Synthetic protease-activated class B GPCRs.

Synthetic protease-activated class B GPCRs. Biochem Biophys Res Commun. 2020 Sep 10;530(1):246-251 Authors: Willard FS, Meredith TD, Showalter AD, Ma W, Ho JD, Sauder JM, Sloop KW Abstract G-protein coupled receptors (GPCRs) are the ligand detection machinery of a majority of extracellular signaling systems in metazoans. Novel chemical and biological tools to probe the structure-function relationships of GPCRs have impacted both basic and applied GPCR research. To better understand the structure-function of class B GPCRs, we generated receptor-ligand fusion chimeric proteins that can be activated by exogenous enzyme application. As a prototype, fusion proteins of the glucagon-like peptide-1 receptor (GLP-1R) with GLP-1(7-36) and exendin-4(1-39) peptides incorporating enterokinase-cleavable N-termini were generated. These receptors are predicted to generate fusion protein neo-epitopes upon proteolysis with enterokinase that are identical to the N-termini of GLP-1 agonists. This system was validated by measuring enterokinase-dependent GLP-1R mediated cAMP accumulation, and a structure-activity relationship for both linker length and peptide sequence was observed. Moreover, our results show this approach can be used in physiologically relevant cell systems, as GLP-1R-ligand chimeras were shown to induce glucose-dependent insulin secretion in insulinoma cells upon exposure to enterokinase. This approach suggests new strategies for unders...
Source: Biochemical and Biophysical Research communications - Category: Biochemistry Authors: Tags: Biochem Biophys Res Commun Source Type: research