TY - JOUR

T1 - Constitutive internalization across therapeutically targeted GPCRs correlates with constitutive activity

AU - Hendrik Schmidt, Jan

AU - Perslev, Mathias

AU - Bukowski, Lina

AU - Stoklund, Mikkel

AU - Herborg, Freja

AU - Herlo, Rasmus

AU - Lindegaard Madsen, Kenneth

N1 - © 2019 Nordic Association for the Publication of BCPT (former Nordic Pharmacological Society).

PY - 2020

Y1 - 2020

N2 - While the physiological function and mechanisms of agonist-dependent G protein-coupled receptor (GPCR) internalization have been extensively studied, the functional characterization of constitutive internalization of these critically important receptors has received less attention. Here we relate the constitutive internalization of more than 30 therapeutically targeted GPCRs to their agonist-induced internalization. The constitutive internalization ranges from levels of bulk membrane endocytosis in some cases to levels of agonist-induced internalization for other receptors. Moreover, for receptors with high constitutive internalization this occludes further agonist-induced internalization. Additionally, Gq-coupled GPCRs show a significantly higher rate of constitutive internalization than Gs- and Gi-coupled receptors. Finally, we consolidate the proposed link between the constitutive internalization, as assessed by a cytometry-based assay, and the constitutive activity of these receptors, as previously reported by a β-arrestin recruitment assay across the range of pharmacologically relevant receptors. In summary, we provide a quantitative comparison of GPCR internalization across a range of pharmacologically relevant receptors providing generalized insight into the relations between constitutive internalization, constitutive activity and agonist-induced internalization, which has so far relied on mutational studies in individual receptors.

AB - While the physiological function and mechanisms of agonist-dependent G protein-coupled receptor (GPCR) internalization have been extensively studied, the functional characterization of constitutive internalization of these critically important receptors has received less attention. Here we relate the constitutive internalization of more than 30 therapeutically targeted GPCRs to their agonist-induced internalization. The constitutive internalization ranges from levels of bulk membrane endocytosis in some cases to levels of agonist-induced internalization for other receptors. Moreover, for receptors with high constitutive internalization this occludes further agonist-induced internalization. Additionally, Gq-coupled GPCRs show a significantly higher rate of constitutive internalization than Gs- and Gi-coupled receptors. Finally, we consolidate the proposed link between the constitutive internalization, as assessed by a cytometry-based assay, and the constitutive activity of these receptors, as previously reported by a β-arrestin recruitment assay across the range of pharmacologically relevant receptors. In summary, we provide a quantitative comparison of GPCR internalization across a range of pharmacologically relevant receptors providing generalized insight into the relations between constitutive internalization, constitutive activity and agonist-induced internalization, which has so far relied on mutational studies in individual receptors.

U2 - 10.1111/bcpt.13274

DO - 10.1111/bcpt.13274

M3 - Journal article

C2 - 31228220

VL - 126

SP - 116

EP - 121

JO - Basic and Clinical Pharmacology and Toxicology

JF - Basic and Clinical Pharmacology and Toxicology

SN - 1742-7835

IS - S6

ER -