Structure-functional intimacies of transient receptor potential channels

Area of Science:

• Biophysics
• Molecular Biology
• Cell Biology

Background:

• Transient receptor potential (TRP) channels are a large superfamily of ion channels, acting as cellular sensors activated by diverse stimuli.
• TRP channels are tetramers with six transmembrane domains and cation-selective pores, often exhibiting high calcium permeability.
• They are classified into seven subfamilies based on sequence homology, including canonical TRPs, vanilloid receptor TRPs, and melastatin TRPs.

Purpose of the Study:

• To review and summarize the current understanding of the structural characteristics of TRP ion channels.
• To highlight key protein domains, structure-function relationships, and insights gained from mutagenesis studies.
• To discuss available crystal structures of TRP channel modules and recent electron microscopy-based structural determinations.

Main Methods:

• Analysis of existing literature on TRP channel structure and function.
• Review of structure-function mutagenesis studies to identify key domains.
• Compilation of data from available crystal structures and electron microscopy studies.

Main Results:

• TRP channels share common structural features like tetrameric assembly, six transmembrane domains, and cation pores.
• Specific protein domains and their roles in channel function are identified through mutagenesis.
• Limited but informative crystal structures of TRP channel modules and recent cryo-EM structures provide atomic-level insights.

Conclusions:

• Understanding TRP channel structure is crucial for elucidating their function as signal integrators.
• Structural data, though incomplete for full channels, reveals important determinants of TRP channel activity.
• Continued structural studies using advanced techniques like electron microscopy are vital for advancing the field.