Dynamics of packaging and division of the yeast mitochondrial nuclei.

酵母线粒体核的包装和分裂动力学。

基本信息

批准号：
16570055
负责人：
MIYAKAWA Isamu
金额：
$ 1.98万
依托单位：
Yamaguchi University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2004
资助国家：
日本
起止时间：
2004 至 2006
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-16570055/
关键词：
yeast mitochondria mitochondrial nuclei mitochondrial nucleoids DNA-binding protein Abf2p

项目摘要

Morphological and biochemical approaches were performed on the mechanisms of packaging and division of yeast mitochondrial nuclei (mt-nuclei).1. Dynamic changes in mt-nuclei during the transition from anaerobic to aerobic culture were investigated in the yeast Saccharomyces cerevisiae. During transition of the culture, the mt-nuclei changes their morphology from giant aggregates to small particles within 6 h. In the present study, we determined DNA content of individual giant mt-nuclei and small mt-nuclei. Next, we found that two species of mt-nuclei proteins were hardly detected in giant mt-nuclei in anaerobically-grown cells, but both proteins appeared in the small mt-nuclei during transfer to aerobic conditions. Using immnofluorescence microscopy, we demonstrated that the dynamic morphological changes in mitochondria occur parallel to the changes of the mt-nuclei and that the actin patches in the cytoplasm also changes from the aggregated forms to the small patches in response to th … More e aerobic conditions.2. Roles of protein components on packaging of the mt-nuclei were investigated, and following results were obtained.We identified a novel mt-nuclei protein named as Mnp1p. This protein was a 22-kDa acidic protein and had a homology with E. coli ribosomal protein, L7/L12. In order to examine the diversity of the mt-nuclei proteins from evolutionary aspects, we isolated the mt-nuclei from the yeast Candida parapsilosis and identified several mt-nuclei proteins. Furthermore, we purified a novel 30-kDa DNA-binding protein, a putative Abf2p homolog. We also successfully purified a 26-kDa Abf2p-like protein from the yeast Pichia jadinii.3. Nuclease sensitivity of the mt-nuclei was compared between mt-nuclei from wild-type cells and Abf2p-deficient cells. We found that the mt-nuclei from Abf2p-deficient cells were more resistant to micrococcal nuclease digestion than the mt-nuclei from wild type cells. During the course of study, we demonstrated that a major nuclease associated with mt-nuclei is a Nuc1p nuclease. MtDNA that is packaged into the mt-nuclei was digested uniformly rather than discontinuously with micrococcal nuclease. Less

对酵母线粒体核（mt-nuclei）的包装和分裂机制进行了形态学和生化研究。1．研究了酿酒酵母从厌氧培养到需氧培养过程中mt-核的动态变化。在培养物中，mt 核在 6 小时内将其形态从巨型聚集体改变为小颗粒。在本研究中，我们测定了单个巨型的 DNA 含量。接下来，我们发现在厌氧生长的细胞的大mt核中几乎检测不到两种mt核蛋白，但在转移到有氧条件期间这两种蛋白都出现在小mt核中。使用免疫荧光显微镜，我们证明线粒体的动态形态变化与线粒体核的变化平行发生，并且细胞质中的肌动蛋白斑块也响应有氧条件从聚集形式转变为小斑块。研究了蛋白质成分对 mt 核包装的作用，并获得了以下结果。我们鉴定了一种新型 mt 核蛋白。该蛋白被命名为Mnp1p，是一种22-kDa的酸性蛋白，与大肠杆菌核糖体蛋白L7/L12具有同源性。从进化角度来看，我们从近平滑假丝酵母中分离了 mt 核，并鉴定了几种 mt 核蛋白。此外，我们还纯化了一种新型 30 kDa DNA 结合蛋白，这是一种推定的 Abf2p 同源物。比较来自酵母 Pichia jadinii 的 26-kDa Abf2p 样蛋白的 mt 核核酸酶敏感性。来自野生型细胞和 Abf2p 缺陷细胞的 mt 核在研究过程中，我们发现来自 Abf2p 缺陷细胞的 mt 核对微球菌核酸酶消化的抵抗力更强。包装到 mt 核中的 MtDNA 被证明与 mt 核相关的主要核酸酶是 Nuc1p 核酸酶。微球菌核酸酶均匀消化而不是不连续消化。