Cigarette smoke impairs the endocytotic process in Saccharomyces cerevisiae

The accumulation of misfolded proteins inside the cells has been considered to be an important contributor to the development of cigarette smoke-mediated diseases. Since endocytosis plays a crucial role in protein trafficking and clearance, impaired endocytosis may contribute to cigarette smoke-mediated protein accumulation. Therefore, the current study investigated the effects of cigarette smoke extract (CSE) on the endocytosis process in the yeast Saccharomyces cerevisiae. The current study demonstrated that treatment of cells with CSE resulted in reduced uptake of the FM4-64 stain, indicating impaired endocytosis. Further analysis revealed that CSE treatment resulted in a defect in the recruitment of proteins involved in endocytosis. Also, aberrant actin filament morphology was found upon CSE treatment, which might interfere with vesicle budding from the membrane. Moreover, the current study showed that the PI(4,5)P2 level in the plasma membrane in CSE-treated cells is reduced due to the failed translocation of MSS4 kinase to the membrane. This reduced PI(4,5)P2 results in aberrant actin filament morphology. Thus, the current study demonstrates that CSE treatment causes endocytosis defects and provides insight into this defective process.