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Updated: Jul 19, 2026

Transmembrane Domain Oligomerization Propensity determined by ToxR Assay
Published on: May 26, 2011
A ToxR-based dominant-negative system to investigate heterotypic transmembrane domain interactions
Eric Lindner1, Dieter Langosch
1Technische Universität München, Lehrstuhl für Chemie der Biopolymere, Weihenstephaner Berg 3,D-85354 Freising-Weihenstephan, Germany.
Abstract:
The ToxR transcription activator system is a genetic tool widely used to examine homotypic interactions of alpha-helical transmembrane domains that drive or support oligomerization of integral membrane proteins. Here, we present a variant of this system that was developed to investigate heterotypic interactions. In this system, a homotypically interacting transmembrane domain within the ToxR protein is coexpressed with a potential competitor that is embedded within an inactivated ToxR mutant. Successful heterotypic interaction competes with homotypic interaction in a dominant-negative fashion as revealed by reduced reporter gene transcription. We expect that this system will be useful for the characterization of transmembrane domains whose homotypic and heterotypic interactions compete with each other.
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