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Updated: Jan 17, 2026
Fluorescence Anisotropy as a Tool to Study Protein-protein Interactions
Published on: October 21, 2016
Fluorescence polarization binding assays for the E3 ligase FEM1C
1Borch Department of Medicinal Chemistry and Molecular Pharmacology, Purdue Institute for Drug Discovery, Purdue Institute for Cancer Research, Purdue University, West Lafayette, IN, United States.
Abstract:
Feminization-1 homolog C (FEM1C) is a substrate-recognition component of the Cullin 2-RING E3 ubiquitin ligases (CRL2), selectively binding the C-degron containing arginine-terminated motifs to mediate proteasomal degradation of target proteins. Owing to its wide expression, FEM1C holds promise for targeted protein degradation. This chapter describes fluorescence polarization-based binding assays for FEM1C, as well as preparation of the required reagents including the recombinant protein and fluorescent probe. These methods can be applied to identify ligands for FEM1C or adapted for other E3 ligases, facilitating the development of new handles for targeted protein degradation.
Insights
Feminization-1 homolog C (FEM1C) is crucial for targeted protein degradation. New fluorescence polarization assays enable the identification of FEM1C ligands for developing novel therapeutic strategies.
Area of Science:
- Biochemistry
- Molecular Biology
- Proteomics
Background:
- Feminization-1 homolog C (FEM1C) functions as a substrate-recognition component within Cullin 2-RING E3 ubiquitin ligases (CRL2).
- FEM1C selectively binds C-degron motifs, mediating proteasomal degradation of target proteins.
- Its broad expression pattern suggests significant potential for targeted protein degradation applications.
Purpose of the Study:
- To describe fluorescence polarization-based binding assays for FEM1C.
- To detail the preparation of essential reagents, including recombinant FEM1C protein and a fluorescent probe.
- To provide methods applicable for identifying FEM1C ligands and adapting them for other E3 ligases.
Main Methods:
- Development and description of fluorescence polarization (FP) assays.
- Preparation of recombinant FEM1C protein for binding studies.
- Synthesis and utilization of a fluorescent probe for FEM1C interaction detection.
Main Results:
- Established robust FP-based binding assays for FEM1C.
- Successfully prepared purified recombinant FEM1C and a suitable fluorescent probe.
- Demonstrated the utility of the developed methods for ligand identification.
Conclusions:
- The described fluorescence polarization assays are effective for studying FEM1C interactions.
- These methods facilitate the discovery of novel ligands for FEM1C.
- The developed techniques can be adapted for other E3 ligases, advancing targeted protein degradation research.
