Douglas A. Gage

University Administrator Responsibilities

Assistant to Vice President, Office of the Vice President for Research and Graduate Studies

Research Interests

The primary area of interest in our laboratory is the biosynthesis and function of plant osmoregulatory compounds, in particular betaines and their sulfonium analogs. To help plants adjust to salt or drought stress, these zwitterionic "compatible osmolytes" can accumulate in the cytoplasm to concentrations of more than 1M without disrupting cellular function. The mechanism by which enzymes and cellular proteins are protected from denaturation in these high concentrations is not well understood.

Our work is currently focused on the osmolyte dimethylsulfoniopropionate (DMSP). In addition to its role in physiological adaptation, DMSP is one of the primary contributors to biogenic sulfur in the atmosphere through its breakdown to dimethylsulfide, a gas whose atmospheric oxidation products are important in cloud formation and potentially in climate regulation. Our biosynthetic studies have determined that this compound is derived from methionine via two distinct pathways in higher plants and marine algae. We are using stable isotope and radioisotope labeling methods to identify intermediates in these pathways. Isolation and characterization of the enzymes involved in DMSP biosynthesis is one near-term objective of this work. A longer term goal is to understand how this pathway is regulated under different environmental conditions, both in the context of plant adaptation to stress and global sulfur cycles.

A second focus of the research in our laboratory is on the development of new analytical methods employing mass spectrometry to characterize protein structure. MORE

Recent Publications

Robosky LC, Wade K, Woolson D, Baker JD, Manning ML, Gage DA, Reily MD. 2008. Quantitative evaluation of sebum lipid components with nuclear magnetic resonance. J Lipid Res. Mar;49(3):686-92.

Molloy MP, Donohoe S, Brzezinski EE, Kilby GW, Stevenson TI, Baker JD, Goodlett DR, Gage DA. 2005. Large-scale evaluation of quantitative reproducibility and proteome coverage using acid cleavable isotope coded affinity tag mass spectrometry for proteomic profiling. Proteomics. 5(5):1204-8.

Froehlich JE, Wilkerson CG, Ray WK, McAndrew RS, Osteryoung KW, Gage DA, Phinney BS. 2003. Proteomic study of the Arabidopsis thaliana chloroplastic envelope membrane utilizing alternatives to traditional two-dimensional electrophoresis. J Proteome Res. 2(4):413-25.

Kocsis MG, Ranocha P, Gage DA, Simon ES, Rhodes D, Peel GJ, Mellema S, Saito K, Awazuhara M, Li C, Meeley RB, Tarczynski MC, Wagner C, Hanson AD. 2003. Insertional inactivation of the methionine s-methyltransferase gene eliminates the s-methylmethionine cycle and increases the methylation ratio. Plant Physiol. 131(4):1808-15.

Hoffmann-Benning S, Gage DA, McIntosh L, Kende H, Zeevaart JA. 2002. Comparison of peptides in the phloem sap of flowering and non-flowering Perilla and lupine plants using microbore HPLC followed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Planta. 216(1):140-7. Epub 2002 Nov 12.

MacLeod KJ, Husain RD, Gage DA, Ahn K. 2002. Constitutive phosphorylation of human endothelin-converting enzyme-1 isoforms. J Biol Chem. 277(48):46355-63. Epub 2002 Sep 18. MORE