Novel Regulatory Factors of the Spindle Assembly Checkpoint

主轴装配检查点的新颖调节因素

• 批准号: 9210112
• 负责人: Jorge Torres
• 金额: $ 34.65万
• 依托单位: UNIVERSITY OF CALIFORNIA LOS ANGELES
• 依托单位国家: 美国
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-03-01 至 2021-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9210112
• 关键词: Address; Anaphase; Aneuploidy; Antimitotic Agents; Antineoplastic Agents; Apoptotic; Area; Biochemical; Biological; Bypass; Cancer Patient; Cell Cycle; Cell Death; Cell Survival; Cell division; Cells; Chromosomal Instability; Chromosomes; Complement; Complex; Cyclin-Dependent Kinases; Development; Drug resistance; Effectiveness; Ensure; Enzymes; Event; Future; Gene Expression; Genetic; Genetic Materials; Genome Stability; Human; Kinetochores; Lead; Light; Link; Malignant Neoplasms; Maps; Metaphase; Microscopy; Microtubules; Mitosis; Mitotic spindle; Modification; Molecular; Mothers; Outcome; Paclitaxel; Pathway interactions; Pharmaceutical Preparations; Pharmacology; Phosphoric Monoester Hydrolases; Phosphorylation; Play; Poison; Post-Translational Protein Processing; Prometaphase; Protein Dephosphorylation; Proteins; Proteomics; Quality of life; Recruitment Activity; Research; Resistance; Role; Set protein; Sister Chromatid; Small Interfering RNA; Specificity; Tertiary Protein Structure; Testing; Time; anticancer research; base; cancer therapy; daughter cell; improved; interdisciplinary approach; neoplastic cell; novel; protein function; protein protein interaction; public health relevance; repaired; research study; response; transmission process; tumor; tumorigenesis

 DESCRIPTION (provided by applicant): Human cell division is a highly coordinated set of events that ensures the proper transmission of genetic material (chromosomes) from one mother cell to two newly formed cells. Chromosome missegregation during cell division can lead to aneuploidy (an aberrant chromosomal number), which is a hallmark of most cancers and has been proposed to promote tumorigenesis. Critical to ensuring proper sister chromatid separation at the metaphase to anaphase transition is the multi-component spindle assembly checkpoint (SAC), which is activated when unattached kinetochores or nonproductive (monotelic, syntelic, and merotelic) attachments are sensed and functions to arrest cells in metaphase to give time to correct these deficiencies and generate proper microtubule-kinetochore attachments before proceeding with cell division. Interestingly, a functional SAC plays a role in the effectiveness of chemotherapeutic drugs like antimitotics (drugs that inhibit mitosis), which damage the mitotic spindle, activate the SAC, arrest cells in prometaphase and trigger apoptotic cell death. Because understanding the SAC is critical to understanding tumorigenesis and the response of tumor cells to antimitotic drugs, it has become an attractive area of research. Although the last 40 years of research has shed light on the SAC, we are far from elucidating the full complement of regulatory factors involved in this complex pathway and from understanding how misregulation of this pathway can lead to tumorigenesis and resistance to chemotherapeutic drugs like antimitotics. To address these issues, we recently performed a high-throughput small interfering RNA (siRNA) screen for novel regulators of the SAC. This approach yielded two novel cyclin dependent kinases (Cdk14 and Cdk15) and two dual specificity phosphatases (DUSP7 and DUSP12). Inactivation of these novel factors leads to SAC bypass in the presence of antimitotic drugs like Taxol, which normally activate the SAC and induce cell death. To our knowledge, these factors have not been previously linked to SAC functioning and have limited genetic and molecular characterization in general. Thus understanding how these factors regulate the SAC is important to understanding the SAC and more broadly cell division. We hypothesize that these factors are controlling the SAC through their phosphorylation and dephosphorylation activities. Thus, we will test this hypothesis by analyzing the function of these proteins during unperturbed cell divisions and in the presence of antimitotics that generate spindle damage and activate the spindle assembly checkpoint. We expect that our studies will identify and characterize new factors and pathways that regulate the SAC, that we will be able to map their roles in time and space, and that our contributions to understanding the mechanisms of cell division will impact future cancer studies and cancer patient quality of life and survival.

 描述（由申请人提供）：人类细胞分裂是一组高度协调的事件，确保遗传物质（染色体）从一个母细胞正确传递到两个新形成的细胞，细胞分裂过程中染色体错误分离可能导致非整倍性（异常）。染色体数目），这是大多数癌症的标志，并被认为对促进肿瘤发生至关重要，以确保中期到后期转变时正确的姐妹染色单体分离。多组分纺锤体装配检查点 (SAC)，当检测到未附着的着丝粒或非生产性（单粒、合粒和粒粒）附着时，该点被激活，并起到将细胞阻滞在中期的作用，以便有时间纠正这些缺陷并生成适当的微管-着丝粒在有意进行细胞分裂之前，功能性 SAC 在细胞分裂的有效性中发挥着重要作用。 抗有丝分裂药物（抑制有丝分裂的药物）等化疗药物会损害有丝分裂纺锤体，激活 SAC，使细胞停滞在中期并引发细胞凋亡，因为了解 SAC 对于了解肿瘤发生和肿瘤细胞对抗有丝分裂药物的反应至关重要，它已成为一个有吸引力的研究领域，尽管过去 40 年的研究已经揭示了 SAC，但我们还远远没有阐明所涉及的监管因素的全部内容。为了解决这些问题，我们最近对 SAC 的新型调节剂进行了高通量小干扰 RNA (siRNA) 筛选。这种方法产生了两种新型细胞周期蛋白依赖性激酶（Cdk14 和 Cdk15）和两种双特异性磷酸酶（DUSP7 和 DUSP12）。这些新因子在存在抗有丝分裂药物（如紫杉醇）的情况下会导致 SAC 旁路，紫杉醇通常会激活 SAC 并诱导细胞死亡，据我们所知，这些因子以前并未与 SAC 功能相关，并且一般具有有限的遗传和分子特征。因此，了解这些因子如何调节 SAC 对于理解 SAC 和更广泛的细胞分裂非常重要，我们发现这些因子通过其磷酸化和去磷酸化活性来控制 SAC，因此，我们将通过分析这些因子的功能来检验这一假设。 在不受干扰的细胞分裂过程中以及在抗有丝分裂剂存在的情况下，蛋白质会产生纺锤体损伤并激活纺锤体组装检查点，我们希望我们的研究能够识别和表征调节 SAC 的新因子和途径，从而我们能够绘制它们在其中的作用。时间和空间，我们对理解细胞分裂机制的贡献将影响未来的癌症研究和癌症患者的生活质量和生存。