Interaction between mitochondria and the actin cytoskeleton in budding yeast requires two integral mitochondrial outer membrane proteins, Mmm1p and Mdm10p.
Interaction between mitochondria and the actin cytoskeleton in budding yeast requires two integral mitochondrial outer membrane proteins, Mmm1p and Mdm10p.
复制标题
DOI：
10.1083/jcb.141.6.1371
复制
发表时间：
1998-06-15
期刊：
影响因子：
--
通讯作者：
Pon LA
中科院分区：
文献类型：
--
作者：
Boldogh I;Vojtov N;Karmon S;Pon LA
在酵母细胞分裂过程中，线粒体转移到子细胞对于存活的后代至关重要。这一过程需要肌动蛋白细胞骨架，可能作为引导线粒体运动到芽中的轨道。沉降测定揭示了线粒体-肌动蛋白相互作用所需的两种不同成分：(1) 线粒体肌动蛋白结合蛋白 (mABP)，一种具有 ATP 敏感肌动蛋白结合活性的外周线粒体外膜蛋白，以及 (2) mABP 与细胞器对接所需的盐不可提取的、可能是完整的膜蛋白。用高盐处理线粒体可消除 mABP 活性。将盐提取的线粒体外周膜蛋白 (SE) 或从 SE 中分离出的具有 ATP 敏感肌动蛋白结合活性的蛋白片段添加到盐洗线粒体中可以恢复这种活性。 mABP对接活性是可饱和的，耐高盐，并且通过用木瓜蛋白酶预处理盐洗线粒体来抑制。两个完整的线粒体外膜蛋白，Mmm1p (Burgess, S.M., M. Delannoy, and R.E. Jensen. 1994. J.Cell Biol. 126:1375–1391) 和 Mdm10p, (Sogo, L.F., and M.P. Yaffe. 1994. J.Cell Biol. 126:1361– 1373）是这些肌动蛋白-线粒体相互作用所必需的。从 mmm1-1 温度敏感突变体或 mdm10 缺失突变体中分离的线粒体没有显示 mABP 活性，也没有 mABP 对接活性。与此一致的是，mmm1-1 和 mdm10Δ 突变体体内的线粒体运动似乎与肌动蛋白无关。使用 latrunculin-A 解聚 F-肌动蛋白会导致长距离线性运动丧失，线粒体运动速度降低五倍。 mmm1-1 和 mdm10Δ 突变体中的线粒体运动与 latrunculin-A 处理的野生型细胞中的线粒体运动没有区别。我们认为 Mmm1p 和 Mdm10p 是 mABP 对接在酵母线粒体表面并将细胞器与肌动蛋白细胞骨架偶联所必需的。
Transfer of mitochondria to daughter cells during yeast cell division is essential for viable progeny. The actin cytoskeleton is required for this process, potentially as a track to direct mitochondrial movement into the bud. Sedimentation assays reveal two different components required for mitochondria–actin interactions: (1) mitochondrial actin binding protein(s) (mABP), a peripheral mitochondrial outer membrane protein(s) with ATP-sensitive actin binding activity, and (2) a salt-inextractable, presumably integral, membrane protein(s) required for docking of mABP on the organelle. mABP activity is abolished by treatment of mitochondria with high salt. Addition of either the salt-extracted mitochondrial peripheral membrane proteins (SE), or a protein fraction with ATP-sensitive actin-binding activity isolated from SE, to salt-washed mitochondria restores this activity. mABP docking activity is saturable, resistant to high salt, and inhibited by pre-treatment of salt-washed mitochondria with papain. Two integral mitochondrial outer membrane proteins, Mmm1p (Burgess, S.M., M. Delannoy, and R.E. Jensen. 1994. J.Cell Biol. 126:1375–1391) and Mdm10p, (Sogo, L.F., and M.P. Yaffe. 1994. J.Cell Biol. 126:1361– 1373) are required for these actin–mitochondria interactions. Mitochondria isolated from an mmm1-1 temperature-sensitive mutant or from an mdm10 deletion mutant show no mABP activity and no mABP docking activity. Consistent with this, mitochondrial motility in vivo in mmm1-1 and mdm10Δ mutants appears to be actin independent. Depolymerization of F-actin using latrunculin-A results in loss of long-distance, linear movement and a fivefold decrease in the velocity of mitochondrial movement. Mitochondrial motility in mmm1-1 and mdm10Δ mutants is indistinguishable from that in latrunculin-A–treated wild-type cells. We propose that Mmm1p and Mdm10p are required for docking of mABP on the surface of yeast mitochondria and coupling the organelle to the actin cytoskeleton.