Associate Professor of Biology
Areas of expertiseCellular neurobiology, nerve degeneration/regeneration, heat shock proteins, tight junction physiology, Claudin-3
PhD, University of Texas at Austin 1989
BS, Southwestern University 1982
August 01, 1997 - present
Chair, Department of Biology
August 01, 2002 - July 01, 2008
Inaugural Paideia Professor
August 01, 2003 - May 01, 2007
Faculty for the 21st Century
September 01, 1995 - April 01, 2000
University of Texas at Austin
January 01, 1990 - August 01, 1994
Methods in Cellular/Molecular Biology
My current area of research is the study of tight junction physiology. I work in collaboration with Southwestern colleagues, Dr. Maria Cuevas and Dr. Maria Todd, to investigate the role of claudin-3 in tight junction formation and maintenance in breast cancer cell lines. I compare the paracellular resistance of MCF-7 cells, which express high levels of claudin-3, with the paracellular resistance of siRNA transfected MCF-7 cells, which have suppressed claudin-3 expression. I also investigate the subcellular localization of claudin-3. Claudin-3 is one of approximately 24 claudin proteins involved in the formation of tight junctions between epithelial cells (Turksen and Troy, 2004). The claudin proteins are recently discovered (Furuse, et al., 1998), small (22-24 kDa) transmembrane proteins that interact with occludin and junction adhesion molecules to form tight junctions. Claudins regulate paracellular resistance by regulating which solutes diffuse between the cells of an epithelial monolayer.
Prior to this current work, I performed investigations in the area of cellular neurobiology to seek strategies to improve nerve axon regeneration. These investigations were performed in the model organisms, crayfish and squid, and in tissue culture using PC12 cells. Much of my work in cellular neurobiology involved the biochemical analysis of proteins, such as heat shock proteins, and the measurement of electrical events in neurons. I now use similar skills to investigate tight junctions.
I enjoy participating in the intellectual development of students. I try to make the learning process fun for a class by forming a bridge between students and the information they seek to learn, by providing memorable analogies and models, and by playing music. In my courses, I provide examples of the depth and breadth of a topic and emphasize the main ideas that students will be expected to know at their next level of education or employment. I design my courses to be rigorous and I provide much support to sincerely try to help all students succeed. Courses that I teach at Southwestern include Organ Physiology, Neurobiology, Cell Biology, and Biology of Perception.
Sheller, R.A., M.E. Smyers, R.M. Grossfeld, M.L. Ballinger, and G.D. Bittner. 1998. Heat shock proteins in axoplasm: high constitutive levels and transfer of inducible isoforms from glia. J Comp Neurol, 396: 1-11.
Sheller, R.A., M. Tytell, M.Smyers, and G.D. Bittner. 1995. Glia-to-axon communication: enrichment of glial proteins transferred to the squid giant axon. J. Neurosci. Res., 41: 324-334.
Sheller, R.A. and G.D. Bittner. 1992. Maintenance and synthesis of proteins for an anucleate axon. Brain Res., 580: 68-80.
Representative Abstracts with Student Researchers
Fernandez, M. and R.A. Sheller. 2006. Ubiquitin and Heat Shock Proteins in the Severed Ventral Nerve Cord of the Crayfish, Procambarus Clarkii. Texas Academy of Science Annual Meeting.
Nordin, A. and R.A. Sheller. 2006. Stress Proteins in crayfish Ventral Nerve Cords Exposed to High Temperature, Severance, Ethanol, and UV Exposure. Texas Academy of Science Annual Meeting.
Bhaleeya, S. and R.A. Sheller. 2001. The effect of exogenous heat shock proteins on the crayfish ventral nerve cord. Texas Academy of Science Annual Meeting.
Leontaritis, N. and R. A. Sheller. 2001. Possible aspartame-induced stress response and apoptotic cell death in the crayfish central nervous system. Texas Academy of Science Annual Meeting.
Seminars & Presentations
Recent poster presentations:
Sheller, R.A., Cuevas, M.E., and Todd, M.C. 2009. Overexpression of claudin-3 in a breast cancer cell line. ASCB Abstr.
Todd, M.C., Cuevas, M.E., and Sheller, R.A. 2009. Overexpression of claudin-3 protein in breast cancer cell lines. AACR Proceedings
Sheller, R.A. 2007. Biology of Perception for Non-Biology Undergraduates. Soc. Neurosci. Abstr.
Honors & Awards
Andrew W. Mellon Foundation Scholarly Grant, 2008 and 2010
Sam Taylor Award, 2004
Southwestern Teaching Award, 2003
Research Opportunity Award (NSF), 2002
Groups & Affiliations
American Society for Cell Biology
Society for Neuroscience
National Association of Biology Teachers
Project Kaleidoscope: Faculty for the 21st Century