Structural Insights Into D1 Dopamine Receptor Phosphorylation and Desensitization
Dopamine receptors belong to the large G-protein coupled receptor superfamily and molecular cloning studies have revealed the existence of five structurally distinct subtypes (Neve and Neve, 1997). These can be divided into two subgroups on the basis of their amino acid sequences as well as their pharmacological and transductional properties. The first subgroup comprises the D1 and D5 dopamine receptors and is termed “D1-like”. When expressed in mammalian cells, activated D1-like receptors stimulate adenylyl cyclase and raise intracellular levels of cAMP. The second dopamine receptor subgroup includes the D2, D3 and D4 receptors and is termed “D2-like”. The D2-like dopamine receptors are coupled to the inhibition of adenylyl cyclase as well as the modulation of potassium and calcium ion channels. As with other G-protein coupled receptors, dopamine receptors are subject to a wide variety of regulatory mechanisms, which can either positively or negatively modulate their expression and functional activity.
KeywordsDopamine Receptor Okadaic Acid Receptor Phosphorylation Cytoplasmic Loop COOH Terminus
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