PostDoctoral Research Fellowship In Plant Biology

参与有丝分裂运动的机制是我们细胞生物学知识的核心，但仍然知之甚少。了解这些机制的调控对于建立细胞分裂和细胞运动的综合模型至关重要。最近已经开发了一个模型系统，其中可以使用硅藻中分离的功能纺锤体在体外研究后期B（纺锤体伸长）。利用该系统，我们发现纺锤体在体外的伸长需要一个高度磷酸化的环境。与微管重叠区相关的几个磷酸化蛋白也被鉴定出来。因此，蛋白磷酸化可能在有丝分裂的调控中起关键作用。提出了所涉及的蛋白激酶的鉴定和表征。将开发一种体外定量分析，从而可以评估重叠区蛋白的磷酸化水平。磷酸化的重叠区蛋白可能是纺锤体运动功能的组成部分。还提出了对这些蛋白质的免疫分析。将建立针对磷酸化重叠区蛋白的单克隆抗体库。发现任何抑制B后期的抗体将用于纯化抗原以进行体外鉴定。抗体也将在高等植物细胞上进行试验，看看这些蛋白质是否与高等植物有丝分裂机制相同。有丝分裂是真核细胞遗传的核心。了解与染色体有序运动有关的分子机制对于理解细胞分裂的机制以及遗传信息的传递至关重要。这项研究的结果将大大提高我们目前的最低限度的了解。

The mechanisms involved in mitotic movements are central to our knowledge of cell biology yet remain poorly understood. Understanding the regulation of these mechanisms is crucial to development of an integrated model of cell division and cellular motility in general. Recently a model system has been developed where anaphase B (spindle elongation) can be studied in vitro using isolated, functional spindles from a diatom. Using this system it was found that spindle elongation in vitro requires a highly phosphorylated environment. Several phosphorylated proteins associated with the microtubule overlap zone were also identified. Protein phosphorylation thus may play a key role in the regulation of mitosis. The identification and characterization of the protein kinase(s) involved is proposed. An in vitro quantitative assay will be developed whereby phosphorylation levels of overlap zone proteins can be evaluated. Phosphorylated overlap zone proteins may be integral to spindle motor function. Also proposed is an immuno-analysis of these proteins. A monoclonal antibody library will be raised against phosphorylated overlap zone proteins. Any antibodies found to inhibit anaphase B will be used to purify the antigen for in vitro characterization. Antibodies also will be tried on higher plant cells to see if these proteins are common to the higher plant mitotic machinery as well. Mitosis is central to genetic inheritance in eukaryotic cells. Knowledge of the molecular mechanisms involved with the ordered movement of chomosomes is essential to any understanding of the mechanics of cell division as well as the transmission of genetic information. The results of this study should greatly enhance the minimal understanding we now have.