In both vertebrates and invertebrates heterotrimeric G proteins play a critical role during asymmetric cell division
by controlling cell polarisation and mitotic spindle orientation. During asymmetric cell division, the activation of G
proteins depends on GoLoco domain containing proteins. One such protein is Partner of Inscuteable (Pins) in
Drosophila. Pins forms a complex with the G-alpha subunit of heterotrimeric G proteins and is thereby thought to
locally activate G-beta/gamma signalling. Using the asymmetric cell division of the Drosophila sensory organ
precursor (pI) as an experimental model, I will use two complementary approaches to reach a better understanding
of how G proteins function during asymmetric cell division: 1) I will characterise recently identified Pins interactor
proteins to better understand how the Pins/G-alpha complex regulates both cell polarity and mitotic spindle
positioning 2) I will apply the novel flurophore assisted laser inactivation (FALI) technology, which allows the
spatially and temporally controlled inactivation of proteins, to directly address whether G-beta/gamma signalling is
locally activated by the Pins/G complex. The conservation of heterotrimeric G proteins across species and the
importance of asymmetric cell division during both development and adult life warrant that my results will be of
wider interest in the fields of developmental and cell biology. Furthermore, establishing the FALI technology in the
pI cell will be a valuable tool to investigate mechanisms regulating cell polarization.