Hybrid transgenic mice reveal in vivo specificity of G protein-coupled receptor kinases in the heart.

Eckhart, AD

Duncan, SJ

Penn, RB

Benovic, JL

Lefkowitz, RJ

Koch, WJ

United States

2012-10-24T20:55:59Z

2000-01-07

G protein-coupled receptor kinases (GRKs) phosphorylate activated G protein-coupled receptors, including alpha(1B)-adrenergic receptors (ARs), resulting in desensitization. In vivo analysis of GRK substrate selectivity has been limited. Therefore, we generated hybrid transgenic mice with myocardium-targeted overexpression of 1 of 3 GRKs expressed in the heart (GRK2 [commonly known as the beta-AR kinase 1], GRK3, or GRK5) with concomitant cardiac expression of a constitutively activated mutant (CAM) or wild-type alpha(1B)AR. Transgenic mice with cardiac CAMalpha(1B)AR overexpression had enhanced myocardial alpha(1)AR signaling and elevated heart-to-body weight ratios with ventricular atrial natriuretic factor expression denoting myocardial hypertrophy. Transgenic mouse hearts overexpressing only GRK2, GRK3, or GRK5 had no hypertrophy. In hybrid transgenic mice, enhanced in vivo signaling through CAMalpha(1B)ARs, as measured by myocardial diacylglycerol content, was attenuated by concomitant overexpression of GRK3 but not GRK2 or GRK5. CAMalpha(1B)AR-induced hypertrophy and ventricular atrial natriuretic factor expression were significantly attenuated with either concurrent GRK3 or GRK5 overexpression. Similar GRK selectivity was seen in hybrid transgenic mice with wild-type alpha(1B)AR overexpression concurrently with a GRK. GRK2 overexpression was without effect on any in vivo CAM or wild-type alpha(1B)AR cardiac phenotype, which is in contrast to previously reported in vitro findings. Furthermore, endogenous myocardial alpha(1)AR mitogen-activated protein kinase signaling in single-GRK transgenic mice also exhibited selectivity, as GRK3 and GRK5 desensitized in vivo alpha(1)AR mitogen-activated protein kinase responses that were unaffected by GRK2 overexpression. Thus, these results demonstrate that GRKs differentially interact with alpha(1B)ARs in vivo such that GRK3 desensitizes all alpha(1B)AR signaling, whereas GRK5 has partial effects and, most interestingly, GRK2 has no effect on in vivo alpha(1B)AR signaling in the heart.

https://www.ncbi.nlm.nih.gov/pubmed/10625304

0009-7330

https://hdl.handle.net/10161/5938

eng

Ovid Technologies (Wolters Kluwer Health)

Circ Res

Circulation Research

Animals

Atrial Natriuretic Factor

Cardiomegaly

Cell Line

Cyclic AMP-Dependent Protein Kinases

Diglycerides

G-Protein-Coupled Receptor Kinase 3

G-Protein-Coupled Receptor Kinase 5

Gene Expression

Hybridization, Genetic

JNK Mitogen-Activated Protein Kinases

Mice

Mice, Transgenic

Mitogen-Activated Protein Kinases

Mutation

Myocardium

Protein-Serine-Threonine Kinases

RNA, Messenger

Receptors, Adrenergic, alpha

Transgenes

beta-Adrenergic Receptor Kinases

Hybrid transgenic mice reveal in vivo specificity of G protein-coupled receptor kinases in the heart.

Journal article

1

86

https://www.ncbi.nlm.nih.gov/pubmed/10625304

43

50

1

Basic Science Departments

Biochemistry

Chemistry

Clinical Science Departments

Duke

Duke Cancer Institute

Institutes and Centers

Medicine

Medicine, Cardiology

Pathology

School of Medicine

Trinity College of Arts & Sciences

Published

86