Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI 48824-1319, USA.
J Biochem. 2011 Dec;150(6):627-33. doi: 10.1093/jb/mvr102. Epub 2011 Aug 12.
Human dynamin-like protein 1 (DLP-1) is involved in the fission of mitochondrial outer membranes, a process that helps to maintain mitochondrial morphology and to reduce the accumulation of functional and structural defects in mitochondria. DLP-1 is a ~80 kDa membrane-interacting protein and contains a GTPase domain, a middle domain, a putative PH-like domain and a GTPase effector domain (GED). While the GED has been suggested to be important on protein oligomerization and GTPase activation, functional relationships between the other domains especially the roles of the middle domain in protein activity remains less clear. In this study, we have investigated the biochemical properties of recombinant DLP-1 wild-type and selected mutants, all expressed in Escherichia coli. The middle domain mutants G350D, R365S and ΔPH (lacking the putative PH-like domain) severely impair the GTPase activity, but have no obvious effects on protein tetramerization and liposome-binding properties, suggesting these mutants probably affect protein intra-molecular interactions. Our study also suggested that proper domain-domain interactions are important for DLP-1 GTPase activity.
人源动力蛋白类似物 1（DLP-1）参与线粒体外膜的裂变，这一过程有助于维持线粒体形态，减少线粒体功能和结构缺陷的积累。DLP-1 是一种~80kDa 的膜相互作用蛋白，包含 GTP 酶结构域、中间结构域、假定 PH 结构域和 GTP 酶效应结构域（GED）。虽然 GED 被认为对蛋白质寡聚化和 GTP 酶激活很重要，但其他结构域之间的功能关系，特别是中间结构域在蛋白质活性中的作用仍不明确。在这项研究中，我们研究了重组 DLP-1 野生型和选定突变体的生化特性，所有突变体均在大肠杆菌中表达。中间结构域突变体 G350D、R365S 和ΔPH（缺失假定的 PH 结构域）严重损害 GTP 酶活性，但对蛋白质四聚化和脂质体结合特性没有明显影响，表明这些突变体可能影响蛋白质分子内相互作用。我们的研究还表明，适当的结构域-结构域相互作用对 DLP-1 GTP 酶活性很重要。
