Evidence for the activity of a phospholipid exchange protein in vivo

Liposomes containing a self quenching concentration of a fluorescent phosphatidylethanolamine analog, were microinjected into Chinese hamster ovary cells. Immediately after microinjection, little intracellular fluorescence was observed. 10 min post-injection, labeling of the nuclear envelope and mitochondria became evident. Combined with control studies, our results suggest that phospholipid exchange protein(s) facilitates phosphatidylethanolamine movement in vivo.