Direct interaction of Cucurbitacin E isolated from Alsomitra macrocarpa to actin filament.
A methanol extract of Alsomitra macrocarpa leaves and branches induced a marked alteration of cell morphology in a human stellate cell line (LX-2). Similar morphologic alterations were observed in several other cell lines. Active compound was purified from the extract and determined to be cucurbitacin E (Cuc E). It has been known that Cuc E causes marked disruption of the actin cytoskeleton, supporting our observation, but how Cuc E altered the actin cytoskeleton has not been elucidated. By using the standard fluorescence assay using copolymerization and depolymerization of native and pyrene labelled actin, this study revealed that Cuc E interacted directly with actin consequently stabilizing the polymerized actin. When NIH-3T3 cells exogenously expressing YFP-labeled actin were treated with Cuc E, firstly the aggregation of globular actin and secondly the aggregation of actin including disrupted fibrous actin in the cells was observed.
Momma
Keiko
K
Graduate School of Biostudies, Kyoto University, Kyoto, 606-8502, Japan.
Masuzawa
Yuko
Y
Nakai
Naomi
N
Chujo
Moeko
M
Murakami
Akira
A
Kioka
Noriyuki
N
Kiyama
Yasunori
Y
Akita
Toru
T
Nagao
Masaya
M