Structural domains required for channel function of the mouse transient receptor potential protein homologue TRP1β

Transient receptor potential proteins (TRP) are supposed to participate in the formation of store-operated Ca²⁺ influx channels by co-assembly. However, little is known which domains facilitate the interaction of subunits. Contribution of the N-terminal coiled-coil domain and ankyrin-like repeats and the putative pore region of the mouse TRP1β (mTRP1β) variant to the formation of functional cation channels were analyzed following overexpression in HEK293 (human embryonic kidney) cells. MTRP1β expressing cells exhibited enhanced Ca²⁺ influx and enhanced whole-cell membrane currents compared to mTRP1β deletion mutants. Using a yeast two-hybrid assay only the coiled-coil domain facilitated homodimerization of the N-terminus. These results suggest that the N-terminus of mTRP1β is required for structural organization thus forming functional channels. [Copyright &y& Elsevier]