Fig. 4

Binding and effect of DN10 and DN13 on mGlu2 containing heterodimers. a Scheme illustrating the approach used to detect binding of the c-Myc-tagged nanobodies on mGlu2 heterodimers containing either SNAP-mGlu3 or SNAP-mGlu4 labeled with SNAP-Lumi4-Tb. b and c TR-FRET signal measured as a function of the concentration of nanobody on cells expressing mGlu2 and SNAP-mGlu3 (b) or SNAP-mGlu4 (c). d Scheme illustrating the approach used to specifically detect the activation of mGlu2-3 or mGlu2-4 heterodimers, as based on the co-expression of SNAP-mGlu3 or SNAP-mGlu4 with CLIP-mGlu2, labeled respectively with SNAP-Lumi4-Tb and CLIP-Green. e and f TR-FRET signal measured as a function of the concentration of glutamate on cells expressing CLIP-mGlu2 and SNAP-mGlu3 (e) or SNAP-mGlu4 (f). Data are expressed as percent of the signal obtained with DN1 in the presence of agonist (b, c), or percent of the maximal agonist-induced change in FRET (e, f). Data are mean ± SEM of 3 independent experiments performed in triplicates