Eugene A. Nothnagel
Professor of Plant Physiology

Plant Biochemistry and Molecular Biology Physical Biochemistry Ph.D., Cornell University, Ithaca, New York, 1981 Postdoctoral Fellow, University of Colorado, Boulder, Colorado, 1981-1983 VOICE: 951-827-3777 FAX: 951- 827-4437 MAIL: eugene.nothnagel@ucr.edu

Plant cell surface components play important functional roles in cell division, cell growth, and other developmental and physiological events in plants. The principal research effort in our laboratory aims toward elucidating the physicochemical properties of the plasma membrane-cell wall interface and evaluating the role of these properties relative to cell division and growth. Our current focus is on arabinogalactan-proteins, a class of proteoglycans that exist in the cell wall and on the plasma membrane. Our investigations have shown that perturbation of these molecules on the surface of suspension-cultured cells leads to a potent inhibition of cell division which is reversible with some cell types but not with others. Ongoing work includes the biochemical isolation and structural characterization of arabinogalactan-proteins and identification of other macromolecules that interact with arabinogalactan-proteins at the cell surface. Our recent results show that most arabinogalactan-proteins carry a glycosylphosphatidylinositol lipid substituent that serves to anchor the proteoglycan to the plasma membrane. This lipid anchor is readily cleaved, apparently by a phospholipase C or D, to release the arabinogalactan-protein from the membrane. These and other observations are relevant to our overall goal of determining if arabinogalactan-proteins and their interactive neighbors form part of a signal transduction pathway that may function in the control of cell division and other processes.

Our research in these areas is carried out in our laboratory as well as through use of the resources in several special centers and facilities on the UCR campus including the Center for Plant Cell Biology; the Institute for Integrative Genome Biology; the High Resolution Mass Spectrometry Facility; and the NMR Facility.

SELECTED PUBLICATIONS
Guan, Y. and Nothnagel, E.A. Binding of arabinogalactan proteins by Yariv phenylglycoside triggers wound-like responses in Arabidopsis cell cultures. Plant Physiol. 135:1346-1366 (2004).

Svetek, J., Yadav, M. P. and Nothnagel, E. A. Presence of a glycosylphosphatidylinositol lipid anchor on rose arabinogalactan proteins. J. Biol. Chem. 274:14724-14733 (1999).

Serpe, M. D. and Nothnagel, E. A. Arabinogalactan-proteins in the multiple domains of the plant cell surface. Adv. Bot. Research 30:207-289 (1999).

Nothnagel, E.A. Proteoglycans and related components in plant cells. Int. Rev. Cytol. 174:195-291 (1997).

Langan, K.J. and Nothnagel, E.A. Cell surface arabinogalactan-proteins and their relation to cell proliferation and viability. Protoplasma 196:87-98 (1997).

Serpe, M.D. and Nothnagel, E.A. Heterogeneity of arabinogalactan-proteins on the plasma membrane of rose cells. Plant Physiol. 112:1261-1271 (1996).

Serpe, M.D. and Nothnagel, E.A. Fractionation and structural characterization of arabinogalactan-proteins from the cell wall of Rose cells. Plant Physiol. 109:1007-1016 (1995).

Serpe, M.D. and Nothnagel, E.A. Effects of Yariv phenylglycosides on Rosa cell suspensions: Evidence for the involvement of arabinogalactan-proteins in cell proliferation. Planta 193:542-550 (1994).

Komalavilas, P., Zhu, J.-K. and Nothnagel, E. A. Arabinogalactan-proteins from the suspension culture medium and plasma membrane of rose cells. J. Biol. Chem. 266:15956-15965 (1991).