Cytoplasmic inter-subunit interface modulates TRPC5 activity: Molecular mechanism behind intellectual...

Area of Science:

• Molecular biology
• Neuroscience
• Biophysics

Background:

• Transient Receptor Potential Canonical 5 (TRPC5) channels are vital in the brain, kidney, and sensory neurons.
• TRPC5 dysfunction is linked to neurodevelopmental disorders, with the R175C mutation associated with intellectual disability and autism.
• The precise gating mechanisms of TRPC5 remain poorly understood, hindering therapeutic development.

Purpose of the Study:

• To elucidate the molecular mechanisms of TRPC5 channel gating.
• To understand how the R175C mutation impairs TRPC5 function.
• To investigate the role of the 'zero-tolerance' region in TRPC5 gating.

Main Methods:

• Structural analysis and bioinformatics profiling.
• Molecular simulations.
• Site-directed mutagenesis and electrophysiological recordings.

Main Results:

• The R175 residue is part of a critical inter-subunit interface regulating TRPC5 gating.
• A conserved 'zero-tolerance' region mediates hydrogen bonding dynamics at the interface.
• Conformational changes (closed vs. open) correlate with distinct contact patterns within the zero-tolerance region.
• TRPC5 activity is modulated by post-translational modifications at this interface, such as phosphorylation at S193.

Conclusions:

• The study characterizes the molecular basis of R175C-induced TRPC5 dysfunction.
• The 'zero-tolerance' region plays a key role in TRPC5 channel gating and regulation.
• Findings provide insights into TRPC5 channel function relevant to neurodevelopmental disorders.