Figure 6.

Cellular metabolic energy promotes internalization of Opa₆₀ proteoliposomes into HeLa cells. Control, CEACAM1, and CEACAM3 HeLa cells were treated with metabolic inhibitors (black) in order to deplete available cellular ATP compared to untreated cells (white). Following treatment, cells were exposed to 0.2 mM [phospholipid] Opa₆₀ proteoliposomes for one hour before being washed, lifted, and fixed in 4% PFA. Depletion of cellular ATP inhibits internalization of Opa₆₀ proteoliposomes into cells, with ATP depletion strongly inhibiting liposome uptake into HeLa cells expressing CEACAM1 or CEACAM3. A smaller effect was seen on internalization into control cells, which could be due to non-active uptake processes present in these cells. Error bars represent 95% C.I.