Related Experiment Video
Updated: Jun 28, 2025
Measuring G-protein-coupled Receptor Signaling via Radio-labeled GTP Binding
Published on: June 9, 2017
Quantitative proteomics assay reveals G protein-coupled receptor kinase 4-induced HepG2 cell growth inhibition
Yunxiu Luo1,2, Jing Yang3, Yan Wang4
1Hainan Cancer Hospital, Affiliated Cancer Hospital of Hainan Medical University, Department of Radiotherapy Oncology, Haikou, 570311, China.
Background And Aim:
To investigate the biological effects and putative biological mechanism of G protein-coupled receptor kinase 4 (GRK4) on HepG2 cells.
Materials And Methods:
Cell proliferation, cycle, and apoptosis were evaluated by Cell Counting Kit-8 and flow cytometry (FCM) in HepG2 cells infected with either the GRK4-overexpressing lentivirus vector (OE) or the negative control lentivirus vector (NC). The protein profiles and differentially expressed proteins (DEPs) of the OE and NC cells were analyzed and compared using the quantitative proteomics technique, and their function, expression, and probable mechanism were investigated using bioinformatic assays and parallel reaction monitoring (PRM).
Results:
HepG2 cells that received the OE grew more slowly than those that received the NC. FCM revealed that, when compared to the NC cells, the OE cells had undergone S-phase cycle arrest, and neither the OE nor NC cells underwent apoptosis. Among the 7006 proteins that were identified by quantitative proteomics, 403 DEPs were examined based on the filtering parameters, with the expressions of 135 being downregulated and 268 being upregulated. In addition to being involved in the peroxisome proliferator-activated receptor (PPAR) signaling pathway, the DEPs were implicated in the biological processes of cell proliferation, cycle, and metabolism. PRM verified the expressions of DEPs that were connected to the PPAR pathway.
Conclusions:
This study shows that GRK4 prevents HepG2 cells from proliferating and causes cell cycle arrest in the S-phase, while the PPAR pathway is involved in the regulation of HepG2 cells via GRK4.
Insights
G protein-coupled receptor kinase 4 (GRK4) inhibits HepG2 cell proliferation and induces S-phase cell cycle arrest. The peroxisome proliferator-activated receptor (PPAR) pathway is implicated in GRK4-mediated regulation of these cells.
Area of Science:
- Cell Biology
- Molecular Biology
- Proteomics
Background:
- G protein-coupled receptor kinase 4 (GRK4) is a key regulator of G protein-coupled receptor signaling.
- Understanding GRK4's role in cellular processes is crucial for deciphering its biological effects.
Purpose of the Study:
- To investigate the biological effects of GRK4 on HepG2 cells.
- To elucidate the underlying biological mechanism of GRK4 action.
Main Methods:
- HepG2 cells were infected with GRK4-overexpressing (OE) or negative control (NC) lentivirus vectors.
- Cell proliferation, cell cycle, and apoptosis were assessed using Cell Counting Kit-8 and flow cytometry (FCM).
- Quantitative proteomics and parallel reaction monitoring (PRM) were employed to analyze protein expression profiles and identify differentially expressed proteins (DEPs).
Main Results:
- GRK4 overexpression led to reduced HepG2 cell proliferation and S-phase cell cycle arrest.
- No significant apoptosis was observed in either OE or NC cells.
- Proteomic analysis identified 403 DEPs, with 135 downregulated and 268 upregulated, many involved in the peroxisome proliferator-activated receptor (PPAR) signaling pathway.
Conclusions:
- GRK4 inhibits HepG2 cell proliferation and induces S-phase cell cycle arrest.
- The PPAR signaling pathway plays a role in GRK4-mediated regulation of HepG2 cells.
More Related Videos
Related Concept Videos
01:09GPCRs Regulate Adenylyl Cylase Activity
01:22Amplifying Signals via Enzymatic Cascade