G protein-coupled receptors (GPCRs) are vital signal transducers that upon activation become phosphorylated on intracellular serine and threonine residues. However, GPCR phosphorylation is very unstable during routine immunohistochemical procedures, necessitating the presence of appropriate phosphatase inhibitors throughout both fixation and staining procedures. We have therefore developed a protocol that facilitates the visualization of GPCR activation in response to physiological and pharmacological stimulation.
Fritzwanker S, Nagel F, Kliewer A, Schulz S. In situ Visualization of therapeutic drug effects using phosphosite-specific GPCR antibodies. bioRxiv 2022.06.14.496067; doi: https://doi.org/10.1101/2022.06.14.496067
Figure 1. In situ visualisation of µ-opioid receptor activation.
Figure 2. In situ visualisation of CB1 cannabinoid receptor activation.