Roles for the APC/C in the centrosome cycle and the centrosomal regulation of the APC/C activity

APC/C 在中心体循环中的作用以及 APC/C 活性的中心体调节

• 批准号: BB/I013938/1
• 负责人: David Glover
• 金额: $ 47.64万
• 依托单位: University of Cambridge
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2011
• 资助国家: 英国
• 起止时间: 2011 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=BB%2FI013938%2F1
• 关键词: Roles; APC; centrosome; cycle; centrosomal

To maintain the correct balance of gene activity from one generation of cells to the next, it is crucial to partition the genetic material during cell division with the high fidelity. The two daughter cells should receive equal number of chromosomes from their mother cell. Chromosomes, which carry all the genetic information, are segregated equally into the two daughter cells by the cellular apparatus named the mitotic spindle. The centrosome is a body located at both ends of the mitotic spindle that focuses the molecular fibres or microtubules that constitute the spindle in most of animal cells. The loss or the over-amplification of centrosomes results in defective mitotic spindles, thereby disastrous cell division that leads to loss of genetic information and potentially facilitates development of diseases such as cancer. In the last decade it has also become clear that the centrosome plays a crucial role in the maintenance of stem cells by organising the specific orientation of the spindle required for constant stem cell renewal. Thus, increased understanding of the molecular mechanisms of centrosome duplication and function will have significant scientific and medical implications. The centrosome comprises two substructures: centrioles and the pericentriolar material (PCM). Centrioles are cylindrical structures, two of which are connected to each other in the centrosome. Centrioles duplicate once every cell division cycle and are inherited into the two daughter cells. Centriole duplication is an evolutionarily conserved process and so can be studied in a model organism, the fruit fly Drosophila melanogaster. In this way our group discovered that the PLK4 is a critical enzyme for controlling the centriole duplication. The PCM contains numerous proteins required to organise microtubules. It accumulates at centrosomes in mitosis in order to form the mitotic spindle. Polo and Aurora A protein kinases are the primal factors that trigger this process by adding phosphate groups onto PCM proteins to change their properties. After cell division the PCM diminishes in size and the centrosome becomes less active. This process that we term 'centrosome regression' remains entirely understudied. In order to ensure the proper inheritance of the genomic information, changes in centrosome structure and function have to be coordinated with the process of cell division. Recently, we and others discovered that in part this involves the ubiquitin-proteasome pathway, a mechanism for destroying proteins when they are no longer needed. A protein complex called the anaphase-promoting complex or cyclosome, (APC/C) specifically targets selected proteins for destruction by pathway and is one of the key regulators of cell division. With this BBSRC grant, we would like to explore how the APC/C participates in coordinating centrosome activity and duplication with the cell division cycle. We will determine exactly which centrosomal proteins interact with the APC/C and will investigate the roles of this interaction in the centrosome cycle. We have found that PLK4 binds to the APC/C, suggesting that the APC/C might regulate the centriole duplication together with a complementary complex of similar function called the SCF. Although it has been long known that the APC/C targets Polo and Aurora A for degradation in the end of cell division, how this is regulated at the centrosome has not been investigated. We have also discovered that a particular PCM protein, Spd-2, strongly binds to a protein called Fizzy-related that regulates the association of the APC/C with its targets. Hence, we would like to understand how these interactions mediate the spatial and temporal control of the destruction of specific proteins to regulate centrosome replication and function.

为了保持基因活性从一代细胞到下一代细胞的正确平衡，在细胞分裂期间以高保真度分配遗传物质至关重要。这两个子细胞应该从母细胞中获得相同数量的染色体。携带所有遗传信息的染色体被称为有丝分裂纺锤体的细胞器均等地分离到两个子细胞中。中心体是位于有丝分裂纺锤体两端的一个体，它聚集了构成大多数动物细胞纺锤体的分子纤维或微管。中心体的丢失或过度扩增导致有丝分裂纺锤体缺陷，从而导致灾难性的细胞分裂，导致遗传信息的丢失，并可能促进疾病如癌症的发展。在过去的十年中，人们也越来越清楚，中心体在维持干细胞中起着至关重要的作用，它组织了干细胞不断更新所需的纺锤体的特定方向。因此，增加对中心体复制和功能的分子机制的理解将具有重要的科学和医学意义。中心体由两个亚结构组成：中心粒和中心粒周围物质（PCM）。中心粒是圆柱形结构，其中两个中心粒在中心体中彼此连接。中心粒在每个细胞分裂周期复制一次，并遗传到两个子细胞中。中心粒复制是一个进化上保守的过程，因此可以在模式生物果蝇中进行研究。通过这种方式，我们的小组发现PLK 4是控制中心粒复制的关键酶。PCM含有组织微管所需的许多蛋白质。在有丝分裂中，它聚集在中心体上以形成有丝分裂纺锤体。波罗和Aurora A蛋白激酶是通过将磷酸基团添加到PCM蛋白上以改变其性质来触发这一过程的主要因素。细胞分裂后，PCM的大小减小，中心体变得不那么活跃。我们称之为“中心体回归”的这个过程仍然完全没有得到充分的研究。为了确保基因组信息的正确继承，中心体结构和功能的变化必须与细胞分裂过程相协调。最近，我们和其他人发现，这部分涉及泛素-蛋白酶体途径，这是一种在不再需要蛋白质时破坏蛋白质的机制。一种称为后期促进复合物或环体的蛋白质复合物（APC/C）特异性靶向选定的蛋白质以通过途径进行破坏，并且是细胞分裂的关键调节因子之一。有了BBSRC的资助，我们想探索APC/C如何参与协调中心体活动和细胞分裂周期的复制。我们将确切地确定哪些中心体蛋白与APC/C相互作用，并将研究这种相互作用在中心体周期中的作用。我们发现PLK 4与APC/C结合，这表明APC/C可能与称为SCF的具有类似功能的互补复合物一起调节中心粒复制。尽管人们早就知道APC/C靶向波罗和Aurora A在细胞分裂结束时降解，但尚未研究其在中心体的调节方式。我们还发现，一种特殊的PCM蛋白Spd-2与一种称为Fizzy-related的蛋白质强烈结合，该蛋白质调节APC/C与其靶点的结合。因此，我们想了解这些相互作用如何介导特定蛋白质破坏的空间和时间控制，以调节中心体复制和功能。

项目成果

Sticky/Citron kinase maintains proper RhoA localization at the cleavage site during cytokinesis.

粘性/香橼激酶在胞质分裂过程中在裂解位点维持正确的 RhoA 定位。

• DOI: 10.17863/cam.57040
• 发表时间: 2011
• 作者: Bassi Z

Targeting of Fzr/Cdh1 for timely activation of the APC/C at the centrosome during mitotic exit.

• DOI: 10.1038/ncomms12607
• 发表时间: 2016-08-25
• 期刊: Nature communications
• 影响因子: 16.6
• 作者: Meghini F;Martins T;Tait X;Fujimitsu K;Yamano H;Glover DM;Kimata Y
• 通讯作者: Kimata Y

DAPPER: a data-mining resource for protein-protein interactions.

• DOI: 10.1186/s13040-015-0063-3
• 发表时间: 2015
• 期刊: BioData mining
• 影响因子: 4.5
• 作者: Haider S;Lipinszki Z;Przewloka MR;Ladak Y;D'Avino PP;Kimata Y;Lio' P;Glover DM
• 通讯作者: Glover DM