CaMello-XR enables visualization and optogenetic control of G signals and receptor trafficking in GPCR-specific domains.

The signal specificity of G protein-coupled receptors (GPCRs) including serotonin receptors (5-HT-R) depends on the trafficking and localization of the GPCR within its subcellular signaling domain. Visualizing traffic-dependent GPCR signals in neurons is difficult, but important to understand the contribution of GPCRs to synaptic plasticity. We engineered CaMello (Ca-melanopsin-local-sensor) and CaMello-5HT for visualization of traffic-dependent Ca signals in 5-HT-R domains.