Areas of Interest
Our long term goals have been the correlation of surface
membrane macromolecular diffusional dynamics with cell (or
membrane) function, and the development of new approaches for
evaluating diffusional dynamics parameters for both lipids and
proteins. Fluorescence redistribution after photobleaching
(FRAP), total internal reflection FRAP (TIR-FRAP), fluorescence
correlation spectroscopy (FCS), single particle tracking (SPT),
and confocal microscopy methods have been used to establish
macromolecular distribution and mobility characteristics. These
approaches were utilized to examine the diffusional behavior of
such seemingly diverse systems as membrane proteins on sperm
cell surfaces, thy-1 antigen on the surface of 3T3 fibroblasts,
the distribution and diffusional dynamics of EGF receptor and
the ICAM-1 adhesion molecule on fibroblast and endothelial cell
surfaces. Work has concentrated on two specific areas: the
factors that restrict and control the rate of lateral diffusion
of integral membrane proteins and lipids; and the mechanisms
that produce and maintain specialized domains on the surfaces of
differentiated cells. It is expected that such studies will
continue to give new insight into the structural organization of
the cell, and the dynamics of intracellular interactions.
Selected Publications
Cowan, AE. Olivastro E. M. Koppel DE. Loshon CA. Setlow B.
Setlow P. Lipids in the inner membrane of dormant spores of
Bacillus species are largely immobile Proceedings of the
National Academy of Sciences of the United States of America.
2004 In press.
Cowan AE. Koppel DE. Setlow B. Setlow P. A soluble protein is
immobile in dormant spores of Bacillus subtilis but is mobile in
germinated spores: implications for spore dormancy. [Journal
Article] Proceedings of the National Academy of Sciences of
the United States of America. 100(7):4209-14, 2003.
Cowan AE. Koppel DE. Vargas LA. Hunnicutt GR. Guinea pig
fertilin exhibits restricted lateral mobility in epididymal
sperm and becomes freely diffusing during capacitation.
Developmental Biology. 236(2):502-9, 2001. |
