extracellular region

Molecular Function: ferroxidase activity; copper ion binding; chaperone binding

Biological Process: cellular iron ion homeostasis; copper ion transport; transmembrane transport

Disease: Aceruloplasminemia