tumor-associated hydroquinone oxidase; tNOX; cytosolic ovarian carcinoma antigen 1; APK1 antigen [Includes: Hydroquinone [NADH] oxidase; Protein disulfide-thiol oxidoreductase] (COVA1, ENOX2)

Function: 1) role in cell growth 2) terminal oxidase of plasma electron transport from cytosolic NADPH via hydroquinones to acceptors at the cell surface 3) hydroquinone oxidase activity alternates with a protein disulfide-thiol oxidoreductase activity 4) facilitates physical membrane displacements associated with vesicle budding or cell enlargement 5) activities oscillate with a period of 22 minutes & play a role in control of the ultradian cellular biological clock 6) inhibited by antitumor sulfonylurea LY181984, vabilloid capsaicin, & retinoids Cofactor: Cu+2 Structure: 1) glycosylated 2) contains 1 RRM domain (RNA recognition motif) Compartment: extracellular (cancer) & plasma membrane-associated Alternative splicing: named isoforms=2 Pathology: - found in the sera of cancer patients (wide variety) - breast cancer, prostate cancer, lung cancer, ovarian cancer, leukemias, & lymphomas - not found in serum of healthy volunteers or patients with disorders other than cancer - shed into serum by cancer cells (putative) - expressed on the cell borders of renal carcinoma & ovarian carcinoma, but not on the borders of surrounding non-cancerous stromal cells - several properties associated with prions including - resistance to proteases - resistance to cyanogen bromide digestion - ability to form amyloid filaments resembling those of spongiform encephalopathies

Properties

SIZE: MW = 70 kD entity length = 610 aa MOTIF: proline-rich region SITE: 58-125 MOTIF: proline residue (SEVERAL) RNP motif NAME: RNP motif SITE: 128-207 FOR-BINDING-OF: ribonucleic acid MOTIF: ribonucleoprotein-1 motif NAME: ribonucleoprotein-1 motif FOR-BINDING-OF: ribonucleic acid MOTIF: ribonucleoprotein-1 motif ribonucleoprotein-2 motif ribonucleoprotein-2 motif FOR-BINDING-OF: ribonucleic acid MOTIF: ribonucleoprotein-1 motif ribonucleoprotein-2 motif coiled coil {293-328} coiled coil {381-505}

Database Correlations

OMIM 300282 UniProt Q16206 Pfam PF00076

References

UniProt :accession Q16206