Related Experiment Video
Updated: Jun 8, 2026

Single-molecule Super-resolution Imaging of Phosphatidylinositol 4,5-bisphosphate in the Plasma Membrane with Novel Fluorescent Probes
Published on: October 15, 2016
Visualization of PKA activity in plasma membrane microdomains
Charlene Depry1, Michael D Allen, Jin Zhang
1Department of Pharmacology and Molecular Sciences, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.
Membrane rafts negatively regulate β-adrenergic receptor (β-AR) stimulated Protein Kinase A (PKA) activity. Rafts exhibit higher basal PKA activity, highlighting their role in PKA signaling dynamics within plasma membrane microdomains.
Area of Science:
- Cell Biology
- Biochemistry
- Molecular Biology
Background:
- Membrane rafts are cholesterol-rich microdomains influencing protein signaling.
- The cAMP/Protein Kinase A (PKA) pathway regulates fundamental cellular functions.
- Differential localization of PKA pathway components in membrane rafts is known.
Purpose of the Study:
- To investigate the specific regulation of PKA activity within membrane rafts.
- To examine PKA activity dynamics in distinct plasma membrane microdomains.
- To understand the role of membrane rafts in β-adrenergic receptor (β-AR) stimulated PKA activation.
Main Methods:
- Development of an improved Förster Resonance Energy Transfer (FRET)-based PKA activity biosensor.
- Targeting the biosensor to both membrane raft and non-raft regions of the plasma membrane.
- Cholesterol depletion to disrupt membrane rafts and assess PKA activity.
Main Results:
- Disruption of membrane rafts enhanced β-AR stimulated PKA activity.
- Membrane rafts showed higher basal PKA activity compared to non-raft regions.
- PKA activity in rafts depends on raft integrity and PKA localization.
Conclusions:
- Membrane rafts play a significant role in regulating PKA activity at the plasma membrane.
- Live-cell FRET assays can reveal dynamic differences in plasma membrane microdomains.
- This study provides a foundation for dissecting membrane-regulated signal transduction pathways.
Related Concept Videos
Membrane Domains
Protein Domains
The membrane comprises a group of distinct proteins responsible for carrying out a cell's specific function. For example, the plasma membrane of the human sperm, or a single germ cell, contains a unique set of proteins in the anterior...
Phosphoinositides and PIPs
Different phosphoinositides are synthesized and recruited on the cytosolic face of the plasma membrane. The localization of specific phosphoinositides concentrated in separate membrane...
Enlargement of the Plasma Membrane
Mechanisms of Membrane Domain Formation
Another mechanism for membrane domain formation involves membrane proteins interacting with cytoskeletal...

