2. Venture laboratory, Kyoto Institute of Technology.
3. Insect Biomedical Research Center, Kyoto Institute of Technology.
Background: Mutations of some components of the Dystrophin Glycoprotein Complex (DGC) are known to cause Muscular Dystrophy in humans. An innovative approach to the further understanding of pathological mechanisms and physiological roles of the DGC has been recently made using several non-mammalian animal models, using species such as Caenorhabditis elegans, Xenopus laevis, and zebrafish. The mammalian DGC is in most part conserved in Drosophila, with respect to the amino acid sequence. However, detailed comparisons of the characteristic properties of each DGC components between mammals and Drosophila have yet to be made.
Methods: In the present study, we analyzed mutual binding ability of Drosophila Sarcoglycans in order to address the possibility of complex formation, a characteristic of the mammalian counterparts.
Results: In vitro binding assays showed that Drosophila Sarcoglycans could mutually bind to each other. Moreover, β-Sarcoglycan and α-Sarcoglycan could directly associate with Epidermal growth factor receptor (EGFR) via the EGF-like consensus sequences of their C-terminus regions.
Conclusions: In vitro data in combination with immunohistochemical data for sarcoglycan knockdown fly retinae, we propose that Sarcoglycan complex formation is required for eye development. Notably, the direct binding of β-Sarcoglycan and δ-Sarcoglycan to EGFR might be critical for the proper regulation of EGFR signaling during eye development in Drosophila.
Keywords: Sarcoglycan, Drosophila, EGFR, muscular dystrophy, eye development.