Membrane fluctuations in erythrocytes are linked to MgATP-dependent dynamic assembly of the membrane skeleton.

The observation of low-frequency fluctuations of the cell membrane in erythrocytes and in several nucleated cells suggests that this phenomenon may be a general property of the living cell. A study of these fluctuations in human erythrocytes and its ghosts has now been carried out using a novel optical method based on point dark field microscopy. We have demonstrated that the reestablishment of membrane fluctuations in erythrocyte ghosts is dependent on MgATP but does not necessarily require the restoration of the biconcave shape. The results imply that the dominant component of membrane fluctuations are metabolically dependent and suggest the existence of a dynamic mechano-chemical coupling within the membrane skeleton network induced by MgATP.