Send to

Choose Destination
Proc Natl Acad Sci U S A. 2006 Jun 20;103(25):9691-6. Epub 2006 Jun 9.

Knockin mice expressing fluorescent delta-opioid receptors uncover G protein-coupled receptor dynamics in vivo.

Author information

Institut de Génétique et de Biologie Moléculaire et Cellulaire, CNRS/INSERM, Université Louis Pasteur, 1 Rue Laurent Fries, 67404 Illkirch, France.


The combination of fluorescent genetically encoded proteins with mouse engineering provides a fascinating means to study dynamic biological processes in mammals. At present, green fluorescent protein (GFP) mice were mainly developed to study gene expression patterns or cell morphology and migration. Here we used enhanced GFP (EGFP) to achieve functional imaging of a G protein-coupled receptor (GPCR) in vivo. We created mice where the delta-opioid receptor (DOR) is replaced by an active DOR-EGFP fusion. Confocal imaging revealed detailed receptor neuroanatomy throughout the nervous system of knock-in mice. Real-time imaging in primary neurons allowed dynamic visualization of drug-induced receptor trafficking. In DOR-EGFP animals, drug treatment triggered receptor endocytosis that correlated with the behavioral response. Mice with internalized receptors were insensitive to subsequent agonist administration, providing evidence that receptor sequestration limits drug efficacy in vivo. Direct receptor visualization in mice is a unique approach to receptor biology and drug design.

[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for HighWire Icon for PubMed Central
Loading ...
Support Center