Dennis, Edward
Biochemistry: phospholipase A2, signal transduction in macrophages, lipid maps, prostaglandin regulation, mass spec of lipids and proteins.

Contact Information
Professor of Chemistry and Biochemistry
Professor of Pharmacology

Office: BSB 4076
Phone: 858-534-3055
Email: edennis@ucsd.edu
Web: cobra.ucsd.edu
Group: View group members
Education
1968 Ph.D., Harvard University
1965 M.A., Harvard University
1963 B.A., Yale University
Appointments
1969 Postdoc, Harvard Medical School
1967 Predoc, Harvard University
Awards and Academic Honors
2003-
Editor-in-Chief, Journal of Lipid Research
2000
Amer. Soc. Biochemistry and Molecular Biology Avanti Award
1983-1984
Guggenheim Fellow
Research Interests
Our laboratory is leading the national NIGMS LIPID MAPS Glue Grant Consortium which is developing LC/MS based lipidomics analysis to map the lipidome by detecting and quantizing the numerous molecular species of lipids in the murine macrophage. We are determining the lipid changes upon cell stimulation by various agonists such as TLR receptor agonists. Our laboratory is focused on identifying the known and discovering new fatty acids and eicosanoid metabolites (prostaglandins and leukotrienes) in these cells and using LC/MS to follow their production upon cell stimulation and determining lipid metabolite fluxes at the cellular level.

Historically, our laboratory has focused on discovering the regulation of lipid second messengers and signal transduction processes and especially the role of various phospholipases in their generation. Special attention is paid to the cytosolic, secreted, and membrane-bound phospholipase A2s (PLA2) responsible for the control of eicosanoid biosynthesis in macrophage cells. These molecules are produced from arachidonic acid released by PLA2 upon cell stimulation. Our goal is to characterize and elucidate the regulatory mechanisms of various phospholipase A2s both in vitro and in the intact cell and the LC/MS lipidomics efforts are currently being utilized to study their regulation.

PLA2s are currently receiving a great deal of attention because they include the smallest (molecular weight 13,000) and perhaps the simplest enzymes of complex lipid metabolism known and are ideally suited for in vitro mechanistic studies. PLA2s have several kinds of phospholipid binding sites including activator sites, interfacial sites, and catalytic sites. It is important to define the precise role of the amino acid residues involved in their interactions with phospholipids. Our laboratory is now utilizing mass spectrometric deuterium exchange analysis (HD/MS) to map the surface interactions of various pure recombinant human PLA2s with phospholipids.

Our laboratory also designs and synthesizes chemical inhibitors of phospholipase A2. Many different inhibitor classes have been developed and are being studied using in vitro, ex vivo and in vivo animal models. In summary, our laboratory utilizes organic synthetic approaches, enzyme kinetics, molecular biology,, cell and tissue culture, and mass spectrometric techniques as well as traditional biochemical approaches in attacking phospholipase and membrane problems.

Primary Research Area
Biochemistry
Interdisciplinary interests
Cellular Biochemistry

Selected Publications