Jung Choi, Associate Professor; Faculty Program Director, Director of Bioinformatics Masters Degree Program
Ph.D., Biology, University of California, 1983
Email:
Phone: 404-894-8423
Fax: 404-894-0519
Office: Cherry Emerson (CE) 213
Research Interests
Plant molecular genetics, protein kinases and cell surface proteins in plant development and regeneration.
Current Research
Diverse Plant Protein Kinases with Calmodulin-Like Domains
Plants respond to many stimuli such as drought, heat, cold, hormones, insects, and pathogens with intracellular calcium fluxes. These calcium signals are then decoded by a diverse family of calcium-dependent protein kinases (CDPKs) with calmodulin-like domains. The question, then, is how the CDPKs generate appropriate responses to these different stimuli that all evoke calcium as a second messenger.
Our work with CDPKs began with a CDPK isoform and a CDPK-related kinase (CRK) cloned from carrot somatic embryos, and has continued with new CRK isoforms cloned from the model plant, Arabidopsis thaliana. CDPK431 is a canonical CDPK with 4 EF-hands in its calmodulin- like domain (Suen and Choi, 1991). CRK421 has no consensus EF-hand motifs (Lindzen and Choi, 1995). We are looking at possible modes of regulation of these kinases, by calcium, lipids, membrane localization, and interactions with other proteins. Long-term, we are also interested in characterizing specific substrates for these kinases.
Recent Publications
Zhang, X.S. and J.H. Choi, 2001. Molecular evolution of calmodulin-like domain protein kinases in plants and protists. J. Mol. Evol. 53:214-224.
Farmer, P.K. and J.H. Choi, 1999. Calcium and phospholipid activation of a recombinant calcium-dependent protein kinase (DcCPK1) from carrot (Daucus carota L.), Biochim. Biophys. Acta 1434:6-17.
Lindzen, E. and J.H. Choi, 1995. A carrot cDNA encoding an atypical protein kinase homologous to plant calcium-dependent protein kinases. Plant Mol. Biol. 28:785-797.
Koontz, D.A. and J.H. Choi, 1993. Protein phosphorylation in carrot somatic embryos in response to abscisic acid. Plant Physiol. Biochem. 31:95 102.
Bradburne, J.A., P. Godfrey, J.H. Choi and J.N. Mathis, 1993. In vivo labeling of Escherichia coli cell envelope proteins with N hydroxysuccinimide esters of biotin. Appl. Environ. Microbiol. 59:663 668.
Koontz, D.A. and J.H. Choi, 1993. Evidence for developmentally regulated phosphorylation of tubulin in carrot suspension cells. Physiol. Plantarum. 87:576 583.
Suen, K.L. and J.H. Choi, 1991. Isolation and sequence analysis of a cDNA clone for a carrot calcium dependent protein kinase: homology to calcium/calmodulin depenent protein kinase and to calmodulin. Plant Mol. Biol. 17:581 590.
Borkird, C., J.H. Choi, Z. Jin, G. Franz, P. Hatzopoulos, R. Chorneau, U. Bonas, F. Pelegri and Z.R. Sung, 1988. Developmental regulation of embryonic genes in plants. Proc. Natl. Acad. Sci. USA 85:6399 6403.
Choi, J.H., L. S. Liu, C. Borkird and Z.R. Sung, 1987. Isolation of cDNA clones for rare embryo specific antigens in carrot cell cultures. Proc. Natl. Acad. Sci. USA 84:1906 1910.
Borkird, C., J. Choi and Z.R. Sung, 1986. The effect of 2,4 D on expression of the embryogenic program in carrot. Plant Physiol. 81:1143 1146.