Expression of the G protein-coupled receptor kinase 2 during early mouse embryogenesis.

Whilst several G protein-coupled receptors (GPCRs) have been shown to play important roles during development, little study has been carried out on the G protein-coupled receptor kinases (GRKs) that modulate their activity in embryos. Here, we have analyzed the expression of GRK2, the predominant GRK expressed during embryogenesis. We show that at early stages, the expression of GRK2 is restricted to populations of cells that are undifferentiated, multipotent and in many cases, migratory. As such, GRK2 transcripts were found in the early mesoderm and neural crest as they migrate from the primitive streak and the neural tube, respectively. In the limb bud, GRK2 transcripts were observed in cells of the progress zone and in the interdigital areas. At later stages, the expression in the heart is compatible with the phenotype observed in the GRK2 deficient mice.