Molecular basis for selective activation of DREADD-based chemogenetics

Area of Science:

• Neuroscience
• Molecular Biology
• Biochemistry

Background:

• Designer receptors exclusively activated by designer drugs (DREADDs) are essential chemogenetic tools for controlling neuronal activity and cellular signaling.
• Muscarinic receptor-based DREADDs, specifically Gq-coupled hM3Dq for excitation and Gi/o-coupled hM4Di for inhibition, are widely used in neuroscience.

Purpose of the Study:

• To determine the high-resolution structures of DREADD complexes bound to their actuators.
• To elucidate the molecular mechanisms underlying DREADD actuator recognition and activation.

Main Methods:

• Cryogenic electron microscopy (cryo-EM) was used to obtain high-resolution structures of DREADD complexes.
• Mutagenesis, functional assays, and computational simulations were employed to complement structural data.

Main Results:

• Four high-resolution cryo-EM structures were determined: hM3Dq-miniGq with deschloroclozapine, hM4Di-miniGo with deschloroclozapine, hM3Dq-miniGq with clozapine-N-oxide, and hM3R-miniGq with iperoxo.
• The structures provide detailed insights into the binding interactions between DREADDs and their specific chemogenetic actuators.
• Analysis revealed the molecular basis for DREADD activation by different ligands.

Conclusions:

• The determined structures offer a molecular understanding of DREADD-chemogenetic actuator interactions.
• These findings will facilitate the rational design and development of next-generation chemogenetic tools for neuroscience research.