The regulator of G protein signaling (RGS) domain of G protein-coupled receptor kinase 5 (GRK5) regulates plasma membrane localization and function.

Authors

Hua Xu, Department of Biochemistry and Molecular Biology, Thomas Jefferson UniversityFollow
Xiaoshan Jiang, Department of Biochemistry and Molecular Biology, Thomas Jefferson University; Center for Science Research, Guilin Medical University
Ke Shen, Center for Science Research, Guilin Medical University
Christopher C. Fischer, Department of Biochemistry and Molecular Biology, Thomas Jefferson UniversityFollow
Philip B Wedegaertner, Department of Biochemistry and Molecular Biology, Thomas Jefferson UniversityFollow

Document Type

Article

Publication Date

7-1-2014

Comments

This article has been peer reviewed. It was published in: Molecular Biology of the Cell.
Volume 25, Issue 13, 1 July 2014, Pages 2105-2115.
The published version is available at DOI: 10.1091/mbc.E13-09-0547

Copyright © 2014 Xu, Jiang, et al.

Abstract

The G protein-coupled receptor (GPCR) kinases (GRKs) phosphorylate activated GPCRs at the plasma membrane (PM). Here GRK5/GRK4 chimeras and point mutations in GRK5 identify a short sequence within the regulator of G protein signaling (RGS) domain in GRK5 that is critical for GRK5 PM localization. This region of the RGS domain of GRK5 coincides with a region of GRK6 and GRK1 shown to form a hydrophobic dimeric interface (HDI) in crystal structures. Coimmunoprecipitation (coIP) and acceptor photobleaching fluorescence resonance energy transfer assays show that expressed GRK5 self-associates in cells, whereas GRK5-M165E/F166E (GRK5-EE), containing hydrophilic mutations in the HDI region of the RGS domain, displays greatly decreased coIP interactions. Both forcing dimerization of GRK5-EE, via fusion to leucine zipper motifs, and appending an extra C-terminal membrane-binding region to GRK5-EE (GRK5-EE-CT) recover PM localization. In addition, GRK5-EE displays a decreased ability to inhibit PAR1-induced calcium release compared with GRK5 wild type (wt). In contrast, PM-localized GRK5-EE-CaaX (appending a C-terminal prenylation and polybasic motif from K-ras) or GRK5-EE-CT shows comparable ability to GRK5 wt to inhibit PAR1-induced calcium release. The results suggest a novel model in which GRK5 dimerization is important for its plasma membrane localization and function.

Recommended Citation

Xu, Hua; Jiang, Xiaoshan; Shen, Ke; Fischer, Christopher C.; and Wedegaertner, Philip B, "The regulator of G protein signaling (RGS) domain of G protein-coupled receptor kinase 5 (GRK5) regulates plasma membrane localization and function." (2014). Department of Biochemistry and Molecular Biology Faculty Papers. Paper 80.
https://jdc.jefferson.edu/bmpfp/80

PubMed ID

24807909