Abstract

The cell plasma membrane is a highly dynamic organelle governing a wide range of cellular activities including ion transport, secretion, cell division, growth and development. The fundamental process involved in the addition of new membrane to preexisting plasma membrane however, is unclear. Here we report using biophysical, morphological, biochemical and molecular dynamic simulations, the selective incorporation of proteins and lipids from the cytosol into the cell plasma membrane dictated by membrane stretch and composition. Stretching of the cell membrane as a consequence of volume increase following incubation in a hypotonic solution, results in the incorporation of cytosolic proteins and lipids into the existing plasma membrane. Molecular dynamic simulations further confirm that increased membrane stretch result in the rapid insertion of lipids into the existing plasma membrane. Similarly, depletion of cholesterol from the cell plasma membrane selectively alters the incorporation of lipids into the membrane.