Simple model cell is key to understanding cell complexity
The model cell developed in the lab of Christine D. Keating at Penn State uses as the cytoplasm a solution of two different polymers, PEG and dextran (Panel A). The image in Panel B is the image in Panel A highlighted with fluorescent dyes. The blue region is PEG, which is concentrated in the outer polymer solution; the green area is the portion of the membrane that contains PEG groups, which interact with the contents of the cell; and the red area is the portion of the membrane with fewer PEG groups, which interact with the contents of the cell to a lesser extent. After exposure to a concentrated solution of sugar, the cell converted to a budded form (Panel C). A dextran-rich mixture filled the bud, while a PEG-rich mixture remained inside the body of the cell. Panel D shows the image in Panel C highlighted with fluorescent dyes. The blue area is the PEG-rich region. This new structure exhibits polarity both in the membrane and in the aqueous interior of the model cell. A team of Penn State researchers has developed a simple artificial cell with which to investigate the organization and function of two of the most basic cell components: the cell membrane and the cytoplasm--the gelatinous fluid that surrounds the structures in living cells. The work could lead to the creation of new drugs that take advantage of properties of cell organization to prevent the development of diseases. The team's findings will be published later this month (late May 2008) in the Journal of the American Chemical Society.