Alternative mRNA splicing of G protein-coupled receptors.

Alternative mRNA splicing as an important mechanism for generating protein diversity has been implicated to affect 60-70% of human genes (Wang et al., 2008). The G protein-coupled receptors (GPCRs), the largest group of membrane receptors, have a broad distribution and function. Posttranslational modifications or/and association with regulatory proteins can govern cell- and tissue-specific pharmacological, signaling, and regulatory characteristics of GPCRs. However, increasing body of evidence suggests that alternative splicing of GPCRs is a mechanism that can modulate GPCRs' function (Einstein et al., 2008). Many GPCRs have a potential to undergo alternative pre-mRNA splicing (~50%). Due to a general lack of isoform-specific antibodies, GPCRs' alternative splicing is mainly studied on mRNA level employing various PCR techniques. Functional characteristics (including signaling and structure) of alternatively spliced GPCRs are studied in overexpression system employing standard biochemical techniques. In this chapter, we will describe the methods for detection and quantification of alternatively spliced GPCR mRNA. As the experimental paradigm, we use type 1 corticotropin-releasing hormone receptor (CRH-R1).