Figure 1.

The protocell concept. (a) Assembly of non-living matter such as lipid vesicles, genomic factors (e.g. DNA/RNA) and other cellular components (e.g. proteins) in a bottom-up approach to build a protocell. (b) Protocells can be varied with respect to the membrane composition to reconstitute different aspects of native cell membranes such as the coexistence of different domains (lipid rafts) or leaflet asymmetry. Moreover, membrane components such as glycoconjugates or transmembrane proteins as well as cytosolic components (e.g. actin filaments) can be incorporated into protocells. (Online version in colour.)