The iDimerize Reverse Dimerization System brings the disruption of protein complexes under real-time, small-molecule control. A protein of interest is fused to the DmrD binding domain, and the fusion protein molecules aggregate unless the D/D Solubilizer ligand is present. Plasmid and lentiviral (Lenti-X) vector formats are available.

Reverse dimerization: Disrupting protein-protein interactions

The iDimerize Reverse Dimerization System is a “reverse dimerization” system—aggregation is the resting state, and the D/D Solubilizer breaks up protein-protein interactions. Therefore, the iDimerize Reverse Dimerization System complements inducible dimerization, and can be used in analogous ways to create inducible alleles. In principle, most processes that can be brought under dimerizer control can also be controlled in the reverse manner using this kit to turn off a process that is activated by oligomerization.

Inducible secretion

The ability to create large protein aggregates has unique applications. For example, adding a secretory signal sequence to fusion proteins allows them to be reversibly stored as aggregates in the endoplasmic reticulum. The ligand can then be added to induce a rapid pulse of protein secretion from the cells. This method has been used to induce rapid, transient, and tightly regulated secretion of human growth hormone (hGH) and insulin (Rivera et al. 2000).

Protein aggregates can also be used in protein trafficking research. For example, this approach has been used to discover the existence of “mega-vesicles” transporting cargo across the Golgi stack (Volchuk et al. 2000).

D/D Solubilizer ligand

The D/D Solubilizer is a synthetic, cell-permeable ligand that can be used to disrupt dimerization of fusion proteins containing the DmrD domain. The D/D Solubilizer has been tested in vitro and in mice. It is nontoxic. We suggest testing various D/D Solubilizer concentrations within the recommended range (10–500 nM) for different lengths of time (30 minutes to 12+ hours) in order to obtain a complete dose-response profile.