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Updated: Jul 4, 2026
FRET Microscopy for Real-time Monitoring of Signaling Events in Live Cells Using Unimolecular Biosensors
Published on: August 20, 2012
Real-time FRET assay for monitoring detyrosination by TMCP1 and VASH2
Matthieu Simon1, Julien Espeut2, François Juge2
1IBMM, Université Montpellier, CNRS, ENSCM, Montpellier, France.
Abstract:
Tubulin detyrosination is an important α-tubulin specific posttranslational modification which has been implicated in various disorders including neurodegeneration and cancer. As such, the enzymes involved in the generation of this modification emerged as promising therapeutic targets. Previous studies have identified the members of the vasohibin family, VASH1 and VASH2, as the first class of enzymes involved in the generation of detyrosination. Recently, we have discovered Tubulin MetalloCarboxyPeptidase 1 (TMCP1) as the second class of enzymes catalyzing this modification. Here we describe the development of a highly sensitive FRET-based enzymatic assay to study and monitor the activity of TMCP1 and VASH2. The originality of this assay lies in the use of 3-nitrotyrosine as a quencher, which not only restores fluorescence upon cleavage but also closely mimics the natural tyrosine substrate, ensuring optimal enzyme recognition. The selected fluorogenic substrate, named FS2, exhibited strong quenching efficiency and a high signal-to-noise ratio, allowing for real-time kinetic monitoring of TMCP1 and VASH2 activity. Enzyme kinetics, competition assays, and metal ion dependency studies confirmed the assay's specificity, robustness, and physiological relevance. This optimized assay provides a powerful and reliable tool for the future identification and characterization of inhibitors of α-tubulin detyrosination.
Insights
Researchers developed a sensitive FRET assay to measure Tubulin MetalloCarboxyPeptidase 1 (TMCP1) and VASH2 enzyme activity. This tool aids in discovering inhibitors for alpha-tubulin detyrosination, a process linked to cancer and neurodegeneration.
Area of Science:
- Biochemistry
- Molecular Biology
- Enzymology
Background:
- Tubulin detyrosination is a critical posttranslational modification of alpha-tubulin.
- Dysregulation of tubulin detyrosination is linked to neurodegenerative diseases and cancer.
- Vasohibin (VASH) family proteins (VASH1, VASH2) were identified as detyrosination enzymes; Tubulin MetalloCarboxyPeptidase 1 (TMCP1) is a newly discovered class.
Purpose of the Study:
- To develop a sensitive assay for studying the activity of TMCP1 and VASH2.
- To enable real-time kinetic monitoring of alpha-tubulin detyrosination.
- To facilitate the discovery of novel inhibitors targeting these enzymes.
Main Methods:
- Development of a Förster Resonance Energy Transfer (FRET)-based enzymatic assay.
- Utilized 3-nitrotyrosine as a quencher and a fluorogenic substrate (FS2) mimicking natural tyrosine.
- Employed enzyme kinetics, competition assays, and metal ion dependency studies.
Main Results:
- The FRET assay demonstrated high sensitivity, specificity, and robustness.
- The assay effectively monitors TMCP1 and VASH2 activity in real-time.
- 3-nitrotyrosine provided efficient quenching and substrate mimicry, enhancing assay performance.
Conclusions:
- A novel, reliable FRET assay was established for alpha-tubulin detyrosination enzymes TMCP1 and VASH2.
- This assay is a valuable tool for characterizing enzyme kinetics and identifying potential therapeutic inhibitors.
- The findings support targeting alpha-tubulin detyrosination for treating relevant disorders.
