Biography Education Academic Positions Research Interests Present Research Present Students Courses Taught Memberships Grants Received Publications Back to Faculty

Alice Harmon, Ph.D.

Professor of Botany

• Molecular Biologist
• Signal Transduction
• 402 Cancer & Genetics Research Complex
• (352) 273-8096
• harmon@botany.ufl.edu

Biography

Dr. Harmon was born and raised in Ft. Pierce, Florida. Her family’s home is on Hutchison Island which is one of Florida’s many barrier islands on the Atlantic coast. Her interest in science developed at an early age, and she received her highschool’s science prize the year she graduated. She attended the University of Florida and majored in chemistry. Following graduation she worked as a technician for industry in California, the Environmental Protection Agency in Georgia, and an ecology research laboratory in South Carolina, and became a certified medical technologist in Georgia. Desiring a challenging career, she enrolled in graduate school in the Department of Biochemistry at the University of Georgia. Her mentor Dr. Milton Cormier introduced her to the study of calcium-binding proteins, and after graduation he encouraged her to take on a post-doctoral project dealing with plant protein kinases. Graduate student Cindy Putnam-Evans and she were the first to purify and characterize a member of the calcium-dependent protein kinase family. She’s been hooked on plants and protein kinases ever since and enjoys pursuing this work at the University of Florida.

Education

• Ph.D., University of Georgia, Biochemistry, 1985
• B.S., University of Florida, Chemistry 1970
• Ph.D. Dissertation Title: "Structure and Function of Calcium-Binding Proteins: Calmodulin, Calmodulin-Dependent NAD Kinase, and Prokaryotic Calcium-Binding Proteins"

Academic Positions

• 1984-1985 Post-Doctoral Associate, Dept. of Biochemisry, University of Georgia, Athens, GA
• 1985-1989 Assistant Biochemist, Dept. of Biochemistry, University of Georgia, Athens, GA
• 1989-1995 Assistant Professor, Dept. of Botany, University of Florida, Gainesville, FL
• 1991-Present Faculty Member, Graduate Degree Program in Plant Cell and Molecular Biology, University of Florida, Gainesville, FL
• 1994-Present Courtesy Joint Faculty, Dept. of Chemistry, University of Florida, Gainesville, FL
• 1995-2004 Associate Professor, Dept. of Botany, University of Florida, Gainesville, FL
• 2004-Present Professor, Dept. of Botany, University of Florida, Gainesville, Fl

Research Interests:

Plants respond to a variety of stimuli including light, growth regulators, touch, environmental stress, and pathogen attack. Many of the responses are brought about by an increase in intracellular free calcium concentration. My lab focuses on the molecular events that occur as a result of this change in calcium concentration. Specifically, we are studying a family of protein kinases whose activities are stimulated by calcium, and which are responsible for eliciting physiological changes. These protein kinases are called calcium-dependent protein kinases or CDPKs.

Present Research

Phosphorylation and Regulation of Soybean Serine Acetyltransferase 2.1. We have discovered a soybean protein, called serine acetyltransferase 2.1, that is phosphorylated by CDPK ( Liu et al., 2006 ). Serine acetyltransferases are enzymes that catalyze the first step in the biosynthesis of cysteine from serine. Serine acetyl transferase 2.1 (serat2.1) is phosphorylated at a single site (amino acid 378 in its sequence) by CDPK, and this phosphorylation prevents feedback inhibition by cysteine. Serat2.1 is phosphorylated in vivo in response to oxidative stress. We hypothesize that CDPK is activated via an increase in cellular calcium that results from stress, and it phosphorylates serat2.1. Since phosphorylated enzyme is not inhibited by cysteine, cellular levels of cysteine rise. Cysteine is a component of homoglutatione, a compound known to protect cells from reactive oxygen species. Thus calcium-stimulated activation of serat2.1 leads to protection of the cell from stress.

Association of CDPK with Oil Bodies in Seeds . Oil bodies are organelles that store oil (triacylglycerol), CDPK is localized with oil bodies in seeds from sandalwood, soybean, and Arabidopsis (Anil et al, 2000; 2003). We hypothesize that CDPK may play a regulatory role during the biogenesis of oil bodies during seed development, or it may be involved in mobilization of stored oil during early seedling growth.

