Related Experiment Video
Updated: Jan 31, 2026
Mimicking the Function of Signaling Proteins: Toward Artificial Signal Transduction Therapy
Published on: September 29, 2016
Characterization of the epithelial membrane protein 3 interaction network reveals a potential functional link to
Arne Christians1, Eric Poisel2,3, Christian Hartmann1
1Department of Neuropathology, Institute of Pathology, Hannover Medical School, Hannover, Germany.
Abstract:
Epithelial Membrane Protein 3 (EMP3), a 4-transmembrane glycoprotein, first gained attention as a putative tumor suppressor. Accumulating evidence, however, points to a more tumor promotive function of EMP3. The biological function of EMP3 remains largely unclear. To elucidate more of EMP3's interaction network, we performed a Yeast-Two-Hybrid (Y2H) screening, followed by validation of candidate interactors by Biomolecular Fluorescence Complementation (BiFC) and Proximity Ligation Assay (PLA). Furthermore, we generated stable EMP3 knockdown cell lines and measured cell proliferation, migration and sensitivity to apoptosis induction as well as the expression and activation levels of important signal pathway components. The Y2H screening yielded 10 novel interactions of EMP3, eight of which could also be detected by BiFC and PLA interaction assays. All newly discovered interaction partners are involved in signaling or trafficking regulation. Most notably, FLOT1 and HTATIP2 have well described roles in the regulation of EGFR signaling. In addition, knockdown of EMP3 resulted in reduced levels of p-AKT, p-ERK and p-EGFR, attenuated cell proliferation and migration and sensitized cells to apoptosis induction by TRAIL and Staurosporine. Based on these observations we hypothesize that EMP3 might be involved in the regulation of receptor-tyrosine-kinase mediated mitogenic signaling.
Insights
Epithelial Membrane Protein 3 (EMP3) interacts with signaling proteins, influencing cell growth and survival. Knockdown of EMP3 reduces proliferation and migration, suggesting a role in cancer signaling pathways.
Area of Science:
- Molecular Biology
- Cell Biology
- Cancer Research
Background:
- Epithelial Membrane Protein 3 (EMP3) is a 4-transmembrane glycoprotein with a debated role in tumorigenesis, initially considered a tumor suppressor but now increasingly implicated in tumor promotion.
- The precise biological functions and interaction network of EMP3 are not well understood, necessitating further investigation into its cellular roles.
Purpose of the Study:
- To identify novel interaction partners of EMP3 and elucidate its functional network.
- To investigate the impact of EMP3 on cellular processes such as proliferation, migration, and apoptosis.
- To explore EMP3's potential involvement in receptor-tyrosine-kinase signaling pathways.
Main Methods:
- Yeast-Two-Hybrid (Y2H) screening was employed to identify potential EMP3 interacting proteins.
- Biomolecular Fluorescence Complementation (BiFC) and Proximity Ligation Assay (PLA) were used to validate Y2H findings.
- Stable EMP3 knockdown cell lines were generated to assess functional consequences, including proliferation, migration, apoptosis sensitivity, and signaling pathway activation.
Main Results:
- Ten novel interaction partners of EMP3 were identified via Y2H screening, with eight confirmed by BiFC and PLA assays.
- Validated interactors are primarily involved in cellular signaling and trafficking regulation, notably FLOT1 and HTATIP2, known regulators of EGFR signaling.
- EMP3 knockdown led to decreased levels of phosphorylated AKT, ERK, and EGFR, reduced cell proliferation and migration, and increased sensitivity to apoptosis induction.
Conclusions:
- EMP3 interacts with multiple proteins involved in signaling and trafficking.
- EMP3 plays a role in promoting cell proliferation and migration, potentially through the regulation of EGFR signaling.
- EMP3 may be involved in receptor-tyrosine-kinase-mediated mitogenic signaling, highlighting its potential as a therapeutic target in cancer.
Related Concept Videos
02:04Covalently Linked Protein Regulators
These groups modify specific amino acids in a protein....
02:04Covalently Linked Protein Regulators
02:26Protein Networks
These interactions can be represented through maps depicting protein-protein interaction networks, represented as nodes and edges. Nodes are circles that are representative of a protein,...
02:26Protein Networks
01:16Introduction to Membrane Proteins
01:21The Resting Membrane Potential