Regulation of long-distance dynein motility in the model fungus Ustilago maydis

模型真菌玉米黑粉菌长距离动力蛋白运动的调节

• 批准号: BB/G009872/1
• 负责人: Gero Steinberg
• 金额: $ 45.1万
• 依托单位: UNIVERSITY OF EXETER
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2009
• 资助国家: 英国
• 起止时间: 2009 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=BB%2FG009872%2F1
• 关键词: Regulation; long; distance; dynein; motility

Elongated cells such as neurons in the spine and the brain have to overcome long distances in order to communicate between the periphery and the cell body, which is essential for brain development and learning processes. Long-distance transport is achieved by so-called molecular motors. Fueled by chemical energy they 'walk' their cargo along the fibers of the cytoskeleton, which, much like a railway system, connect all parts of the cell. In the mammalian brain the microtubule cytoskeleton provides the major part of this system, and individual microtubules serve as 'tracks' for the motor proteins kinesin and dynein. Both molecular motors take membranous transport containers (e.g. vesicles) in opposite direction, thereby allowing bi-directional exchange of proteins, membranes and signals. As this fundamental process is essential for cell function and survival, it is not surprising that many neuronal diseases are related to mutations in this transport machinery. The motor dynein moves cargo from the peripheral synapse towards the cell body. In order run over long-distances, dynein needs support of other accessory factors. Among these is the dynactin complex and putative regulators of dynein, such as Lis1 and NudEl. These proteins have also been found to be involved in degenerative neuronal disorders, such as Lissencephaly and Amyotrophic Lateral Sclerosis. Despite much work done on these factors some basic questions, such as their mode of action in membrane trafficking, are still unresolved. Much of our knowledge about the role of e.g. dynactin is restricted to cell-free assays, and some doubt exists whether or not these results can be translated into the living cell. Ideally, one would like to visualize dynein and its regulators during transport of membranous cargo. However, due to technical limitations this was not yet achieved. Filamentous fungi share some striking similarities with human neurons. Their cells, for instance, highly elongated and expand at one cell pole. Transport towards this growing apex is mediated by long-range transport along microtubules, and similar to neurons this process involves dynein, kinesin-1 and kinesin-3. Most of what we know about long-distance transport in fungi was discovered by us using the model fungus Ustilago maydis. This model system shows remarkable similarities to human cells, but it combines powerful technical advantages, including a published genome sequence, numerous genetic tools and many cytological tools such as fluorescent proteins in different colors are established. Very recently we succeeded in visualizing individual dynein motors in membrane trafficking. This technical advancement opens new avenues for addressing the role of dynein and accessory factors in retrograde trafficking. We will make use of these technical advantages in order to address the following questions: (1) How do the dynein accessory factors Lis1, dynactin and NudEl control dynein activity and support long-range motility of individual dynein motors? (2) What is the role of the dynein light chain LC7/roadblock/Km93, which is known to be a tumor suppressor in humans? (3) How dynamic is dynein in elongated cells? (4) What are the factors that take dynein to the loading area at microtubule ends, and that anchor or regulate activities there? The project will provide novel insight into the mechanism of retrograde membrane transport in fungi. It will therefore be of fundamental interest to all aspects of fungal research, but will particularity stimulate research on fungal pathogenicity. Therefore, our work will be of benefit to the UK pharmaceutical and agricultural biotechnology industries. Of even greater potential significance, however, is that the dynein transport machinery is essential for long-distance axonal transport in neurons. Therefore, the proposed studies promise also to provide a better understanding of the role of dynein and accessory factors in motor neuron disorders in mammalian cells.