Arabidopsis 2010 Project. This project focuses on the 34 genes that encode CDPKs in the model plant Arabidospis thaliana . Along with co-investigators, John Cushman and Jeff Harper (University of Nevada, Reno), Estelle Hrabak (University of New Hampshire), and Michael Sussman (University of Wisconsin, Madison), we have identified and characterized proteins that interact with CDPKs, and determined the subcelluar localization of the enzymes. In addition we are using mass spectrometry to investigate the substrate specificity and identify substrates of the CDPKs. Publications resulting from this project are:

Chen, S. and A.C. Harmon , (2006), Advances in Plant Proteomics, Proteomics in press
Dammann, C., Ichida, A., Hong, B.M., Romanowsky, S.M., Hrabak, E.M., Harmon, A.C., Pickard, B.G., and Harper, J.F . (2003). Subcellular targeting of nine calcium-dependent protein kinase isoforms from Arabidopsis. Plant Physiol 132, 1840-1848.
Harper JF, Breton G, Harmon AC , (2004). Decoding Ca 2+ signals through plant protein kinases, Annu Rev Plant Biol, 55:263-288
Harper, JF, and Harmon, A.C . (2005) Plants, Symbiosis, and Parasites: A Ca 2+ -signaling connection. Nat Rev Mol Cell Biol, 6:555-566
Hegeman, A.D., Harms, A.C., Sussman, M.R., Bunner, A. E., (2004) An isotope labeling strategy for quantifying the degree of phosphorylation at multiple sites in proteins, J Am Soc Mass Spectrom, 15, 647-653
Hegeman, A.D. M. Rodriguez, B.W. Han, Y. Uno, G.N. Phillips Jr., E.M. Hrabak, J.C. Cushman, J.F. Harper, A.C. Harmon, M.R. Sussman (2006) A Phyloproteomic Characterization of In Vitro Autophosphorylation in Calcium-Dependent Protein Kinases, Proteomics, 6:3649-3664
Hrabak, E.M., Chan, C.W., Gribskov, M., Harper, J.F., Choi, J.H., Halford, N., Kudla, J., Luan, S., Nimmo, H.G., Sussman, M.R., Thomas, M., Walker-Simmons, K., Zhu, J.K., and Harmon, A.C. (2003). The Arabidopsis CDPK-SnRK Superfamily of Protein Kinases. Plant Physiol 132, 666-680.
Milla M.A., Townsend, J., Chang I.F., and Cushman, J.C. (2006) The Arabidopsis AtDi19 gene family encodes a novel type of Cys2/His2 zinc-finger protein implicated in ABA-independent dehydration, high-salinity stress and light signaling pathways   Plant Mol Biol. 61:13-30
Milla, M.A.R, Uno, Y., Chang, I-F., Townsend, J., Maher, E., Quilici, D. Cushman, J.C . (2006) A novel yeast two-hybrid approach to identify CDPK substrates: Characterization of the interaction between AtCPK11 and At Di19, a nuclear zinc finger protein. FEBS Lett. 580:904-911.
Strachan, C.N., Stevens, S.M., Jr, Hrabak, E.M., Winefordedner, J.D., Denslow, N.D., and Harmon, A.C ., (submitted) Investigation of the Autophosphorylation Sites of a Calcium- Dependent Protein Kinase by Various Mass Spectrometric Methods
Wang D, Harper JF, Gribskov M., (2003) Systematic Trans-genomic Comparison of Protein Kinases between Arabidopsis thaliana and Saccharomyces cerevisiae. Plant Physiol 132:2152-2165

Present Students

Michael Boniface (undergraduate)
Amit Barbar (undergraduate)

Courses Taught:

• BOT 6516 Plant Metabolism
• CHM 4304 Chemical Aspects of Cellular Control
• BSC 2010 Integrative Biology

Membership in Professional Organizations:

• American Association of Plant Physiologists

Grants received

• USDA NRI CSREES “ GmSerat2;1 and Its Regulation by Phosphorylation in Sulfur Metabolism of Soybean”
• NSF - "Developing Paradigms for Functional Genomics of Protein Kinases and Phosphoproteins Using the CDPK Superfamily"

Selected Publications

Harper, J.F., Bretton, G. and A.C. Harmon, 2004, Decoding Ca 2+ signals through plant protein kinases, Annu. Rev. Plant Biol. 55:263-288

Harper, J.F. and A.C. Harmon, 2005, Plants, Symbiosis, and Parasites: A Calcium Signaling Connection, Nature Rev. Mol. Cell Biol. 6:555-566

Stevens, S.M., Jr., A.Y. Chung, M.C. Chow, S.H. McClung, C.N. Strachan, A.C. Harmon, N.D. Denslow, and L Prokai, 2005, Enhancement of phosphoprotein analysis using a florescent affinity tag and mass spectrometry. Rapid Commun. Mass Spec. 19:2157-2162

Hegeman, A.D. M. Rodriguez, B.W. Han, Y. Uno, G.N. Phillips Jr., E.M. Hrabak, J.C. Cushman, J.F. Harper, A.C. Harmon, M.R. Sussman A phyloproteomic characterization of in vitro autophosphorylation in calcium-dependent protein kinases, Proteomics, 6:3649-3664

Chen, S. and A.C. Harmon, 2006, Advances in Plant Proteomics, Proteomics

Liu, F., B.-C. Yoo, J.-Y. Lee, W. Pan, and A.C. Harmon 2006 Calcium-regulated phosphorylation of soybean serine acetyltransferase in response to oxidative stress, J. Biol. Chem. 281:27405-27415

>> top

Have a Question? Contact us.
Last Updated 6/28/05
Site maintenance and Feedback
Holloway@Botany.UFL.EDU