Education

Ph.D. University of Texas-Austin 1983

Research interests

How do cells respond to extracellular stimuli? What are the components of a cell's response system and how are these components regulated? Cell stimulus response systems are referred to as Signal Transduction Pathways. A common eukaryotic signal transduction pathway is the G protein-mediated pathway in which G proteins link cell surface receptors to the appropriate effector (response) systems

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We use techniques in cell biology, biochemistry, and molecular biology to examine G protein-mediated signal transduction. The soil amoebae, Dictyostelium is employed and serves as a model system for examining the roles G proteins play in cell physiology.

In Dictyostelium discoideum, a single G protein a-subunit, Ga2, controls entry into the developmental phase of the cell's life cycle. Ga2 regulates three different effector systems; guanylyl cyclase, adenylyl cyclase and phospholipase C. How activation of each effector occurs through Ga22 and how this translates into the developmental process is being examined. Present research aims to understand how covalent modification of Ga2 by phosphate, myristate and palmitate regulate Ga2 function.

 

Publications

• Gundersen, R.R., You, J., Rauch, S., Farnham, K., McCarty, C., Willis, N. and Prince, A. 2005 Loss-of-function mutations identified in the Helical domain of the G protein a-subunit, Ga2, of Dictyostelium discoideum. Biochim. Biophys. Acta 1722; 262-270.
• Root, P.A., Prince, A., and Gundersen, R.E. 1999 Aggregation of Dictyostelium discoideum is dependent on myristoylation and membrane localization of the G protein a-subunit, Ga2. J. Cell. Biochem. 74: 301-311.
• Gundersen, R.E. 1997 Phosphorylation of the G protein a-subunit, Ga2, of Dictyostelium discoideum requires a functional and activated Ga2. J. Cell. Biochem. 66:268-276.
• Brazill, D.T., Gundersen, R.E., and Gomer, R.H. 1997 A cell-density sensing factor regulates the lifetime of a chemoattractant-induced Ga-GTP conformation. FEBS Lett. 404;100-104.
• Srinivasan, J., Gundersen, R.E., and Hadwiger, J.A. 1999 Activated Ga subunits can inhibit multiple signal transduction pathways during Dictyostelium development. Developmental Biology 215: 443-452.
• Son, M., Gundersen, R.E. and Nelson, D.L. 1993 A Second Member of the Novel Ca2+-dependent Protein Kinase Family from Paramecium tetraurelia: Purification and Characterization. J. Biol. Chem. 268, 5940-5948.
• Wu, L-J., Gaskins, C., Gundersen, R.E., Hadwiger, J.A. Johnson, R.L., Pitt, G.S., Firtel, R.A.and Devreotes, P.N. 1993 Signal Transduction by G Proteins in Dictyosleium discoideum. In: Handbook of Experimental Pharmacology: GTPase in Biology II. (eds. B. Dickey and L. Birnbaumer) Berln, NY: Springer-Verlag Publication 335-349.
• Johnson, R. L., Gundersen, R.E., Herald, D., Pitt, G.S., Tugendreich, S., Saxe, C.L., Kimmel, A.R.and Devreotes, P.N. 1992 G protein-linked Signaling Pathways Mediate Develoment in Dictyostelium. In: The Cell Surface. Cold Spring Harbor Symposium of Quantitative Biology. Vol. LVII, pp. 169-176.
• Gundersen, R.E. and Devreotes, P.N. 1990 In vivo Receptor Mediated Phosphorylation of a G Protein in Dictyostelium. Science 248, 591-593.
• Pitt, G.S., Gundersen, R.E.and Devreotes, P.N. 1990 Mechanisms of Excitation and Adaptation in Dictyostelium. Seminars in Cell Biology 1, 99-104.
• Chen, M.Y., Devreotes, P.N.and Gundersen, R.E. 1994 Serine-113 is the Site of Receptor-Mediated Phosphorylation of the Dictyostelium G Protein a-subunit, Ga2. J. Biol. Chem. 269, 20925-20930.

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