Metalloenzymes catalyze key biogeochemical reactions that allow life to sustain itself on Earth. In the marine environment, microbial communities produce the metalloenzymes that influence carbon cycling, nitrogen cycling, and organic matter degradation, for example. Yet the oceans are extraordinarily depleted in many biologically important metals: iron, cobalt, nickel, copper, and zinc are found at nanomolar or lower concentrations in surface waters. Due to the analytical challenges associated with these low abundances, our understanding of how the scarcity of metals affects metalloenzyme biosynthesis and the corresponding biogeochemical cycles is in its infancy. Important questions have yet to be answered: what are the distributions of key metalloenzymes and their microbial hosts? How are metalloenzyme distributions governed by metal and oxygen distributions? How do those abundances affect biogeochemical processes such as primary production, denitrification, and carbon remineralization? How will climate change affect many biogeochemical processes catalyzed by metalloenzymes?
In this project we are applying cutting-edge proteomic technology towards experiments on biogeochemically relevant microbial isolates under varying environmental conditions and the development of a quantitative field metalloenzyme capability to explore the distribution of these proteins and their relationships to biological and chemical features.
Alysia D. Cox and Mak A. Saito. Proteomic responses of oceanic Synechococcus WH8102 to phosphate and zinc scarcity and cadmium additions. Frontiers in Microbiological Chemistry.
Abigail E. Noble, Dawn M. Moran, Andrew E. Allen, and Mak A. Saito. Dissolved and particulate trace metal micronutrients under the McMurdo Sound seasonal sea ice: basal sea ice communities as a capacitor for iron. In press at Frontiers in Microbiological Chemistry.
Erin M. Bertrand, Dawn M. Moran, Matthew R. McIlvin, Jeffrey M. Hoffman, Andrew E. Allen, and Mak A. Saito. Methionine synthase interreplacement in diatom cultures and communities and the persistence of B12 use by eukaryotic phytoplankton. 58:4. 1431-1450. Limnology and Oceanography.
Saito, M.A., A.E. Noble, A. Tagliabue, T. J. Goepfert, C.H. Lamborg, W.J. Jenkins. 2013. A Large Hydrothermal Iron Plume in the South Atlantic and Implications for Global Iron Cycling. Nature Geosciences.
J. Daphne Aguirre, Hillary M. Clark, Matthew McIlvin, Christine Vazquez, Shaina L. Palmere, Dennis Grab, J. Seshu, Mak A. Saito and Valeria C. Culotta. 2013. A Manganese-Rich Environment Supports Superoxide Dismutase Activity in the Lyme Disease Pathogen, Borrelia burgdorferi. Journal of Biological Chemistry.
Robbins, L.J., S.V. Lalonde, M.A. Saito, N.J. Planavsky, A.M. Mloszewska, E. Pecoits, C. Scott, C.L. Dupont, A. Kappler, and K.O. Konhauser. 2013. Authigenic iron oxide proxies for marine zinc over geological time and implications for eukaryotic metallome evolution. Geobiology.
Moore, C.M., Mills, M.M., Arrigo, K.R., Berman-Frank, I., Bopp, L., Boyd,P.W., Galbraith, E.D., Geider, R.J., Guieu, C., Jaccard, S.L., Jickells, T.D., LaRoche, J., Lenton, T., Mahowald, N.M., Marañón, E., Marinov, I., Moore,J.K., Nakatsuka, T., Oschlies, A., Saito, M.A., Thingstad, T.F., Tsuda, A., and Ulloa, O. 2013. Processes and patterns of Ocean Nutrient Limitation. Nature Geosciences. 6 702-710
Mackey, KRM, K Caldiera, A Grossman, D Moran, M McIlvin, A Paytan, & M Saito. Effect of temperature on photosynthesis and growth in diverse marine Synechococcus strains. Plant Physiology.
Bertrand EM, Allen AE, Dupont CL, Norden-Krichmar T, Bai J, Saito MA. 2012. Impact of Cobalamin Starvation on Diatom Molecular Physiology and the Identification of a Novel Cobalamin Acquisition Protein. Proc. Nat. Acad. Sci.
Katherine RM Mackey, Kathryn Roberts, Michael W Lomas, Mak A Saito, Anton F Post, Adina Paytan. 2012. Variable solubility and ecological impact of atmospheric phosphorus deposition. Environ. Sci. Technol.
Mak A. Saito. 2012. The Rise of Oxygen and Aerobic Biochemistry. Structure. 20:1. 1–2.
Noble, A.E., C.H. Lamborg, D. Ohnemus, P.J. Lam, K. T.J. Goepfert, C.I. Measures, C.H. Frame, K.L. Casciotti, G.R.DiTullio, J. Jennings, and M.A. Saito. 2012. Basin-scale plumes of cobalt, iron, and manganese emanating from the Benguela-Angola front in the South Atlantic Ocean. 57:4. 989-1010. Limnology and Oceanography.
Sonya T. Dyhrman, Bethany D. Jenkins, Tatiana A. Rynearson, Mak A. Saito, Melissa L. Mercier, Harriet Alexander, LeAnn P. Whitney, Andrea Drzewianowski, Vladimir V. Bulygin, Erin M. Bertrand, Zhijin Wu, Claudia Benitez-Nelson, Abigail Heithoff. 2012. Coordination in the transcriptome and proteome of the diatom Thalassiosira pseudonana reveals a diverse phosphorus stress response. PLoS One. 7:3. e33768.
Saito, M.A., Vladimir Bulygin, Dawn Moran, Craig Taylor, and Christopher Scholin. 2011. Examination of Microbial Proteome Preservation Techniques Applicable to Autonomous Environmental Sample Collection. Front. Microbio. 2:215.
Living Lab Live radio interview, National Public Radio WCAI, June 3, 2013
Media interviews regarding South Atlantic Hydrothermal Iron Plume Study August 2013. New York Times – Science Times, Die Weld (Germany), ScienceDaily, La Gran Epoca (Spain). http://www.whoi.edu/news-release/new-source-of-iron
Lyme disease metalloprotein (lack of iron requirement) press release: http://www.whoi.edu/oceanus/viewArticle.do?id=164849
Oceanus article on Diazotroph Proteomic Research: http://www.whoi.edu/oceanus/feature/recycling-rare-essential-nutrients-in-the-sea
Oceanus article on Vitamin B12 Claw and Proteomics: https://www.whoi.edu/oceanus/archives
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