John Cox, Ph.D.
858 Madison Ave.
101F Molecular Science Building
Memphis, TN 38163
Our laboratory is interested in defining how multi-membrane spanning transporters and channels are restricted to specialized membrane domains within cells. To address this question we have investigated the molecular mechanisms involved in directing the intracellular trafficking of variant chicken AE1 anion exchangers. These electroneutral anion exchangers are involved in regulating intracellular pH and cell volume in erythroid and kidney epithelial cells. Studies from our laboratory have shown that fifteen variant transcripts are derived from the AE1 gene in chickens. The polypeptides encoded by the variant transcripts differ only at the N-terminus of their cytoplasmic domains, the region of the polypeptide known to interact with elements of the cytoskeleton. A variety of approaches have indicated that the alternative N-terminal cytoplasmic domains serve as sorting signals to direct these variant transporters to specialized membrane compartments within cells. In addition, we have demonstrated a role for both the actin and the ankyrin/spectrin-based cytoskeleton in directing the localization and stability of these membrane transporters. Recent analyses have shown that the association of AE1 variants with the ankyrin/spectrin-based cytoskeleton is regulated by casein kinase 2, which constitutively associates with ankyrin. Current studies are investigating how specific extracellular stimuli modulate the activity of this kinase, which appears to be a critical regulator of anion exchanger function.
- 1975 B.S. in Biology, Department of Biology, University of Illinois, Chicago
- 1977 M.S. in Biology, Department of Biology, University of Illinois, Chicago
- 1983 Ph.D. in Cell Biology, Department of Biology, University of
Advisor: Dr. Joanna B. Olmsted
Dissertation: "Human anticentromere antibodies: Distribution, characterization of antigens, and effect on microtubule organization"