Structurele en ruimtelijke analyse van de adhesie G-proteïne-gekoppelde receptor GPR125/ADGRA3

The aim of this PhD project is to characterize the structure/function relationship of the orphan adhesion G protein-coupled receptor GPR125/ADGRA3. We will investigate the function of the C-terminal fragment (CTF), the N-terminal fragment (NTF) and compare it with the full-length receptor (FL) which is a complex of the CTF and NTF. The NTF is an organized extracellular protein that possibly interacts with unidentified extracellular interaction partners. The CTF is a 7-transmembrane (7TM) receptor which may signal akin to other 7TM receptors. Little is known about these functional connections. An initial goal is to produce labelled native-like NTF fragments and to screen broadly for their interactions with various tissues. For the CTF it is known that it is difficult to study its coupling to signaling cascades and therefore we will employ impedance studies as a holistic readout of signaling. We will study the signaling capacity of the CTF alone as well as the FL receptor and various combinations with NTF variants. Finally, we will attempt to delineate how the subcellular localization of GPR125 is regulated. We will attempt to compare the studied properties of GPR125 in adapted laboratory cell lines with more natural tissue backgrounds.