ABSTRACT
TMEM16F, a Ca2+-activated lipid scramblase (CaPLSase) that dynamically disrupts lipid asymmetry, plays a crucial role in various physiological and pathological processes such as blood coagulation, neurodegeneration, cell-cell fusion, and viral infection. However, the mechanisms through which it regulates these processes remain largely elusive. Using endothelial cell-mediated angiogenesis as a model, here we report a previously unknown intracellular signaling function of TMEM16F. We demonstrate that TMEM16F deficiency impairs developmental retinal angiogenesis in mice and disrupts angiogenic processes in vitro. Biochemical analyses indicate that the absence of TMEM16F enhances the plasma membrane association of activated Src kinase. This in turn increases VE-cadherin phosphorylation and downregulation, accompanied by suppressed angiogenesis. Our findings not only highlight TMEM16F's intracellular signaling role in endothelial cells but also open new avenues for exploring the regulatory mechanisms of membrane lipid asymmetry and their implications in disease pathogenesis.