脊柱和大脑中的神经元等细长细胞必须克服长距离，以便在外周和细胞体之间进行通信，这对大脑发育和学习过程至关重要。长距离运输是通过所谓的分子马达实现的。在化学能的推动下，它们带着货物沿着细胞骨架的纤维“行走”，细胞骨架就像一个铁路系统，连接着细胞的所有部分。在哺乳动物脑中，微管细胞骨架提供了该系统的主要部分，并且单个微管充当马达蛋白驱动蛋白和动力蛋白的“轨道”。这两种分子马达以相反的方向携带膜运输容器（例如囊泡），从而允许蛋白质、膜和信号的双向交换。由于这一基本过程对细胞功能和存活至关重要，因此许多神经元疾病与这种转运机制的突变有关也就不足为奇了。运动动力蛋白将货物从外周突触移向细胞体。为了长距离的运动，动力蛋白需要其他辅助因子的支持。其中包括动力蛋白复合物和动力蛋白的假定调节因子，如Lis 1和NudEl。还发现这些蛋白质参与退行性神经元疾病，如无脑畸形和肌萎缩性侧索硬化症。尽管对这些因素做了大量工作，但一些基本问题，如它们在膜运输中的作用方式，仍然没有得到解决。我们对动力蛋白作用的了解大多局限于无细胞分析，并且对于这些结果是否可以转化为活细胞存在一些疑问。理想情况下，人们希望在膜货物运输过程中可视化动力蛋白及其调节因子。然而，由于技术上的限制，这一目标尚未实现。丝状真菌与人类神经元有一些惊人的相似之处。例如，它们的细胞在一个细胞极高度伸长和扩张。向这个生长顶点的运输是由沿着沿着微管的长程运输介导的，并且与神经元类似，该过程涉及动力蛋白、驱动蛋白-1和驱动蛋白-3。我们所知道的关于真菌中长距离运输的大部分知识都是由我们使用模型真菌玉米黑粉菌发现的。该模型系统显示出与人类细胞的显著相似性，但它结合了强大的技术优势，包括已公布的基因组序列，众多的遗传工具和许多细胞学工具，如不同颜色的荧光蛋白。最近，我们成功地可视化了膜运输中的单个动力蛋白马达。这一技术进步为解决动力蛋白和辅助因子在逆行贩运中的作用开辟了新的途径。我们将利用这些技术优势，以解决以下问题：（1）动力蛋白辅助因子Lis 1，dynactin和NudEl如何控制动力蛋白的活动，并支持单个动力蛋白马达的长距离运动？(2)动力蛋白轻链LC 7/roadblock/Km 93的作用是什么，它是人类已知的肿瘤抑制因子？(3)动力蛋白在细长细胞中的动态如何？(4)是什么因素把动力蛋白带到微管末端的装载区，并在那里锚定或调节活动？该项目将为真菌逆行膜转运机制提供新的见解。因此，它将是真菌研究的各个方面的根本利益，但将特别刺激真菌致病性的研究。因此，我们的工作将有利于英国制药和农业生物技术产业。然而，更重要的潜在意义是动力蛋白运输机制对于神经元中的长距离轴突运输至关重要。因此，拟议的研究也承诺提供一个更好的理解的作用，动力蛋白和辅助因子在哺乳动物细胞运动神经元疾病。

项目成果

Kinesin-3 and dynein cooperate in long-range retrograde endosome motility along a nonuniform microtubule array.

• DOI: 10.1091/mbc.e11-03-0217
• 发表时间: 2011-10
• 期刊: Molecular biology of the cell
• 影响因子: 3.3
• 作者: Schuster M;Kilaru S;Fink G;Collemare J;Roger Y;Steinberg G
• 通讯作者: Steinberg G

Motors in fungal morphogenesis: cooperation versus competition.

真菌形态发生的动力：合作与竞争。

• DOI: 10.1016/j.mib.2011.09.013
• 发表时间: 2011
• 期刊: Current opinion in microbiology
• 影响因子: 5.4
• 作者: Steinberg G

Queueing induced by bidirectional motor motion near the end of a microtubule.

• DOI: 10.1103/physreve.82.051907
• 发表时间: 2010-11
• 期刊: Physical review. E, Statistical, nonlinear, and soft matter physics
• 作者: P. Ashwin;Congping Lin;G. Steinberg

The transport machinery for motility of fungal endosomes.

真菌内体运动的运输机制。

• DOI: 10.1016/j.fgb.2012.01.009
• 发表时间: 2012
• 期刊: FG & B
• 作者: Steinberg G