Takahashi Kiyofumi, Otomo Masahiro, Yamaguchi Noboru, Nakashima Hideki, Miyoshi Hiroshi
Department of Neuropsychiatry, St. Marianna University School of Medicine, Kawasaki, Japan.
Biosci Biotechnol Biochem. 2012;76(12):2195-200. doi: 10.1271/bbb.120462. Epub 2012 Dec 7.
Dynamin plays an important role in membrane fission during endocytosis, and its middle domain is involved in the formation of functional oligomers. In this study, we found that replacement of Arg-386 with Gly in the middle domain region of dynamin 1 did not affect the intermolecular interactions of dynamin 1 in the presence of phosphatidylserine-liposomes. But, unexpectedly, this variant showed lower guanosine 5'-triphosphatase activity in the absence of phosphatidylserine-liposomes and enhanced monomer formation from oligomers. Our results indicate that GTPase activity in the absence of lipids is important in the dissociation of oligomer complexes, i.e., reduced basal dynamin 1 GTPase activity is associated with instability of dynamin oligomers.
发动蛋白在胞吞作用期间的膜裂变中发挥重要作用，其中间结构域参与功能性寡聚体的形成。在本研究中，我们发现，在发动蛋白1的中间结构域区域将精氨酸-386替换为甘氨酸，在存在磷脂酰丝氨酸脂质体的情况下并不影响发动蛋白1的分子间相互作用。但是，出乎意料的是，该变体在不存在磷脂酰丝氨酸脂质体时显示出较低的鸟苷5'-三磷酸酶活性，并增强了从寡聚体形成单体的过程。我们的结果表明，在不存在脂质的情况下，GTP酶活性在寡聚体复合物的解离中很重要，即基础发动蛋白1 GTP酶活性降低与发动蛋白寡聚体的不稳定性相关。
