Figure The coupling of Stachel activated GPR56 and BFPP associated
mutations of the receptor with Gα11.
The effect of BFPP mutations on β-Arrestin
recruitment
It was previously reported that NTF truncated human GPR56 from amino
acids 1–342 gave enhanced interactions with β-arrestin compared to the
full-length receptor [36]. In this work, GPR56 or BFPPmutants of the receptor were co-expressed with β-arrestin
(Rluc8-arrestin3-Sp1) and GRK-based biosensors [30] to assess the
effect of each mutation on the β-arrestin recruitment, upon receptor
activation with the Stachel peptide. For this, HEK293 cells were
treated with 1mM P7 Stachel peptide and β-arrestin recruitment
was measured as a BRET signal. The arrestin biosensor assay utilized in
this study gave increased plasma membrane recruitment for the NTF
truncated GPR56 however stimulation of wild-type receptor orBFPP mutants with the Stachel peptide did not lead to any
measurable recruitment.