Alexander Mohr's research while affiliated with University of Leipzig and other places

Elucidation of protein interactions in living cells is a critical step in deciphering pharmacological targets. Here, we apply an orthogonal labeling approach to G protein‐coupled receptors by two peptide pairs, interacting through coiled‐coil motifs. The rapid reporter introduction in a one‐pot reaction allows the investigation of transient and proximity‐dependent interplay of different receptor proteins at the cell membrane. Focusing on prominent cardiovascular receptors, present in heart and blood vessel tissue, distinct receptor–receptor interactions have been identified that modulate intracellular signaling cascades. More information can be found in the Full Paper by A. G. Beck‐Sickinger et al.

Fine‐tuning of G protein‐coupled receptor (GPCR) signaling is important to maintain cellular homeostasis. Recent studies demonstrated that lateral GPCR interactions in the cell membrane can impact signaling profiles. Here, we report on a one‐step labeling method of multiple membrane‐embedded GPCRs. Based on short peptide tags, complementary probes transfer the cargo (e. g. a fluorescent dye) by an acyl transfer reaction with high spatial and temporal resolution within 5 min. We applied this approach to four receptors of the cardiovascular system: the endothelin receptor A and B (ETAR and ETBR), angiotensin II receptor type 1, and apelin. Wild type‐like G protein activation after N‐terminal modification was demonstrated for all receptor species. Using FRET‐competent dyes, a constitutive proximity between hetero‐receptors was limited to ETAR/ETBR. Further, we demonstrate, that ETAR expression regulates the signaling of co‐expressed ETBR. Our orthogonal peptide‐templated labeling of different GPCRs provides novel insight into the regulation of GPCR signaling.