Activation of dynamin II by POPC in giant unilamellar vesicles: a two-photon fluorescence microscopy study.

LUIS A. BAGATOLLI; D.D. BINNS; D.M. JAMESON; J. ALBANESI

JOURNAL OF PROTEIN CHEMISTRY

Plenum Publishing Corporation

Año: 2002 vol. 21 p. 383 - 383

0277-8033

he interaction of dynamin II with giant unilamellar vesicles was studied using two-photon fluorescence microscopy. Dynamin II, labeled with fluorescein, was injected into a microscope chamber containing giant unilamellar vesicles, which were composed of either pure 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) or a mixture of POPC and phosphatidylinositol 4,5-bisphosphate (PI(4,5)P2). Binding of the fluorescent dynamin II to giant unilamellar vesicles, in the presence and absence of PI(4,5)P2, was directly observed using two-photon fluorescence microscopy. This binding was also visualized using the fluorescent N-methylanthraniloyl guanosine 5´-[gamma-thio]triphosphate analogue. The membrane probe 6-dodecanoyl-2-dimethylamine-naphthalene was used to monitor the physical state of the lipid in the giant unilamellar vesicles in the absence and presence of dynamin. A surprising finding was the fact that dynamin II bound to vesicles in the absence of PI(4,5)P2. Activation of the G