Juan Luis Jurat-Fuentes

Professor

UT

Research

Research in the Jurat-Fuentes laboratory is focused on the insect digestive system as a target for biological pesticides and as a source of novel enzymes with biotechnological applications.  Specific research areas include the characterization of the mode of action and mechanisms of insect resistance against Cry toxins from Bacillus thuringiensis (Bt), the characterization of the insect gut healing mechanism as a model for epithelial regeneration, and the identification of cellulases from insects for biofuel applications.  In our work we use gel-based proteomics, functional assays (RNAi), cell culture expression, and other protein-protein interaction techniques to answer questions related to bacterial toxin-insect gut interactions and the insect digestive physiology.  Basic outcomes from our research include the characterization of the gut epithelial regeneration in insects, the pathophysiology of bacterial toxins in insects, and increasing our understanding of how insects digest lignocellulosic biomass.  The expected applied outcomes from our research include the improvement of insect pathogens as biocontrol agents, development of Bt resistance management and monitoring strategies, development of new pest control approaches, and the identification of novel enzymes and growth factors to allow development of new cell culturing techniques and to improve cost-effectiveness of lignocellulosic biofuels.

Description of Research

Cry toxins produced by the bacterium Bacillus thuringiensis (Bt) are the most successful insect pathogen commercially developed as bioinsecticide.  These toxins are also expressed in transgenic BT crops to control insects while increasing crop yields and reducing the need for chemical pesticide applications.  In this context, our research uses both proteomic and functional genomic approaches to identify and characterize the crucial molecules involved in Cry toxin pathogenesis and the resistance mechanisms insects may develop to overcome susceptibility to these bacterial toxins.  More recently, our interest has been focused on characterizing enhanced gut epithelium regeneration as a mechanism of resistance to Cry toxins.  This process is controlled by proliferation and differentiation of stem cells after intoxication of mature cells.  Our research is attempting to uncover the specific signals regulating this process and how these signals are altered in some insects displaying and enhanced regenerative response to intoxication.  The applied goal for this research is the optimization of these pathogens as efficient, environmentally sound, pest control methods, as well as the characterization of the insect gut epithelium response to pathogenic attack.

Herbivorous insects are notorious pests of diverse crops and can use a wide range of lignocellulosic substrates as source of energy.  This ability to use lignocellulosic biomass as food suggests that the digestive system in these insects has evolved efficient lignocellulolytic systems.  The digestive system of herbivorous insects presents in some cases extreme pH and reducing conditions resembling some of the biorefinery processes.  Based on these observations, our research is focused on identifying and characterizing novel cellulolytic enzymes from insect digestive fluids that can be incorporated in the biotechnological transformation of raw plant material to biofuel.  Novel, more efficient cellulose-degrading enzymes would greatly reduce costs of production of lignocellulosic ethanol, allowing it to be competitive against fossil fuels.  After an initial screening for cellulolytic activity in multiple local and foreign insect species, we are focusing on cloning enzymes from insects displaying high cellulolytic activity.  We plan to express these enzymes in heterologous systems and characterize their activity so that we can evaluate their use in lignocellulosic ethanol biofuel production.

Education

• Ph.D.: Entomology- University of Georgia (2002)
• M.S.: Genetics- Universitat de Valencia, Valencia, Spain (1997)
• B.S.: Biology - Universitat de Valencia, Valencia, Spain. (1995)

Publications

Willis, J. D., Klingeman, W., *Oppert, C., Oppert, B., and J. L. Jurat-Fuentes (2010) “Characterization of cellulolytic activity from digestive fluids of Dissosteira carolina (Orthoptera: Acrididae)” Comp. Biochem, Physiol. B Biochem. Mol. Biol. 157(3): 267-272

Willis, J. D., *Oppert, C., and J. L. Jurat-Fuentes (2010) “Methods for discovery and characterization of cellulolytic enzymes from insects” Insect Sci. 17(3):184-198.

Ning, C., Wu, K., Liu, C., Gao, Y., Jurat-Fuentes, J. L., and X. Gao (2010) “Characterization of a Cry1Ac toxin-binding alkaline phosphatase in the midgut from Helicoverpa armigera (Hübner) larvae”.  J. Insect Physiol. 56(6):666-672.

Oppert, C., Klingeman, W., *Willis, J. D., Oppert, B., and J. L. Jurat-Fuentes (2010).  “Prospecting for cellulolytic activity in insect digestive fluids”.  Comp. Biochem. Physiol. B, 155B(2):145-154

Fabrick J., *Oppert C., Lorenzen M. D., Morris K., Oppert B., and J. L. Jurat-Fuentes (2009).  “A novel Tenebrio molitor cadherin is a functional receptor for Bacillus thuringiensis Cry3Aa toxin”.  J. Biol. Chem., 284(27):18401-18410.

Perera, O.P., Willis, J.D., Adang, M.J., and J.L. Jurat-Fuentes (2009) “Cloning and characterization of the Cry1Ac-binding alkaline phosphatase (HvALP) from Heliothis virescens” Insect Biochem. Molec. Biol. 39(4): 294-302.

Chen, J., Hua, G., Jurat-Fuentes, J.L., Abdullah, M.A., and M. J. Adang (2007) “Synergism of Bacillus thuringiensis toxins by a fragment of a toxin-binding cadherin” Proc. Natl. Acad. Sci. USA 104(35): 13901-13906.

Jurat-Fuentes, J.L., and M.J. Adang (2007) “A proteomic approach to study Cry1Ac binding proteins and their alterations in resistant Heliothis virescens larvae”.  J. Inv. Pathol. 95(3): 187-191.

Krishnamoorthy, M., Jurat-Fuentes, J.L., McNall, R.J., Andacht, T., and M J. Adang (2007) “Identification of novel Cry1Ac binding proteins in midgut membranes from Heliothis virescens using proteomic analyses”.  Insect Biochem. Molec. Biol., 37(3): pp. 189-201.

Jurat-Fuentes J. L., and M. J. Adang (2006) “The Heliothis virescens cadherin protein expressed in Drosophila S2 cells functions as a receptor for Bacillus thuringiensis Cry1A, but not Cry1Fa toxins”.  Biochemistry, 45(32): pp. 9688-9695.