CS-1190

EC50: 1.8±0.13 μM (TRPML3), >29.9 μM (TRPML1)

The conductance of TRPML3 channels is estimate, when activated with 10 µM SN-2 is approximately 10 pS at −80 mV. TRPML3-expressing HEK293 cells are perfused with a series starting with compound alone (in SBS), with compound in ELS, and finally with ELS alone. Two representative compounds, SF-24 and SN-2, are tested. SF-24 is one of the least effective compounds, and SN-2 is one of the most active ones. SN-2 has a similar synergistic effect, also reaching up-to 10-fold enhancement of the combined response when compared with the individual responses, reaching average current densities of up to 3 nA/pF at −80 mV. Dominant negative TRPML3(D458K) is highly effective in eliminating SN-2-induced activity in epidermal melanocytes, suggesting that SN-2 activates a channel that is not responsive in presence of TRPML3(D458K). Such a dominant negative action might be attributed to potential heteromerization of TRPML3(D458K) with an SN-2-responsive channel.