686A Poster - 10. Cell biology: Cytoskeleton, organelles and trafficking
Thursday April 07, 2:00 PM - 4:00 PM

Authors:
Colleen Maillee; Dan Bergstralh

Affiliation: University of Rochester

Keywords:
t. cell junctions and adhesion; r. cell-cell interactions

Epithelial cells are linked together by adherens junctions, which are largely responsible for cell-cell adhesion, and occluding junctions, which form a barrier to paracellular diffusion. Our published results show that another epithelial adhesion module, comprised of Ig-domain adhesion proteins – Neuroglian/L1CAM, Fasciclin II/NCAM, and a three Ig-domain protein, either Fas3 (insects) or potentially CADM1 (vertebrates) – helps to maintain epithelial integrity during proliferation by ensuring that the tissue grows as a monolayer. These factors are not only found in proliferating epithelia, where they can localize along the length of the cell-cell border, but also in the vertebrate excitatory synapse and Drosophila neuromuscular junction. Furthermore, they have been extensively studied in both flies and mammals for their role in axon guidance. We want to know how they work. L1CAM is evolutionarily conserved at the sequence level, and the function of its cytoplasmic domain is well studied. Remarkably, whereas the extracellular C-terminal structures for NCam/Fas2 and CADM1/Fas3 are similar, their cytoplasmic N-termini are not. These findings suggest conservation of function without conservation of sequence. We are using phylogenetic analysis, structural prediction algorithms, and Drosophila genetics to study this problem.