Alternative titles; symbols
HGNC Approved Gene Symbol: ENOX1
Cytogenetic location: 13q14.11 Genomic coordinates (GRCh38) : 13:43,213,130-43,786,972 (from NCBI)
Electron transport pathways are generally associated with mitochondrial membranes, but non-mitochondrial pathways are also biologically significant. Plasma membrane electron transport pathways are involved in functions as diverse as cellular defense, intracellular redox homeostasis, and control of cell growth and survival. Members of the ecto-NOX family, such as CNOX, or ENOX1, are involved in plasma membrane transport pathways. These enzymes exhibit both a hydroquinone (NADH) oxidase activity and a protein disulfide-thiol interchange activity in series, with each activity cycling every 22 to 26 minutes (Scarlett et al., 2005).
Using SDS-PAGE and ammonium sulfate fractionation, Sedlak et al. (2001) purified and concentrated a 12.5-kD protein fragment with a periodic protease-resistant and drug-unresponsive NADH oxidase (CNOX) activity from pooled sera from healthy volunteers. Polyclonal antisera generated to the CNOX fragment cross-reacted with 20.5- to 24-kD proteins of human sera, human lymphocytes, and plasma membranes from E. coli.
Sedlak et al. (2001) found that both NADH oxidation and dithiodipyridine cleavage activities of CNOX from healthy human sera oscillated with a period of 24 minutes, and the maxima alternated so that when NADH oxidation was at maximum, dithiodipyridine cleavage was at minimum. Both activities were resistant to inhibition by capsaicin, distinguishing CNOX from the cancer-associated NADH oxidase, TNOX (ENOX2; 300282).
Scarlett et al. (2005) attributed the NADH oxidoreductase activity of human osteosarcoma cells to a multifunctional 70-kD cell surface protein that cross-reacted with antisera against CNOX.
Wang et al. (2013) found that NRF1 (600879) increased ENOX1 promoter activity in human neuroblastoma cells and primary rat cortical neurons. They identified an NRF1 response element 52 to 41 bp upstream of the transcription start site of ENOX1.
Gross (2015) mapped the chromosome 13q14.11 based on an alignment of the ENOX1 sequence (GenBank BC024178) with the genomic sequence (GRCh38).
Gross, M. B. Personal Communication. Baltimore, Md. 9/2/2015.
Scarlett, D.-J. G., Herst, P. M., Berridge, M. V. Multiple proteins with single activities or a single protein with multiple activities: the conundrum of cell surface NADH oxidoreductases. Biochem. Biophys. Acta 1708: 108-119, 2005. [PubMed: 15882838] [Full Text: https://doi.org/10.1016/j.bbabio.2005.03.006]
Sedlak, D., Morre, D. M., Morre, D. J. A drug-unresponsive and protease-resistant CNOX protein from human sera. Arch. Biochem. Biophys. 386: 106-116, 2001. [PubMed: 11360993] [Full Text: https://doi.org/10.1006/abbi.2000.2180]
Wang, J.-L., Tong, C.-W., Chang, W.-T., Huang, A.-M. Novel genes FAM134C, C3orf10 and ENOX1 are regulated by NRF-1 and differentially regulate neurite outgrowth in neuroblastoma cells and hippocampal neurons. Gene 529: 7-15, 2013. [PubMed: 23939472] [Full Text: https://doi.org/10.1016/j.gene.2013.08.006]