Interactions of Dopamine Receptors with G Proteins

Dopamine is an important neurotransmitter, playing roles in motor control, emotion and affect, neuroendocrine regulation, and regulation of sodium uptake in the kidney, among other functions. The receptors for dopamine are members of the superfamily of G protein-coupled receptors (GPCRs). To date, five mammalian dopamine receptors have been cloned ( 1 , 2 )and other subtypes may await discovery. These receptors have been characterized with regard to their pharmacology and modulation of second messengers in a variety of cell types and in vivo. However, less well studied has been the intermediate step between ligand binding and second messenger regulation (i.e., interaction of the receptor with G proteins). This aspect of dopamine receptor function may be quite significant in understanding the actions of dopamine in various tissues or regions of the brain which may contain different complements of receptors and G proteins. In this chapter, we discuss the evidence for which structural features of dopamine receptors are responsible for interaction with G proteins, as well as studies examining interactions of various subtypes of dopamine receptors with specific G proteins. These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.