TY - JOUR TI - Secreted CLCA1 modulates TMEM16A to activate Ca2+-dependent chloride currents in human cells AU - Sala-Rabanal, Monica AU - Yurtsever, Zeynep AU - Nichols, Colin G AU - Brett, Tom J A2 - Aldrich, Richard VL - 4 PY - 2015 DA - 2015/03/17 SP - e05875 C1 - eLife 2015;4:e05875 DO - 10.7554/eLife.05875 UR - https://doi.org/10.7554/eLife.05875 AB - Calcium-activated chloride channel regulator 1 (CLCA1) activates calcium-dependent chloride currents; neither the target, nor mechanism, is known. We demonstrate that secreted CLCA1 activates calcium-dependent chloride currents in HEK293T cells in a paracrine fashion, and endogenous TMEM16A/Anoctamin1 conducts the currents. Exposure to exogenous CLCA1 increases cell surface levels of TMEM16A and cellular binding experiments indicate CLCA1 engages TMEM16A on the surface of these cells. Altogether, our data suggest that CLCA1 stabilizes TMEM16A on the cell surface, thus increasing surface expression, which results in increased calcium-dependent chloride currents. Our results identify the first Cl− channel target of the CLCA family of proteins and establish CLCA1 as the first secreted direct modifier of TMEM16A activity, delineating a unique mechanism to increase currents. These results suggest cooperative roles for CLCA and TMEM16 proteins in influencing the physiology of multiple tissues, and the pathology of multiple diseases, including asthma, COPD, cystic fibrosis, and certain cancers. KW - ion channel regulation KW - calcium activated chloride channel KW - chronic inflammatory airway disease JF - eLife SN - 2050-084X PB - eLife Sciences Publications, Ltd ER -