G protein-coupled receptor kinase 3
In 2003, researchers at the University of California, San Diego published a paper that used gene linkage techniques to identify a mutation in the GRK3 gene as a possible cause of up to 10% of cases of bipolar disorder. This gene is associated with a protein, G protein receptor kinase 3, which appears to be involved in dopamine metabolism, and may provide a possible target for new drugs for bipolar disorder.