Dynamic regulation of TASK-1 channels under cellular stress

TASK-1 channel is important for regulating membrane potential. However, its response to pathological conditions remains unknown. In this study, we investigated the effects of hypoxia on the recombinant TASK-1 channel localization at the surface of HEK293T cells. The hypoxic condition was induced via sodium cyanide (NaCN) treatment. Exposure to NaCN led to a significant decrease in TASK-1 levels at the cell surface. This reduction was blocked by pre-exposure to a selective protein kinase C (PKC) inhibitor bisindolylmaleimide. Additional experiments demonstrated that blocking dynamin function or depleting cellular cholesterol prevented TASK-1 from the reduction at the cell surface. Fluorescence microscopic analysis further showed a selective reduction in cell surface wild type TASK-1 under hypoxic conditions, while double-leucine mutant TASK-1 remained unchanged. These results reveal a novel mechanism by which TASK-1 channel localization is modulated by chemical hypoxia, highlighting the importance of PKC, dynamin, and cholesterol in regulating TASK-1 trafficking.