Erik Floor

Erik Floor
  • Emeritus Professor

Contact Info


Ph.D., University of California, Davis, 1969

My research is on the cellular and molecular causes of aging. I am interested especially in how aging affects the nervous system and focus on Parkinson's disease, the second most common cause of neurological disability in later life. The neurons that degenerate in Parkinson¹s disease use dopamine as their neurotransmitter, and it is thought that dopamine itself interacts with other cell components to trigger neural degeneration in a small brain region that controls voluntary movement, the substantia nigra. For reasons that are unclear, the nigra is one of the few brain regions that accumulate high levels of iron. Dopamine and iron share the property of being readily oxidizable under normal physiological conditions. Abnormal oxidation is believed to contribute to neuronal loss in Parkinson¹s disease and also to the slower loss of dopamine neurons in the nigra that occurs over the life span even in normal individuals.

The precise role of aberrant oxidation in aging, or in the nigra, is not yet known. All cell components are vulnerable. We analyze free radical damage to brain proteins by various techniques (amino acid analysis, size-exclusion HPLC, 2D gel electrophoresis, immunoblotting, mass spectrometry) in combination with cell culture models to understand how dopamine neurons manage oxidative stress. The goal is to discover how dopamine neurons are damaged by free radicals and, eventually, to develop an antioxidant therapy to preserve these vulnerable cells.

Selected Publications

Representative Publications

Floor E., Maples A. M., Rankin C.A., Yaganti V. M., Shank S. S., Nichols G. S., O'laughlin M., Galeva N. A., Williams T. D. 2006. A one-carbon modification of protein lysine associated with elevated oxidative stress in human substantia nigra. J Neurochem. 97, 504-514. Find Article Online.

Wacker M. J., Wilhelm H. L., Gomez S. E., Floor E. and Orr J. A. (2003) The role of serotonin in the thromboxane A2-induced coronary chemoreflex. Am. J. Physiol. Heart Circ. Physiol. 284, H867-H875.

Jin H., Wu H., Osterhaus G., Wei J., Davis K., Sha D., Floor E., Hsu C.-C., Kopke R. D., and Wu J.-Y. (2003) Demonstration of functional coupling between g-aminobutyric acid (GABA) synthesis and vesicular GABA transport into synaptic vesicles. Proc. Natl. Acad. Sci. USA 100, 4293-4298. Epub 2003 Mar 12.

Floor E. and M. G. Wetzel. 1998. Increased protein oxidation in human substantia nigra pars compacta in comparison with basal ganglia and prefrontal cortex measured with an improved dinitrophenylhydrazine assay. J. Neurochem. 70, 268-275.Find Article Online.

Wang Y. and E. Floor. 1998. Hydrogen peroxide inhibits the vacuolar H+-ATPase in brain synaptic vesicles at micromolar concentrations. J. Neurochem. 70, 646-652. Find Article Online.

Berwin, B., E. Floor, and T.F.J. Martin 1998. CAPS (mammalian UNC-31) protein localizes to membranes involved in dense-core vesicle exocytosis. Neuron 21: 137-145. Find Article Online.

Jeng, C.-J., S. McCarroll, T.F.J. Martin, E. Floor, J. Adams, D. Krantz, S. Butz, R. Edwards, and E.S. Schweitzer. 1998. Thy-1 is a component common to multiple populations of synaptic vesicles. J. Cell Biol. 140: 685-698. Find Article Online.

Efthimiopoulos S., Floor E., Georgakopoulos A., Shioi J., Cui W., Yasothornsrikul S., Hook V. Y. H., Wisnieski T., Buee L. and Robakis N. K. 1998. Enrichment of presenilin 1 peptides in neuronal large dense-core and somatodendritic clathrin-coated vesicles. J. Neurochem. 71:2365-2372. Find Article Online.

Hsu C.-C., Davis K. M., Jin H., Foos T., Floor E., Chen W., Tyburski J. B., Yang C.-Y., Schloss J. V. and Wu J.-Y. 2000. Association of L-glutamic acid decarboxylase to the 70-kDa heat shock protein as a potential anchoring mechanism to synaptic vesicles. J. Biol. Chem. 275:20822-20828. Find Article Online.

Floor E. 2000. Iron as a vulnerability factor in nigrostriatal degeneration in aging and Parkinson's disease. Cell. Mol. Biol. 46:709-720. Find Article Online.

Rankin C. A., Joazeiro C. A. P., Floor E., and Hunter T. 2001. Parkin has E3 ubiquitin-protein ligase activity mediated by C-terminal RING elements. J. Biomed. Sci. 8:421-429. Find Article Online.

Davies S., Elliott M. H., Floor E. , Truscott T. G., Zareba M., Sarna T., Shamsi F. A. and Boulton M. E. 2001. Phototoxicity of lipofuscin in human retinal pigment epithelial cells. Free Radic. Biol. Med. 31, 256-265. Find Article Online.


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