Mechanisms of Initiation of Membrane Fusion: Role of Lipids

Abstract:

Main emphasis in studies on the mechanisms of fusion of cellular membranes has been in the roles of various proteins, with far less interest in the properties of lipids. Yet, on a molecular level fusion involves the merging of lipid bilayers. Studies so far have revealed lipids forming inverted non-lamellar phases to be important in controlling membrane fusion. However, the underlying molecular level mechanisms have remained controversial. While this review is focused on presenting one possible mechanism, involving so-called extended lipid conformation, we are also advocating the view, that in order to obtain a more complete understanding of this process it is necessary to merge the relevant physicochemical properties of lipids with the models describing the specific functions of proteins. To this end, taking into account the central importance of fusion in a wide range of cellular processes, we may anticipate its control to open novel possibilities also for therapeutic intervention.

Keywords: membrane fusion; lipid conformational dynamics; lipid packing; extended lipid conformation; fluorescence spectroscopy; pyrene

Language: English

Document Type: Regular paper

Affiliations: 1: Helsinki Biophysics and Biomembrane Group, Department of Medical Chemistry, Institute of Biomedicine, P.O. Box 8 (Siltavuorenpenger 10A), University of Helsinki, Finland