Fission, fusion and distribution of mitochondria in mammalian cells

线粒体是小的细胞隔室，以ATP的形式产生细胞的大部分能量。线粒体曾经被认为是漂浮在细胞中的豆状细胞器，但现在很清楚情况并非如此。线粒体被发现是一个从细胞核周围辐射的小管网络，它们通过裂变和融合事件不断改变其形状。线粒体沿着微管运输，微管在细胞中充当高速公路，使得它们可以分布到需要ATP或线粒体特有的其他功能（例如它们调节钙释放的能力）的区域。在专门的细胞中，线粒体组织得更进一步。精子细胞中含有线粒体，线粒体包裹在鞭毛的中段，这样ATP就可以直接用于游泳。线粒体在肌肉细胞中也是高度组织化的，为运动提供ATP，而在胰腺细胞中，细胞边缘的线粒体有助于调节胰岛素等分子分泌到血液中。虽然我们开始了解线粒体对细胞的重要性，但我们还没有弄清楚这些细胞器如何经历对细胞功能至关重要的剧烈形态变化。在这个应用中，我们计划识别和鉴定参与线粒体分裂和这些细胞器沿着微管高速公路运动的蛋白质。了解组织培养细胞中线粒体动力学的基本机制将为分化细胞（如精子、神经、肌肉和胰腺细胞）中的线粒体分离和专门化提供有价值的见解，这些事件对功能至关重要。

Mitochondria are small cellular compartments that produce most of the cell's energy in the form of ATP. Mitochondria were once thought of as small bean-shaped organelles floating around in the cell, however it has become clear that this is not the case. Mitochondria are found as a network of tubules radiating from around the nucleus and they undergo constant changes in their shape through both fission and fusion events. Mitochondria are transported along microtubules which act as highways in the cell so that they can be distributed to areas that require ATP or other functions particular to mitochondria such as their ability to regulate the release of calcium. In specialist cells, mitochondria are organised even further. Sperm cells contain mitochondria packed around the mid-piece of the flagellum so that ATP can be utilised directly for swimming. Mitochondria are also highly organised in muscle cells to supply ATP for movement while in pancreatic cells mitochondria at the cell's edge help to regulate the secretion of molecules such as insulin into the bloodstream. While we are beginning to understand the great importance of mitochondria to the cell, we are yet to work out how these organelles undergo the drastic morphological changes which are essential for cellular function. In this application, we plan to identify and characterise the proteins involved in the division of mitochodria and the movement of these organelles along the microtubule highways. Understanding the basic mechanisms of mitochondrial dynamics in tissue culture cells will provide valuable insights into mitochondrial segregation and specialisation in differentiated cells such as sperm, nerve, muscle and pancreatic cells, where such events are crucial for function.