Intermediate filaments and lipoprotein cholesterol.

The ability of cells to utilize cholesterol derived from lipoprotein is important in plasma membrane biosynthesis, steroidogenesis and the regulation of sterol synthesis. While the endocytosis of lipoprotein-derived cholesterol has been well characterized, the subsequent events that mediate its post-lysosomal intracellular transport are not understood. Recent studies have suggested that vimentin-type intermediate filaments may have a role in cholesterol transport. The mechanism by which vimentin filaments affect this process is not known, but future studies promise to provide new insights into both the post-lysosomal transport of cholesterol and the intracellular functions of intermediate filaments.