Dring N. Crowell, Ph.D.

Professor

E-mail address: crowdrin@isu.edu
Office Phone: (208) 282-3171
Fax: (208) 282-4570
Gale Life Science Building
Office: LS 416
Lab : LS 417

Crowell Lab Home Page
Keywords: plant molecular biology, plant biochemistry, genetic engineering of crop species

Education

Ph.D. (1987) Biochemistry, University of Wisconsin, Madison, WI
B.S. (1981) Chemistry, Illinois State University, Normal, IL

Biographical Sketch

Dr. Crowell joined the Department of Biological Sciences in 2008 after 17 years as a faculty member at Indiana University – Purdue University Indianapolis (IUPUI). He received a B.S. degree in Chemistry from Illinois State University in 1981 and a Ph.D. degree in Biochemistry from the University of Wisconsin-Madison in 1987. Dr. Crowell’s dissertation research was focused on the molecular genetics of lipid A biosynthesis in Escherichia coli. Dr. Crowell received postdoctoral training at the University of Wisconsin-Madison under the direction of Dr. Richard Amasino, where he became interested in molecular mechanisms of plant growth and development. His postdoctoral research was focused on the mechanisms of action of the plant growth factor cytokinin, which promotes release of lateral meristems, chloroplast development, and cell division. Like many of the major plant growth factors (e.g., abscisic acid, gibberellin, brassinolide), cytokinin is an isoprenoid compound and this connection between plant growth factor function and isoprenoid biosynthesis has been the focal point of Dr. Crowell's research program for nearly two decades. Among other contributions, Dr. Crowell demonstrated protein isoprenylation in plants, which is the process by which certain proteins are covalently attached at a carboxyl terminal cysteine residue to a fifteen or twenty carbon isoprenoid. In addition, Dr. Crowell demonstrated that isoprenylated proteins are further modified by carboxyl methylation. Using Arabidopsis thaliana as a model plant, Dr. Crowell cloned and identified two genes encoding enzymes responsible for the methylation of isoprenylated proteins and one gene encoding the enzyme responsible for the selective removal of this methyl group. Recent work has been focused on the metabolism of isoprenylcysteine compounds in plants and the role of reversible methylation of isoprenylated proteins in regulating the plant response to abscisic acid. Studies from Dr. Crowell’s lab have demonstrated that over-methylation of isoprenylated proteins attenuates abscisic acid signaling and, in so doing, causes a drought sensitive phenotype. Conversely, under-methylation of isoprenylated proteins promotes abscisic acid signaling and causes a drought resistant phenotype. This work has clear agricultural significance and current research projects include genetic engineering of potato and soybean plants for drought tolerance via targeted alterations in isoprenylcysteine methylation and demethylation.

Dr. Crowell has published over 40 peer-reviewed journal articles and book chapters and his research program has received continuous support from the National Science Foundation and U.S. Department of Agriculture since 1993.

Teaching

Genetics 358 (Spring)
Senior Seminar 491/492 (Spring)
Principles of Molecular Biology 610 (Fall)
Graduate Seminar 691/692 (Fall)

Selected Publications

Crowell, D. N., Kadlecek, A. T., John, M. C., and Amasino, R. M. (1990) Cytokinin-induced mRNAs in cultured soybean cells. Proc. Natl. Acad. Sci. USA 87: 8815-8819.

Randall, S. K., Marshall, M. S., and Crowell, D. N. (1993) Protein isoprenylation in suspension-cultured tobacco cells. Plant Cell 5: 433-442.

Biermann, B. J., Morehead, T. A., Tate, S. E., Price, J. R., Randall, S. K., and Crowell, D. N. (1994) Novel isoprenylated proteins identified by an expression library screen. J. Biol. Chem. 269: 25251-25254.

Crowell, D. N., Sen, S. E., and Randall, S. K. (1998) Prenylcysteine a-carboxyl methyltransferase in suspension-cultured tobacco cells. Plant Physiol. 118: 115-123.

Crowell, D.N., and Kennedy, M. (2001) Identification and functional expression in yeast of a prenylcysteine a-carboxyl methyltransferase gene from Arabidopsis thaliana. Plant Mol. Biol. 45: 469-476.

Zheng, Z.-L., Nafisi, M., Tam, A., Li, H., Crowell, D. N., Chary, S. N., Schroeder, J. I., Shen, J., and Yang, Z. (2002) Plasma membrane-associated ROP10 small GTPase is a specific negative regulator of abscisic acid responses in Arabidopsis. Plant Cell 14: 2787-2797.

Chary, S. N., Bultema, R. L., Packard, C. E., and Crowell, D. N. (2002) Prenylcysteine a-carboxyl methyltransferase expression and function in Arabidopsis thaliana. Plant J. 32: 735-747.

Crowell, D. N., Packard, C. E., Pierson, C. A., Giner, J.-L., Downes, B. P., and Chary, S. N. (2003) Identification of an allele of CLA1 associated with variegation in Arabidopsis thaliana. Physiol. Plant. 118: 29-37 (cover article).

Johnson, C. D., Chary, S. N., Chernoff, E. A., Zeng, Q., Running, M. P., and Crowell, D. N. (2005) Protein geranylgeranyltransferase I is involved in specific aspects of abscisic acid and auxin signaling in Arabidopsis thaliana. Plant Physiol. 139: 722-733.

Deem, A. K., Bultema, R. L., and Crowell, D. N. (2006) Prenylcysteine methylesterase in Arabidopsis thaliana. Gene 380(2): 159-166.

Downes, B. P., Saracco, S. A., Lee, S. S., Crowell, D. N., and Vierstra, R. D. (2006) MUBS: a family of ubiquitin-fold proteins that are plasma membrane-anchored by prenylation. J. Biol. Chem. 281 (37): 27145-27157 (cover article).

Crowell, D. N., Huizinga, D. H., Deem, A. K., Trobaugh, C., Denton, R., and Sen, S. E. (2007) Arabidopsis thaliana plants possess a specific farnesylcysteine lyase that is involved in detoxification and recycling of farnesylcysteine. Plant J. 50 (5): 839-847.

Huizinga, D. H., Omosegbon, O., Omery, B., and Crowell, D. N. (2008) Isoprenylcysteine methylation and demethylation regulate abscisic acid signaling in Arabidopsis. Plant Cell 20: 2714-2728.

Crowell, D. N., and Huizinga, D. H. (2009) Protein isoprenylation: the fat of the matter. Trends Plant Sci. 14(3): 163-170.

Gerber, E., Hemmerlin, A., Hartmann, M., Heintz, D., Hartmann, M.-A., Mutterer, J., Rodriguez-Concepcion, M., Boronat, A., van Dorsselaer, A., Rohmer, M., Crowell, D. N., and Bach, T. J. (2009) The plastidial 2C-Methyl-D-Erythritol 4-Phosphate Pathway Provides the Isoprenyl Moiety for Protein Geranylgeranylation in Tobacco BY-2 Cells. Plant Cell 21: 285-300.