V-004 | Identification of proteins that interact with the C-terminal end of Gpm6a through the amino acid residue E258

Cellular and Molecular Neurobiology
Author: Sebasttián Cabré Brosio | Email: scabrebrosio@estudiantes.unsam.edu.ar

Sebastián Cabré Brosio^1°, Beata Fuchsova^1°

^1° Instituto de Investigaciones Biotecnológicas, Escuela de Bio y Nanotecnologías (EByN), Universidad Nacional de San Martín (UNSAM) – Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), San Martín, Buenos Aires, Argentina

Gpm6a is a neuronal membrane glycoprotein associated with different psychiatric diseases and chronic stress response. It acts in processes of neuroplasticity such as filopodia formation, neurite extension, or synaptogenesis. However, its mechanism of action is not well understood. Gpm6a induces extensive formation of filopodia and the amino acid E258 is necessary for this process. At the same time, its mutation decreases the amount of Gpm6a on the cell surface and increases its accumulation in the intracellular compartments that we identified as Lamp1-positive endosomes, indicating that protein trafficking is affected. Since trafficking of membrane proteins in neurons is related to differentiation, growth, signaling and neuronal plasticity, it is of great relevance to study the role of the residue E258. We hypothesize that E258 plays a crucial role in Gpm6a intracellular trafficking with relevance to neuronal morphogenesis. We assume that by mutating this residue, the interaction of the C-terminal end of Gpm6a with proteins that can mediate its neuroplastic function is lost. Therefore, the objective of the present work is to identify proteins that interact with the C-terminal end of Gpm6a through the amino acid residue E258. Using mass spectrometry, I aim to identify the factors that differentially interact with the wild-type protein and its mutated form E258A employing coimmunoprecipitation assays from lysates of cells that overexpress wild-type Gpm6a and its mutant E258A.