Denison, Michael

Department of Environmental Toxicology
4241 Meyer Hall
Phone: 530-752-3879
Fax: 530-752-3394




Molecular toxicology; biochemical and molecular mechanisms of action of halogenated aromatic hydrocarbons and related chemicals; mechanisms of induction of drug metabolizing enzymes; structure and function of receptors for hormones and xenobiotics; gene expression; bioassay systems for detection of environmental contaminants.

Education and Experience:

•  A.A. County College of Morris, Dover, NJ 1975 (Biology)

•  B.S. St. Francis College, Biddeford, ME 1977 (Marine Biology)

•  M.S. Mississippi State University, Starkville, MS 1980 (Animal Physiology)

•  Ph.D. Cornell University, Ithaca, NY 1983 (Environmental Toxicology)

•  Postdoc, Dept. of Clinical Pharmacol., Hospital for Sick Children, Toronto, Canada 1983-85

•  Postdoc, Dept. of Pharmacology, Stanford University, Stanford, CA 1985-88

•  Asst. Prof., Dept. of Biochemistry, Michigan State University, East Lansing, MI 1988-92

•  Asst/Assoc Prof., Dept. Environ. Toxicology, University of California, Davis, CA 1992-97

•  Professor, Dept. Environ. Toxicology, University of California, Davis, CA 1997-present


  • ETX 101 - Principles of Environmental Toxicology
  • ETX 214 - Mechanisms of Toxic Action
  • ETX 278 - Molecular Techniques

Campus Memberships:

  • Graduate Group in Agriculture and Environmental Chemistry
  • Graduate Group in Biochemistry, Molecular, Cellular & Developmental Biology
  •  Graduate Group in Pharmacology & Toxicology


Recent Publications:

Molecular Mechanisms of Receptor Action

  • Denison, M.S., Soshilov, A.A., He, G., DeGroot, D.E. and Zhao, B. (2011) Exactly the same but different: promiscuity and diversity in the molecular mechanisms of action of the aryl hydrocarbon (dioxin) receptor, Toxicol. Sci. 124, 1-22.
  •  Lee Y.C., Oslund, K.L., Thai, P., Velichko, S., Fujisawa, T., Duong, T., Denison, M.S., Wu, R. (2011) TCDD induced MUC5AC expression: Aryl hydrocarbon receptor-independent/EGFR-dependent MAPK signaling pathway, Amer. J. Respir. Cell Molec. Biol. 45, 270-276.
  • Korashy, H., Anwar-Mohamed, A., Soshilov, A., Denison, M.S. and El-Kadi, A. (2011) The p38 MAPK inhibitor SB203580 induces cytochrome P450 1A1 gene expression in murine and human hepatoma cell lines through ligand-dependent aryl hydrocarbon receptor activation, Chem. Res. Toxicol. Chem. Res. Toxicol. 19, 1540-1548.
  • Soshilov, A. and Denison, M.S. (2011) Ligand displaces heat shock protein 90 from overlapping binding sites within the aryl hydrocarbon receptor ligand-binding domain, J. Biol Chem. 286, 35275-35282.
  • Motto, I., Bordogna, A., Soshilov, A., Denison, M.S. and Bonati, L. (2011) A new aryl hydrocarbon receptor homology model targeted to improve docking reliability, J. Chem. Info. Modeling 51, 2868-2881.
  • Tiong, C.T., Chen, C., Zhang, S.J., Li, J., Soshilov, A., Denison, M.S., Lee Soon-U, L., Tam, V.H., Wong, S.P., Xu, E., Yong, E.-L. (2011) A novel prenylflavone restricts breast cancer cell growth through AhR-mediated destabilization of ERα protein, Carcinogenesis, 33, 1089-1097.
  • El-Gendy, M., Soshilov, A., Denison, M.S. and El-Kadi, A.O.S. (2012) Transcriptional and posttranscriptional inhibition of dioxin-mediated induction of CYP1A1 by harmine and harmol, Toxicol. Lett. 208, 51-61.
  • Wall, R.J., He, G., Denison, M.S., Congiu, C., Onnis, V., Fernandes, A., Bell, D.R., Rose, M., Rowlands, J.C. and Balboni, G. (2012) Novel 2-amino-isoflavones exhibit aryl hydrocarbon receptor agonist or antagonist activity in a species/cell-specific contact, Toxicol. 88, 881-887.
  • Fraccalvieri, D., Soshilov, A.A., Karchner, S.I., Franks, D.G., Pandini, A., Bonati, L., Hahn, M.E. and Denison, M.S. (2013) Comparative analysis of homology models of the Ah receptor ligand binding domain: Verification of structure-function predictions by site-directed mutagenesis of a non-functional AhR. Biochem. 52, 714-725.
  • Kamenickova, A., Anzenbacherova, E., Pavek, P., Soshilov, A.A., Denison, M.S., Anzenbacher, P. and Dvorak, Z. (2013) Pelargonidin activates the AhR and induces CYP1A1 in primary human hepatocytes and human cancer cell lines HepG2 and LS174T, Toxicol. Lett. 218, 253-259.
  • Odio, C., Holzman, S., Denison, M.S., Fraccalvieri, D., Bonati, L., Franks, D., Hahn, M.E. and Powell, W. (2013) Specific ligand binding domain residues confer low dioxin responsiveness to AHR1β of Xenopus laevis, Biochem., In Press. PMID: 23394719.

