Homo- and heteromeric assembly of TRPV channel subunits

• Published in: Journal of cell science Vol. 118; no. 5; pp. 917 - 928
• Main Authors: Hellwig, Nicole, Albrecht, Nadine, Harteneck, Christian, Schultz, Gůnter, Schaefer, Michael
• Format: Journal Article
• Language: English
• Published: England 01.03.2005
• Subjects: Animals; Bacterial Proteins - metabolism; Calcium - chemistry; Calcium Channels - chemistry; Cation Transport Proteins - chemistry; Cell Line; Cell Membrane - metabolism; Cytosol - metabolism; Dimerization; Epithelium - metabolism; Fluorescence Resonance Energy Transfer; Gene Deletion; Green Fluorescent Proteins - metabolism; Hot Temperature; Humans; Immunoblotting; Immunoprecipitation; Ion Channel Gating; Ion Channels - chemistry; Ion Channels - metabolism; Ion Channels - physiology; Luminescent Proteins - metabolism; Mice; Microscopy, Confocal; Microscopy, Video; Models, Biological; Plasmids - metabolism; Protein Binding; Protein Conformation; Protein Structure, Quaternary; Protein Structure, Tertiary; Recombinant Fusion Proteins - chemistry; Transfection; TRPV Cation Channels
• ISSN: 0021-9533; 1477-9137
• DOI: 10.1242/jcs.01675

The vanilloid receptor-related TRP channels (TRPV1-6) mediate thermosensation, pain perception and epithelial Ca²⁺ entry. As the specificity of TRPV channel heteromerization and determinants governing the assembly of TRPV subunits were largely elusive, we investigated the TRPV homo- and heteromultimerization. To analyze the assembly of TRPV subunits in living cells, we generated fluorescent fusion proteins or FLAG-tagged TRPV channel subunits. The interaction between TRPV subunits was assessed by analysis of the subcellular colocalization, fluorescence resonance energy transfer and coimmunoprecipitation. Our results demonstrate that TRPV channel subunits do not combine arbitrarily. With the exception of TRPV5 and TRPV6, TRPV channel subunits preferentially assemble into homomeric complexes. Truncation of TRPV1, expression of cytosolic termini of TRPV1 or TRPV4 and construction of chimeric TRPV channel subunits revealed that the specificity and the affinity of the subunit interaction is synergistically provided by interaction modules located in the transmembrane domains and in the cytosolic termini. The relative contribution of intramolecularly linked interaction modules presumably controls the overall affinity and the specificity of TRPV channel assembly.