Molecular and Cell Biology
Education: Ph.D. University of Michigan, Postdoctoral study, Stanford University.
Research Interests: My lab is interested in how microorganisms regulate their molecular and cellular activities when growing and developing in close association with other species. It is clear that interactions among microbes, and between microbes and multicellular organisms, are quite common outside of the laboratory. These interactions may be beneficial to the species involved, as in the case of mutualistic symbiosis. Alternatively, the association may be detrimental to one of the species as is the case during pathogenic microbe-host interactions.
The bacterium Sinorhizobium meliloti is able to establish a symbiosis with its host plant, alfalfa, during which the bacteria enter root cells, differentiates, and fixes atmospheric nitrogen into ammonium, thereby providing the host with a biologically available form of this element. This interaction requires that gene expression and growth of both organisms be integrated in order for the symbiosis to be productive. The research being conducted in my lab is aimed at better understanding how the integration between S. meliloti and its host is achieved. Studying this symbiosis as a model system should reveal general mechanisms of interspecies communication, and mechanisms for integrating gene function and metabolism when microbes live in close association with one another, as is most often the case in natural situations.
Garcia, P. P. Bringhurst, R.M. and D. J. Gage (2010). Characterization of a two-component regulatory system which regulates succinate-mediated catabolite repression in Sinorhizobium meliloti.
J. Bacteriol 192: 5725-5735.
Sheftic, S. R., Garcia, P. P., Robinison, V. L., Gage, D. J. and A. T. Alexandrescu (2010) NMR Assignments for the Sinorhizobium meliloti Response Regulator Sma0114.
Biomolecular NMR Assignments Published online: DOI 10.1007/s12104-010-9266-1
C. Arango-Pinedo and D. J. Gage (2009) HPrK regulates succinate-mediated catabolite repression in the Gram negative symbiont Sinorhizobium meliloti.
J. Bacteriol. 191:298-309
Gage, D. J., Herron, P. M., Arango-Pinedo, C., and Z. G. Cardon (2008). Live reports from the soil grain–the promise and challenge of microbiosensors.
Functional Ecology 22:983.
Arango-Pinedo, C., Bringhurst, R.M. and D. J. Gage (2008). Sinorhizobium meliloti mutants lacking phosphotransferase system enzyme HPr or EIIA are altered in diverse processes, including carbon metabolism, cobalt requirements, and succinoglycan production.
J. Bacteriol. 190:2947
Z. Cardon and D. J. Gage (2006) Resource exchange in the rhizosphere – molecular tools and the microbial perspective.
Ann. Rev. Ecology, Evolution and Systematics 37: 459-488
H. Monahan, C. Arango-Pinedo and D. J. Gage (2006) Architecture of infection thread networks in developing root nodules. Plant Physiology 140: 661-670
D. J. Gage (2004) Infection and invasion of roots by symbiotic, nitrogen-fixing, rhizobia during nodulation of temperate legumes.
Microbiol. Mol. Biol. Rev. 68:280-300
M. Rosado and D. J. Gage. (2003) Transcriptional control of a rRNA promoter of the nodulating symbiont Sinorhizobium meliloti.
FEMS Microbiol. Letters 226:15-22
D. J. Gage (2002) Analysis of infection thread development after coinoculation of alfalfa with gfp-and Dsred-expressing Sinorhizobium meliloti
J. Bacteriology 184:7042-7046
Bringhurst, R. M. and D. J. Gage (2002) Inducer exclusion/expulsion plays a key role in succinate-mediated catabolite repression in Sinorhizobium meliloti.
J. Bacteriology 184:5385-5392
Bringhurst, R. M., Cardon, Z., and D. J. Gage (2000). Galactosides in the rhizosphere: utilization by Sinorhizobium meliloti and development of a biosensor. Proc. Nat. Acad. Sci. 98:4540-4545
Gage, D. J., and W. Margolin. (2000). Hanging by a thread: invasion of legume plants by rhizobia. Current Opinion in Microbiology 3:316
Bringhurst, R. M., and D. J. Gage (2000) An AraC-like transcriptional activator is required for induction of genes needed for a-galactoside utilization in Sinorhizobium meliloti. FEMS Microbiol. Letters 188:23-27
Gage, D. J., and S. R. Long. (1998) a-galactoside uptake in Rhizobium meliloti: isolation and characterization of agpA, a gene encoding a periplasmic binding protein required for melibiose and raffinose utilization. J. Bacteriology 180: 5739 – 5748
Gage, D. J., Bobo, T. and S. R. Long. (1996). Use of green fluorescent protein to visualize the early events of symbiosis between Rhizobium meliloti and alfalfa, Medicago sativa. J. Bacteriology 178:7159
Gage, D.J., and F.C. Neidhardt. (1992). Adaptation of Escherichia coli to an uncoupler of oxidative phosphorylation, 2,4-dinitrophenol. J. Bacteriology 175: 7105
Gage, D.J., and F.C. Neidhardt. (1992). Modulation of the heat shock response by one-carbon metabolism in Escherichia coli. J. Bacteriology 175: 1961.