Structure of human TRPV4 in complex with GTPase RhoA

Area of Science:

• Molecular and Cellular Biology
• Structural Biology
• Pharmacology

Background:

• Transient receptor potential (TRP) channel TRPV4 is a key cellular sensor involved in numerous physiological processes.
• Dysfunction of TRPV4 is linked to various diseases, including neuromuscular disorders, edema, and cancer, making it a significant drug target.
• The GTPase RhoA is known to modulate TRPV4 activity, but the structural basis of this interaction was unclear.

Purpose of the Study:

• To elucidate the structural basis of the interaction between human TRPV4 (hTRPV4) and RhoA.
• To identify the binding sites and mechanisms of action for TRPV4 agonists and inhibitors.
• To provide insights into disease pathogenesis related to TRPV4 mutations and guide therapeutic development.

Main Methods:

• Determined the cryo-electron microscopy structure of the human TRPV4-RhoA complex.
• Analyzed the molecular interface between TRPV4 and RhoA, identifying key residues.
• Mapped the binding sites for the TRPV4 agonist 4α-PDD and inhibitor HC-067047.

Main Results:

• The structure reveals RhoA binding to the membrane-proximal ankyrin repeat domains of TRPV4.
• Specific residues at the TRPV4-RhoA interface are implicated in neuropathy-causing mutations.
• Agonist binding at the S1-S4 domain base promotes channel opening, while inhibitor binding induces a conformational change in the S6 helix.

Conclusions:

• The study provides a detailed structural understanding of hTRPV4 regulation by RhoA.
• The findings illuminate the molecular basis of TRPV4-related diseases and drug interactions.
• These structures serve as a foundation for designing novel therapeutics targeting TRPV4.