Receptor-Based Bioassays for Xenobiotics

  • He, G., Zhao, B. and Denison, M.S. (2011) Identification of benzothiazole derivatives and polycyclic aromatic hydrocarbons as aryl hydrocarbon receptor agonists present in tire extracts, Environ. Toxicol. Chem. 30, 1915-1925.
  • He, G., Tsutsumi, T., Zhao, B., Baston, D.S., Zhao, J., Heath-Pagliuso, S. and Denison, M.S. (2011) Third generation Ah receptor-responsive luciferase reporter plasmids: amplification of dioxin responsive elements dramatically increases CALUX bioassay sensitivity and responsiveness, Toxicol. Sci. 123, 511-522.
  • Van Langenhove, K., Croes, K., Denison, M.S., Elskens, M. and Baeyens, W. (2011) The CALUX Bio-assay: Analytical comparison between mouse hepatoma cell lines with a low (H1L6.1c3) and high (H1L7.5c1) number of dioxin response elements. Talanta 85, 2039-2046.
  • Elskens, M., Baston, D.S., Stumpf, C., Haedrich, J., Keupers, I., Croes, K., Denison, M.S., Baeyens, W. and Goeyens, L. (2011) CALUX measurements: statistical inferences for the dose response curve, Talanta 85, 1966-1973.
  • Croes, K., Van Langenhove, K., Den Hond, E., Bruckers, L., Colles, A., Koppen, G., Loots, I., Nelen, V., Schoeters, G., Nawrot, T., Can Larebeke, N., Denison, M.S. and Baeyens, W. (2011) Quantification of PCDD/Fs and dioxin-like PCBs in small amounts of human serum using the sensitive H1L7.5c1 mouse hepatoma cell line: validation and analysis of human serum samples from adolescents for the Flemish Human Biomonitoring campaign, Talanta 85, 2484-2491.
  • Addeck, A., Croes, K., Van Langenhove, K., Denison, M.S., Elskens, M. and Willy Baeyens (2012) Dioxin analysis in water by using a passive sampler and CALUX bioassay, Talanta 88, 73-78.
  • Croes, K., Vandermarken, T., Van Langenhove, K., Elskens, M., Desmedt, M., Roekens, E., Denison, M.S., Van Larebeke, N. and Baeyens, W. (2012) Analysis of PCDD/Fs and dioxin-like PCBs in atmospheric deposition samples from the Flemish measurement network: correlation between the CALUX bioassay and GC-HRMS, Chemosphere 88, 881-887.
  • Brander, S.M., He, G., Smalling, K.L., Denison, M.S. and Cherr, G.N. (2012) The in vivo estrogenic and in vitro anti-estrogenic activity of permethrin and bifenthrin, Environ. Toxicol. Chem. 31, 2848-2855.
  • Zhao, B., Bohonowych, J.E.S., Timme-Laragy, A., Jung, D., Affatato, A.A., Rice, R.H., Di Giulio, R.T. and Denison, M.S. (2013) Common commercial and consumer products contain activators of the aryl hydrocarbon (dioxin) receptor, PloS One 8 (2), e56860.
  • Magiatis, P., Pappas, P., Gaitanis, G., Mexia, N., Melliou, E., Galanou, M., Vlachos, C., Stathopoulou, K., Skaltsounis, A.L., Marselos, M., Velegraki, A., Denison, M.S. and Bassukas, I.D. (2013) Human symbiotic yeasts overproduce a collection of exceptionally potent activators of the Ah (dioxin) receptor in diseased skin, J. Invest. Dermatol., In Press.
  • Van den Berg, M., Denison, M.S., Birnbaum, L.S., DeVito, M., Fiedler, H., Falandysz, J., Rose, M., Schrenk, D., Safe, S., Tohyama, C., Tritscher, A., Tysklind, M. and R.E. Peterson, R.E. (2013) Polybrominated dibenzo-p-dioxins (PBDDs), dibenzofurans (PBDFs) and biphenyls (PBBs) - Inclusion in the toxicity equivalency factor concept for dioxin-like compounds, Toxicol. Sci., In Press.
  • Croes, K., Colles, A., Koppen, G., De Galan, S., Vandermarken, T., Govarts, E., Bruckers, L., Nelen, V., Schoeters, G., Van Larebeke, N., Denison, M.S., Mampaey, M. and Baeyens, W. (2013) Determination of PCDD/Fs, PBDD/Fs and dioxin-like PCBs in human milk from mothers residing in the rural areas in Flanders, using the CALUX bioassay and GC-HRMS, Talanta, In Press.