MMM1 encodes a mitochondrial outer membrane protein essential for establishing and maintaining the structure of yeast mitochondria.
MMM1 encodes a mitochondrial outer membrane protein essential for establishing and maintaining the structure of yeast mitochondria.
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DOI：
10.1083/jcb.126.6.1375
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发表时间：
1994-09
期刊：
影响因子：
--
通讯作者：
Jensen RE
中科院分区：
文献类型：
--
作者：
Burgess SM;Delannoy M;Jensen RE
在酿酒酵母中，线粒体是细长的细胞器，其在细胞周边形成网状物。为了确定线粒体形状建立和维持的机制，我们筛选了线粒体形态缺陷的酵母突变体。其中一个突变体mmm1对线粒体的外部形状具有温度敏感性。在限制性温度下，伸长的线粒体似乎迅速塌陷成大的球形细胞器。在恢复到允许温度时，野生型线粒体结构恢复。其他细胞器的形态在mmm1突变体中不受影响，mmm1不破坏正常的肌动蛋白或微管蛋白组织。当在不可发酵的碳源上生长时，MMM 1基因被破坏的细胞是不可存活的，并且在所有温度下都显示出异常的线粒体形态。mmm1突变体的致死性似乎是由于不能将异常形状的线粒体分离成子细胞。因此，线粒体结构对正常细胞功能很重要。Mmm1p位于线粒体外膜，具有面向胞质溶胶的大羧基末端结构域。我们建议，Mmm1p通过将线粒体连接到外部框架（如细胞骨架）来维持线粒体的细长形状。
In the yeast Saccharomyces cerevisiae, mitochondria are elongated organelles which form a reticulum around the cell periphery. To determine the mechanism by which mitochondrial shape is established and maintained, we screened yeast mutants for those defective in mitochondrial morphology. One of these mutants, mmm1, is temperature- sensitive for the external shape of its mitochondria. At the restrictive temperature, elongated mitochondria appear to quickly collapse into large, spherical organelles. Upon return to the permissive temperature, wild-type mitochondrial structure is restored. The morphology of other cellular organelles is not affected in mmm1 mutants, and mmm1 does not disrupt normal actin or tubulin organization. Cells disrupted in the MMM1 gene are inviable when grown on nonfermentable carbon sources and show abnormal mitochondrial morphology at all temperatures. The lethality of mmm1 mutants appears to result from the inability to segregate the aberrant-shaped mitochondria into daughter cells. Mitochondrial structure is therefore important for normal cell function. Mmm1p is located in the mitochondrial outer membrane, with a large carboxyl-terminal domain facing the cytosol. We propose that Mmm1p maintains mitochondria in an elongated shape by attaching the mitochondrion to an external framework, such as the cytoskeleton.