A yeast (Saccharomyces cerevisiae) deletion library was screened based on NADH fluorescence using a 384 well plate assay and robotics to identify a yeast isolate lacking the 24 min periodic cell surface oxidase. The oxidase was shown previously to be a candidate ultradian oscillator of the yeast’s biological clock. The cDNA was cloned from a yeast overexpression library and the encoded protein was expressed in bacteria and characterized. Glyceraldehyde-3-phosphate dehydrogenase activity was used as the cellular circadian indicator. The identified gene was YML117W which encodes a ca 126 kDa putative RNA-binding protein. The candidate ENOX1 activity from yeast had functional characteristics similar to those of other constitutive ENOX1 proteins of eukaryotes exhibiting oscillating activities with a temperature independent period length of 24 min phased by melatonin and low frequency electromagnetic fields and susceptible to inhibition by the ENOX1 inhibitor, simalikalactone D. The YML117W deletion mutant cells lacked the ENOX1 clock output present in wild type yeast. The findings identify YML117W as the ENOX1 of Saccharomyces cerevisiae and support its proposed function as an ultradian oscillator of the yeast biological clock.
 Morré, D.J. and Morré, D.M. (2003) Cell surface NADH oxidases (ECTO-NOX proteins) with roles in cancer, cellular time-keeping, growth, aging and neurodegenerative disease. Free Radical Research, 37, 9795-9808. doi:10.1080/1071576031000083107
 Morré, D.J. (1995) NADH oxidase activity of HeLa plasma membranes inhibited by the anticancer sulfonylurea N-(4-methylphenylsulfonyl)-N-(4chloro-phenyl) urea (LY181984) at an external site. Biochimica et Biophysica Acta, 1240, 201-208. doi:10.1016/0005-2736(95)00199-9
 Jiang, Z., Gorenstein, N.M., Morré, D.M. and Morré, D.J. (2008) Molecular cloning and characterization of a candidate human growth-related and time-keeping constitutive cell surface hydroquinone (NADH) oxidase. Biochemistry, 47, 14028-14038. doi:10.1021/bi801073p
 Chueh, P.J., Kim, C., Cho, N., Morré, D.M. and Morré, D.J. (2002) Molecular cloning and characterization of a tumor-associated, growth-related and time-keeping hydroquinone (NADH) oxidase (NOX) of the HeLa cell surface. Biochemistry, 41, 3732-3741. doi:10.1021/bi012041t
 Morré, D.J., Guo, F. and Morré, D.M. (2003) An agingrelated cell surface NADH oxidase (arNOX) generates superoxide and is inhibited by coenzyme Q. Molecular and Cellular Biochemistry, 254, 101-109. doi:10.1023/A:1027301405614
 Tang, X., Chueh, P.J., Jiang, Z., Layman, S., Martin, B, Kim, C., et al. (2010) Essential role of copper in the activity and regular periodicity of a recombinant, tumorassociated, cell surface, growth-related and time-keeping hydroquinone (NADH) oxidase with protein disulfidethiol interchange activity (ENOX2). Journal of Bioenergetics and Biomembrances, 42, 355-360.
 Tang, X., Parisi, D., Spicer, B., Morré, D.M. and Morré, D.J. (in Press) Molecular cloning and characterization of human age-related NADH oxidase (arNOX) proteins as members of the TM9 superfamily of transmembrane proteins. Advances in Biological Chemistry.
 Dick, S.S., Ryuzoji, A., Morré, D.M. and Morré, D.J. (2013) Ultradian oscillators of the circadian clock in Saccharomyces cerevisiae. Advances in Biological Chemistry, 3, 59-69. doi:10.4236/abc.2013.31008
 Brightman, A.O., Wang, J., Miu, R.K., Sun, I.L., Barr, R., Crane, F.L., et al. (1992) A growth factorand hormone-stimulated NADH oxidase from rat liver plasma membrane. Biochimica et Biophysica Acta, 1105, 109117. doi:10.1016/0005-2736(92)90168-L
 Kishi, T., Morré, D.M. and Morré, D.J. (1999) The plasma membrane NADH oxidase of HeLa cells has hydroquinone oxidase activity. Biochimica et Biophysica Acta, 1412, 66-77. doi:10.1016/S0005-2728(99)00049-3
 Morré. D.J., Gomez-Rey, M.L., Schramke, C., Em, O., Lawler, J., Hobeck, J. and Morré, D.M. (1999) Use of dipyridyl-dithio substrates to measure directly the protein disulfide-thiol interchange activity of the auxin stimulated NADH: Protein disulfide reductase (NADH oxidase) of soybean plasma membranes. Molecular Cellular Biochemistry, 200, 7-13. doi:10.1023/A:1006916116297
