Macroautophagy (hereafter referred to as autophagy) is a catabolic process that regulates important aspects of myocardial metabolism in which cytoplasmic contents including proteins, other macromolecules, and organelles are sequestered in double membrane vesicles and delivered to lysosomes for destruction. While numerous studies have indicated involvement of signaling via Ca2+ in autophagic flux, the precise mechanisms remain unknown. Calmodulin (CaM) is the ubiquitous transducer of intracellular Ca2+ signals. CaM binds to an estimated network of over 300 cellular proteins, yet is expressed insufficiently for its targets. We have begun to examine the role of CaM in autophagic flux in cardiomyocytes. In H9C2 cardiomyocytes, amino acid starvation for 2 hrs triggers autophagic flux, as assessed by the formation of LC3‐II and the decrease in p62 protein levels. Chloroquine dose‐dependently reduces starvation‐induced autophagic flux. Competitive binding assays using purified CaM and FRET‐based CaM biosensors demonstrate direct CaM binding by chloroquine. Consistently, W‐7 and calmidazolium, two other structurally distinct CaM antagonists, dose‐dependently inhibit starvation‐induced formation of autophagic flux. These data demonstrate a role for CaM in autophagic flux in cardiomyocytes.Support or Funding InformationAHA 15SDG25090279 Grant (to E Wauson) and NIH HL112184 grant (to Q‐K Tran)This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.