Mob1 Localization and Function During Mitosis

Mob1 在有丝分裂期间的定位和功能

• 批准号: 8292148
• 负责人: Charles Bradley Shuster
• 金额: $ 24.22万
• 依托单位: NEW MEXICO STATE UNIVERSITY LAS CRUCES
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-08-01 至 2014-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8292148
• 关键词: Actins; Adult; Affect; Anaphase; Aneuploidy; Animals; Architecture; Binding Proteins; Biochemical; Cell Cycle; Cell Cycle Arrest; Cell Cycle Checkpoint; Cell Cycle Proteins; Cell Cycle Regulation; Cell Proliferation; Cell division; Cells; Centromere; Chromosome Segregation; Complex; Cytokinesis; Data; Dependence; Development; Drosophila genus; Elements; Ensure; Eukaryota; Event; Family; Fission Yeast; Foundations; Frequencies; G1/S Transition; Gene Duplication; Gene Family; Genes; Genome; Growth; Homologous Gene; Human; Image; Interphase; Kinetochores; Life; Maintenance; Malignant Neoplasms; Mammalian Cell; Mammals; Mediator of activation protein; Mitosis; Mitotic; Mitotic spindle; Molecular; Molecular Weight; Organ Size; Orthologous Gene; Pathway interactions; Pattern; Phosphorylation; Phosphotransferases; Play; Ploidies; Process; Protein Family; Protein Isoforms; Proteins; RNA Interference; Reporting; Role; Saccharomyces cerevisiae; Saccharomycetales; Signal Transduction; Sister Chromatid; Small Interfering RNA; Testing; Tetraploidy; Tissues; Tumor Suppressor Proteins; Yeasts; aurora B kinase; base; constriction; genetic analysis; insight; loss of function; men; mutant; novel; nuclear division; response; spindle pole body; tumor; tumorigenesis

Maintenance of chromosomal ploidy during cell division requires a precise coordination of chromosome segregation and cytokinesis such that the contractile ring does not assemble before all replicated sister chromatids are correctly attached to the mitotic spindle and the spindle assembly checkpoint is satisfied. In budding and fission yeast, this process is facilitated by a signaling cascade termed the Mitotic Exit Network/Septation Initiation Network that coordinates mitotic exit and cytokinesis, is based at the spindle pole bodies, and plays an active role in initiating constriction of the actin ring. To date, few functional homologues have been characterized in animal cells, but in the case of the terminal components (Mob1 and Dbf2/Sid2), there have been expansions in both gene families. And while tumor suppressor functions have been ascribed to the mammalian and Drosophila orthologs of Mob1 and Dbf2/Sid2 during G1/S, little is known about how these molecules participate in mitosis and cytokinesis in animal cells. Preliminary studies of Mob1 isoforms in cultured human cells indicate that the localization dynamics mirror that observed in yeast, with Mob1 enriched at the kinetochores and spindle poles early in mitosis, and the spindle midzone and midbody during cytokinesis. Moreover, we have determined that Mob1 and the chromosomal passenger complex are mutually dependent on each other kinetochore localization early in mitosis. Lastly, we identified Large Tumor Supressor 2 (Lats2) as a Mob1A-specific binding protein and possible functional homolog of the Dbf2/Sid2 kinase. Using these preliminary studies as a foundation, this application seeks to combine molecular, biochemical and live cell analyses to test the hypothesis that Mob1 proteins perform roles in regulating in maintaining chromosomal ploidy during both mitosis and interphase. The lines of experimentation that form the Specific Aims will: 1) Determine the molecular determinants of Mob1 localization to the kinetochore; 2) Dissect how Mob1 affects Aurora B function at the kinetochore; and 3) Assess the involvement of Mob1 in the Lats2-p53 response to cytoskeletal disruption. These studies will shed novel insights into a gene family that in animal cells appears to act as a negative regulator of cell proliferation (and whose loss of function is associated with tumor formation), yet is essential for completing cell division in yeast. It is anticipated that these studies will help us reconcile how Mob1 is capable of participating in both of these very different but absolutely critical features of cell cycle regulation.

在细胞分裂过程中维持染色体倍性需要精确的染色体配位 隔离和细胞因子，使收缩环在所有复制的姐姐之前都没有组装 染色质正确连接到有丝分裂主轴上，并满足主轴组件检查点。在 萌芽和裂变酵母，该过程由称为有丝分裂出口的信号传导级联 坐标有丝分裂出口和细胞因子的网络/分隔启动网络基于主轴极点 身体，并在启动肌动蛋白环的收缩中起积极作用。迄今为止，功能上很少有 在动物细胞中是特征的，但在末端组件（mob1和dbf2/sid2）的情况下， 在两个基因家族中都是扩张的。尽管肿瘤抑制功能已归因于 G1/S期间，MOB1和DBF2/SID2的哺乳动物和果蝇直系同源 分子参与动物细胞中的有丝分裂和细胞因子。 MOB1同工型在培养的初步研究 人类细胞表明，定位动力学反映了在酵母中观察到的，MOB1富含在 动力学和主轴杆在有丝分裂的早期，以及细胞因子期间的纺锤体中区和中体。 此外，我们已经确定MOB1和染色体乘客络合物相互取决于 在有丝分裂的早期，彼此的动力学定位。最后，我们将大肿瘤supressor 2（LATS2）确定为 MOB1A特异性结合蛋白和DBF2/SID2激酶的可能功能同源物。使用这些初步 作为基础研究，该应用程序旨在将分子，生化和活细胞分析结合起来进行测试 MOB1蛋白在调节两者中保持染色体倍性方面发挥作用的假设 有丝分裂和相间。构成特定目的的实验线将：1）确定 MOB1定位到动力学的分子决定因素； 2）剖析MOB1如何影响极光B 动力学的功能； 3）评估MOB1参与LATS2-P53对 细胞骨架破坏。这些研究将使在动物细胞中出现的基因家族中提供新的见解 充当细胞增殖的负调节剂（其功能丧失与肿瘤有关 形成），但对于完成酵母的细胞分裂至关重要。预计这些研究将帮助我们 调和MOB1如何参与两个截然不同但绝对关键的特征的能力 周期调节。