Related Experiment Video

Updated: May 3, 2026

A Flow Cytometry-based Assay to Identify Compounds That Disrupt Binding of Fluorescently-labeled CXC Chemokine Ligand 12 to CXC Chemokine Receptor 4
06:56

A Flow Cytometry-based Assay to Identify Compounds That Disrupt Binding of Fluorescently-labeled CXC Chemokine Ligand 12 to CXC Chemokine Receptor 4

Published on: March 10, 2018

13.4K

G Protein-coupled receptor kinase-6 interacts with activator of G protein signaling-3 to regulate CXCR2-mediated

Vandana Singh1, Sandeep K Raghuwanshi, Nikia Smith

  • 1Department of Biology, Julius L. Chambers Biomedical/Biotechnology Research Institute, North Carolina Central University, Durham, NC 27707.

Journal of Immunology (Baltimore, Md. : 1950)
|February 11, 2014
PubMed

Insights

G protein-coupled receptor kinase 6 (GRK6) forms a complex with activator of G protein signaling 3 (AGS3) and Gαi2 to regulate CXCR2 receptor functions, impacting leukocyte recruitment and inflammation.

Area of Science:

  • Cellular and Molecular Biology
  • Immunology
  • Signal Transduction

Background:

  • Interleukin-8 (IL-8, CXCL8) receptors CXCR1 and CXCR2 are crucial for leukocyte recruitment and activation during inflammation.
  • CXCR1 primarily couples with G protein-coupled receptor kinase (GRK)2, while CXCR2 interacts with GRK6.
  • GRKs exhibit diverse protein interactions beyond G protein-coupled receptors.

Purpose of the Study:

  • To identify GRK6 binding partners involved in regulating CXCL8 activities.
  • To investigate the role of GRK6 in CXCR2-mediated cellular responses.

Main Methods:

  • Utilized RBL-2H3 cells expressing CXCR1 or CXCR2, and human/murine neutrophils.
  • Investigated GRK6 interactions with potential binding partners upon CXCR2 activation.
  • Assessed the impact of AGS3 modulation (overexpression and knockdown) on CXCL8-induced cellular responses.

Main Results:

  • Upon CXCR2 activation, GRK6 formed a time-dependent complex with activator of G protein signaling (AGS)3 and Gαi2.
  • AGS3 phosphorylation was induced by CXCR2 activation in a PKC-dependent manner.
  • AGS3 overexpression inhibited CXCL8-induced Ca(2+) mobilization and chemotaxis, while AGS3 inhibition enhanced these responses and receptor recycling.

Conclusions:

  • GRK6 complexes with AGS3-Gαi2 to modulate CXCR2-mediated leukocyte functions.
  • This complex regulates downstream effector activation, receptor trafficking, and cell surface expression.
  • Findings reveal a novel regulatory mechanism for CXCR2 signaling in inflammation.

More Related Videos

A Kinetic Fluorescence-based Ca2+ Mobilization Assay to Identify G Protein-coupled Receptor Agonists, Antagonists, and Allosteric Modulators07:41

A Kinetic Fluorescence-based Ca2+ Mobilization Assay to Identify G Protein-coupled Receptor Agonists, Antagonists, and Allosteric Modulators

Published on: February 20, 2018

8.4K
Measuring G-protein-coupled Receptor Signaling via Radio-labeled GTP Binding10:13

Measuring G-protein-coupled Receptor Signaling via Radio-labeled GTP Binding

Published on: June 9, 2017

15.8K

Related Concept Videos

GPCRs Regulate Adenylyl Cylase Activity01:09

GPCRs Regulate Adenylyl Cylase Activity

Some GPCRs transmit signals through adenylyl cyclase (AC), a transmembrane enzyme. AC helps synthesize second messenger cyclic adenosine monophosphate (cAMP). AC catalyzes cyclization reaction and converts ATP to cAMP by releasing a pyrophosphate. The pyrophosphate is further hydrolyzed to phosphate by the enzyme pyrophosphatase, which drives cAMP synthesis to completion. However, cAMP is rapidly degraded to 5′ AMP by the enzymes phosphodiesterase (PDE), preventing overstimulation of...
6.9K
Interactions Between Signaling Pathways01:19

Interactions Between Signaling Pathways

Signaling cascades usually lack linearity. Multiple pathways interact and regulate one another, allowing cells to integrate and respond to diverse environmental stimuli.
Convergence and divergence, and cross-talk between signaling pathways
Two distinct signaling pathways can converge on a single functional unit, which may either be a single protein or a complex of proteins. The response is either functionally distinct or synergistic between the two pathways but different from the response...
4.7K
Amplifying Signals via Enzymatic Cascade01:22

Amplifying Signals via Enzymatic Cascade

When a ligand binds to a cell-surface receptor, the receptor's intracellular domain changes shape, which may either activate its enzyme function or allow its binding to other molecules. The initial signal is amplified by most signal transduction pathways. This means that a single ligand molecule can activate multiple molecules of a downstream target. Proteins that relay a signal are most commonly phosphorylated at one or more sites, activating or inactivating the protein. Kinases catalyze...
15.3K
G Protein-coupled Receptors01:15

G Protein-coupled Receptors

G Protein-Coupled Receptors or GPCRs are membrane-bound receptors that transiently associate with heterotrimeric G proteins and induce an appropriate response to sensory stimuli such as light, odors, hormones, cytokines, or neurotransmitters.
GPCRs are also called heptahelical, 7TM, or serpentine receptors, and consist of seven (H1-H7) transmembrane alpha-helices that span the bilayer to form a cylindrical core. The transmembrane helices are connected by three extracellular loops and three...
14.1K
G Protein-coupled Receptors01:15

G Protein-coupled Receptors

2.4K
Activation and Inactivation of G Proteins01:22

Activation and Inactivation of G Proteins

Heterotrimeric G proteins are guanine nucleotide-binding proteins. As the name suggests, heterotrimeric G proteins are composed of three subunits: alpha, beta, and gamma. They remain GDP-bound or GTP-bound inside the cells and switch between inactive/active states. The Gα subunit possesses the nucleotide-binding pocket that binds guanine nucleotides and switches between GDP or GTP-bound states. In contrast, the Gꞵ and Gγ subunits are always bound together with high...
8.9K