Dr. Sheridan has a long-standing research interest in gap junctions and their role in intercellular communication. Over the years he worked on a variety of systems and organisms, e.g. chick, amphibian, and fish embryos; tumors and tumor cells in culture; endothelium and other vascular cells ex vivo and in culture; and pancreatic islets. Certain themes are common to many of these studies, e.g. the quantitative relationship between gap junction structure and permeability; the function of gap junctions in development; the role of gap junctions in normal and abnormal cell growth; the process and regulation of gap junction formation; and the involvement of gap junctions in cell-cell signaling.
Dr. Sheridan's current research involves a reestablished collaboration with Ross Johnson, a faculty colleague in GCD. One major focus is on the regulation of gap junction assembly in model cell culture systems, with a particular emphasis on trafficking of gap junction hemichannels to the cell surface. His primary role in the project has been to develop quantitative digital imaging methods for studying the permeability of membrane hemichannels. Methods for studying the dynamics of dye leakage and uptake through hemichannels have been devised, based on earlier work in Dr. Sheridan's lab on gap junctional dye permeability. They will be used ultimately to evaluate the effects of various experimental andnatural regulators on the trafficking process.
Another focus is on the role of gap junctions in the development of the Zebrafish notochord. The studies have uncovered some intriguing, and unprecedented, patterns of gap junctional dye permeability in different regions of the notochord.These patterns can be modified by selective knock-down of specific connexins(gap junction proteins) by injection of connexin morpholinos, which also producessome distinctive phenotypes. The goal is to learn more about how the gap junction patterns in the notochord relate to its function as an axial organizer.
Selected Publications (Pubmed Search)
Sheridan, J.D., Evenson, K, and R.G. Johnson. (2003) A new dye-leakage approach to estimating membrane permeance of Cx43-hemichannels. International Gap Junction Conference, Cambridge, UK (poster)
Johnson, R.G., R.A. Meyer, X.-R. Li, D. Preus, L. Tan, H.Y. Li, A.F. Paulson, D.W. Laird and J. Sheridan (2002) Gap junctions assemble in the presence of cytoskeletal inhibitors, but enhanced assembly requires microtubules. Exper. Cell Res. 275:67-80.
TenBroek, E.M., Sheridan, J.D., and R.G. Johnson (2001) Characterization of an in vitro system for studying of the role of connexins in maintaining myocardial cell beat synchrony. International Gap Junction Conference, Hawaii (poster and B on the right)
Sheridan, J.D., Krufka, A., Hackett, P.B. and R.G. Johnson (2000) Gap junction communication in the developing zebrafish notochord. Zebrafish Development & Genetics, Cold Spring Harbor (poster)
Biegon, R.P., Atkinson, M.M., Liu, T.-F., Kam, E.Y., and J.D. Sheridan (1987) Permeance of Novikoff hepatoma gap junctions: quantitative video analysis of dye transfer. J. Membrane Biol. 96:225-233.
Atkinson, M.M., Anderson, S.K., and J.D. Sheridan (1986) Modification of gap junctions in cells transformed by a temperature-sensitive mutant of Rous Sarcoma virus. J. Membrane Biol. 91:53-64.
Sheridan, J.D., Finbow, M.E., and J.D. Pitts (1979) Metabolic interactions between animal cells through permeable intercellular junctions. Exper. Cell Res. 123:111-117.
Sheridan, J.D., Hammer-Wilson, M., Preus, D. and R.G. Johnson (1978) Quantitative analysis of low-resistance junctions between cultured cells and correlation with gap-junctional areas. J Cell Biol, 76:532-544.
Sheridan, J.D. (1971) Low-resistance junctions between cancer cells in various solid tumors. J. Cell Biol. 45:91 - 99.( Abstract of this paper selected for inclusion in Cancer Year Book, 1971)