Cerveny Kara L, Studer Seth L, Jensen Robert E, Sesaki Hiromi
Department of Cell Biology, The Johns Hopkins University School of Medicine, 725 N. Wolfe Street, Baltimore, MD 21205, USA.
Dev Cell. 2007 Mar;12(3):363-75. doi: 10.1016/j.devcel.2007.01.017.
Yeast mitochondrial division requires the dynamin-related Dnm1 protein. By isolating high-copy suppressors of a dominant-negative Dnm1p mutant, we uncovered an unexpected role in mitochondrial division and inheritance for Num1p, a protein previously shown to facilitate nuclear migration. num1 mutants contain an interconnected network of mitochondrial tubules, remarkably similar to cells lacking Dnm1p, and time-lapse microscopy confirms that mitochondrial fission is greatly reduced in num1Delta cells. We also find that Num1p assembles into punctate structures, which often colocalize with mitochondrial-bound Dnm1p particles. Suggesting a role for both Num1p and Dnm1p in mitochondrial inheritance, we find that num1 dnm1 double mutants accumulate mitochondria in daughter buds and that mother cells are frequently devoid of all mitochondria. Thus, our studies have revealed an additional role for Dnm1p in mitochondrial transmission through its interaction with Num1p, thereby providing a link between mitochondrial division and inheritance.
酵母线粒体分裂需要动力蛋白相关的Dnm1蛋白。通过分离显性负性Dnm1p突变体的高拷贝抑制子，我们发现了Num1p在线粒体分裂和遗传中意想不到的作用，Num1p是一种先前显示有助于核迁移的蛋白。num1突变体含有相互连接的线粒体小管网络，与缺乏Dnm1p的细胞非常相似，延时显微镜证实num1Δ细胞中的线粒体分裂大大减少。我们还发现Num1p组装成点状结构，这些结构常常与线粒体结合的Dnm1p颗粒共定位。鉴于Num1p和Dnm1p在线粒体遗传中都起作用，我们发现num1 dnm1双突变体在子芽中积累线粒体，并且母细胞常常没有所有线粒体。因此，我们的研究揭示了Dnm1p通过与Num1p相互作用在线粒体传递中的额外作用，从而在 mitochondrial division和遗传之间建立了联系。 （注：原文中“mitochondrial division”直译为“线粒体分裂”，这里推测可能是“线粒体分配”之类的意思，但按要求未修改）