 Foster, K., Anward, N., Pogue, R., Morré, D.M., Keenan, T.W. and Morré, D.J. (2003) Decomposition analyses applied to a complex ultradian biorhythm: The oscillating NADH oxidase activity of plasma membranes having a potential time-keeping (clock) function. Nonlinearity in Biology, Toxicology and Medicine, 1, 51-70. doi:10.1080/15401420390844465
 Shinohara, M.L., Loros, J.J. and Dunlap, J.C. (1998) Glyceraldhyde-3-phosphate is regulated on a daily basis by the circadian clock. Journal of Biological Chemistry, 273, 446-452. doi:10.1074/jbc.273.1.446
 Morré, D.J. and Greico, P.A. (1999) Glaucarubolone and simalikalactone D, respectively, preferentially inhibit auxin-induced and constitutive components of plant cell enlargement and the plasma membrane NADH oxidase. International Journal of Plant Science, 160, 291-297. doi:10.1086/314133
 Kelker, M., Kim, C., Chueh, P.J., Guimont, R., Morré, D.M. and Morré, D.J. (2001) Cancer isoform of a tumor-associated cell surface NADH oxidase (tNOX) has properties of a prion. Biochemistry, 40, 7351-7354. doi:10.1021/bi010596i
 Murray, D.B., Klevecz, R.R. and Lloyd, D. (2003) Generation and maintenance of synchrony in Saccharomyces cerevisiae continuous culture. Experimental Cell Research, 287, 10-15. doi:10.1016/S0014-4827(03)00068-5
 Lloyd, D., Eshantha, L., Salgado, J., Turner, M.P. and Murray, D.B. (2002) Respiratory oscillations in yeast: clock-driven mitochondrial cycles of energization. FEBS Letters, 519, 41-44. doi:10.1016/S0014-5793(02)02704-7
 Satroutdinov, A.D., Kuriyama, H. and Kobayashi, H. (1992) Oscillatory metabolism of Saccharomyces cerevisiae in continuous culture. FEMS Microbiology Letters, 98, 261-268. doi:10.1111/j.1574-6968.1992.tb05525.x
 Keulers, M., Suzuki, T., Satroutinov, A.D. and Duriyama, H. (1996) Autonomous metabolic oscillation in continuous culture of Saccharomyces cerevisiae grown on ethanol. FEMS Microbiology Letters, 142, 253-258. doi:10.1111/j.1574-6968.1996.tb08439.x
 Klevecz, R.R., Bolen, J., Forrest, G. and Murray, D.B. (2004) A genome wide oscillation in transcription gates DNA replication and cell cycle. Proceedings of the National Academy of Sciences USA, 101, 1200-1205.
 Adams, A.E. and Pringle, J.R. (1984) Relationship of actin and tubulin distribution to bud growth in wild-type and morphogenetic-mutant Saccharomyces cerevisiae. Journal of Cellular Biology, 98, 934-945. doi:10.1083/jcb.98.3.934
 Morré, D.J., Kim, C. and Hicks-Berger, C. (2006) ATPdependent and drug inhibited vesicle enlargement reconstituted using synthetic lipids and recombinant proteins. BioFactors, 28, 105-117. doi:10.1002/biof.5520280205
 Hicks-Berger, C. and Morré, D.J. (2006) Inside-out but not right side-out plasma membrane vesicles from soybean enlarge when treated with ATP + 2,4-D as determined by electron microscopy and light scattering: evidence for involvement of a plasma membrane AAAATPase. BioFactors, 28, 91-104. doi:10.1002/biof.5520280204
 Chueh, P.J., Morré, D.J., Wilkinson, F.E., Gibson, J. and Morré, D.M. (1997) A 33.5 kDa heat-and protease resistant NADH oxidase inhibited by capsaicin from sera of cancer patients. Archives of Biochemistry and Biophysics, 342, 38-47. doi:10.1006/abbi.1997.9992
 del Castillo-Olivares, A., Yantiri, F., Chueh, P.J., Wang, S., Sweeting, M., Sedlak, D., et al. (1998) A drug-responsive and protease-resistant peripheral NADH oxidase complex from the surface of HeLa S cells. Archives of Biochemistry and Biophysics, 358, 125-140. doi:10.1006/abbi.1998.0823
 Sedlak, D., Morré, D.M. and Morré, D.J. (2001) A drugunresponsive and protease-resistant CNOX protein from human sera. Archives of Biochemistry and Biophysics, 386, 106-116. doi:10.1006/abbi.2000.2180
 Morré, D.J. and Morré, D.M. (2003) The plasma membrane-associated NADH oxidase (ECTO-NOX) of mouse skin responds to blue light. Journal of Photochemistry and Photobiology B, 70, 7-12. doi:10.1016/S1011-1344(03)00023-X
 Morré, D.J., Jiang, Z., Marjanovic, M., Orczyk, J. and Morré, D.M. (2008)) Response of the regulatory behavior of CopperII containing ECTO-NOX proteins and CuIICl2 in solution to electromagnetic fields. Journal of Inorganic Biochemistry, 102, 1812-1818. doi:10.1016/j.jinorgbio.2008.06.001