Role of the Sara endosome during asymmetric cell division

• Applicant: Professor Dr. Marcos A. González Gaitán
• Subject Area: Cell Biology
• Term: from 2001 to 2009
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 5330820

In this proposal we plan to perform a molecular genetic analysis of polarized endocytic trafficking in epithelial cells to study its role during morphogenetic signaling. During morphogenetic signaling, a distinct group of cells produce a secreted morphogen which traffics through the developing tissue and forms a concentration gradient that instructs the receiving cells about their position within the primordium. We discovered a novel mechanism of gradient formation whereby the Drosophila Dpp morphogen traffics across the target tissue by intracellular planar transcytosis, rather than diffusing freely through the extracellular space. Dpp is secreted apically, but appears basally at the extracellular space. Furthermore, its trafficking through the receiving cells involves an apical endosomal compartment, reminiscent of the "subapical compartment" (SAC). The SAC have been proposed as a key endosomal compartment during polarized traffic in epithelial cells. Prompted by these observations, in the present research project we will focus in three topics: i) Which factors control polarized traffic in epithelial cells? ii) How polarized traffic control epithelial cell polarity? iii) Which role does polarized traffic play during Dpp planar transcytosis?

• DFG Programme: Priority Programmes
• Subproject of: SPP 1111: Cell Polarity