CYTOPLASMIC GELATION AND CELL MOVEMENT IN DICTYOSTELIUM

细胞运动对于基本上所有真核生物的存在都是必不可少的 细胞。这些运动必须涉及产生力量的相互作用 和细胞的结构成分。许多细胞运动的力是 被认为是由肌动蛋白和肌球蛋白产生的，这两种已知的蛋白质 参与肌肉收缩。细胞的结构成分，可能 最近在一些参与细胞运动的细胞中发现了 单元类型。当这些蛋白质与肌动蛋白混合时形成结构凝胶 体外培养。盘基网柄菌具亚基的肌动蛋白结合蛋白 分子量为30,000和95,000道尔顿将在此进行检测 求婚。首先，假设这些组件是 将测试活细胞的运动情况。结合的单抗 将制备并抑制这些结构蛋白的活性 并整合到活细胞中。对这些人的移动的测量 细胞将测试对特定蛋白质的需求。第二， 3万和95000道尔顿的结构和肌动蛋白结合活性 蛋白质将用粘度计、沉淀法和 超微结构技术。第三，三万道尔顿的存在 将评估细胞延伸、伪足和丝状足中的蛋白质 使用生化和免疫化学方法。结果将会是 两者都测试和扩展了我们对细胞分子机制的知识 动静。由于D.的细胞骨架和收缩蛋白。 盘状物与无脊椎动物和脊椎动物细胞中的盘状物同源 类型，对它们的相互作用和细胞内功能的研究可能有 一般意义。细胞运动的全景重要性是 它们在发育生物学、细胞免疫学中的突出地位， 和肿瘤学。了解细胞运动的分子机制将会 指导未来在正常和病理状态下对这些现象的研究， 并最终可能对治疗和诊断的发展做出贡献 程序。

Cell movements are essential to the existence of essentially all eucaryotic cells. These movements must involve the interaction of force generating and structural constituents of cells. The force for many cell movements is thought to be generated by actin and myosin, two proteins known to participate in muscle contraction. Structural components of cells that may participate in cell movements have recently been discovered in a number of cell types. These proteins form structured gels when mixed with actin in vitro. Actin-binding proteins from Dictyostelium discoideum having subunit molecular weights of 30,000 and 95,000 daltons will be examined in this proposal. First, the hypothesis that these components are required for the movement of living cells will be tested. Monoclonal antibodies that bind to and inhibit the activity of these structural proteins will be prepared and incorporated into living cells. Measurements of the movement of those cells will test the requirement for the specific proteins. Second, the structure and actin binding activities of the 30,000 and 95,000 dalton proteins will be examined in detail using viscometry, sedimentation, and ultrastructural techniques. Third, the presence of the 30,000 dalton protein in cellular extensions, pseudopodia and filopodia, will be assessed using both biochemical and immunochemical approaches. The results will both test and extend our knowledge of the molecular mechanisms of cell movements. Since the cytoskeletal and contractile proteins of D. discoideum are homologous to those in both invertebrate and vertebrate cell types, study of their interactions and intracellular functions may have general significance. The panoramic importance of cell movements is verified by their prominence in developmental biology, cellular immunology, and oncology. Knowledge of the molecular mechanisms of cell movements will direct future studies of these phenomena in normal and pathological states, and may eventually contribute to development of therapeutic and diagnostic procedures.