The role of β-arrestins in G protein-coupled receptor heterologous desensitization: A brief story.

G protein-coupled receptors (GPCRs) are transmembrane proteins that have an important impact in a myriad of cellular functions. Posttranslational modifications on GPCRs are a key processes that allow these proteins to recruit other intracellular molecules. Among these modifications, phosphorylation is the most important way of desensitization of these receptors. Several research groups have described two different desensitization mechanisms: heterologous and homologous desensitization. The first one involves the phosphorylation of the receptors by protein kinases, such as PKC, following the desensitization and internalization of the receptor, while the second one involves the phosphorylation of the receptors by GRKs, allowing for the receptor to recruit beta-arrestins to be desensitized and internalized. Interestingly, a few number of studies have described the participation of beta-arrestins during the heterologous desensitization process. Hence, the aim of this review is to briefly explore the role that beta-arrestins play during the heterologous desensitization of several GPCRs.