Calmodulin-Dependent Regulation of Overexpressed but Not Endogenous TMEM16A Expressed in Airway Epithelial Cells.

ABSTRACT: Regulation of the Ca2+-activated Cl- channel TMEM16A by Ca2+/calmodulin (CAM) is discussed controversially. In the present study, we compared regulation of TMEM16A by Ca2+/calmodulin (holo-CAM), CAM-dependent kinase (CAMKII), and CAM-dependent phosphatase calcineurin in TMEM16A-overexpressing HEK293 cells and TMEM16A expressed endogenously in airway and colonic epithelial cells. The activator of the Ca2+/CAM-regulated K+ channel KCNN4, 1-EBIO, activated TMEM16A in overexpressing cells, but not in cells with endogenous expression of TMEM16A. Evidence is provided that CAM-interaction with TMEM16A modulates the Ca2+ sensitivity of the Cl- channel. Enhanced Ca2+ sensitivity of overexpressed TMEM16A explains its activity at basal (non-elevated) intracellular Ca2+ levels. The present results cor

SUBMITTER: Talbi K 

PROVIDER: S-EPMC8471323 | biostudies-literature | 2021 Sep

REPOSITORIES: biostudies-literature