RT Journal Article SR Electronic T1 TMEM120A/TACAN inhibits mechanically activated Piezo2 channels JF bioRxiv FD Cold Spring Harbor Laboratory SP 2021.06.30.450616 DO 10.1101/2021.06.30.450616 A1 John Smith Del Rosario A1 Matthew Gabrielle A1 Yevgen Yudin A1 Tibor Rohacs YR 2021 UL http://biorxiv.org/content/early/2021/06/30/2021.06.30.450616.abstract AB Mechanically activated Piezo2 channels are key mediators of light touch and proprioception in mice and humans. Relatively little is known about what other proteins regulate Piezo2 activity in a cellular context. TACAN (TMEM120A) was proposed to act as a high threshold mechanically activated ion channel in nociceptive dorsal root ganglion (DRG) neurons. Here we find that TACAN co-expression robustly reduced mechanically activated Piezo2 currents, but did not inhibit mechanically activated Piezo1 and TREK1 currents. TACAN co-expression did not affect cell surface expression of either Piezo1 or Piezo2 and did not have major effects on the cortical actin or tubulin cytoskeleton. TACAN expression alone did not result in the appearance of mechanically activated currents above background. In addition, TACAN and Piezo2 expression in DRG neurons overlapped, and siRNA mediated knockdown of TACAN did not decrease the proportion of slowly adapting mechanically activated currents, but resulted in an increased proportion of rapidly adapting currents. Our data do not support TACAN being a mechanically activated ion channel, and identify it as a negative modulator of Piezo2 channel activity.Competing Interest StatementThe authors have declared no competing interest.