CELL-SURFACE GLYCOPROTEINS AND PLACE-DEPENDENT SUPPRESSION OF CELL PROLIFERATION

越来越多的证据表明，细胞表面相关糖蛋白具有 在调节参与生长和生长的初级过程中的重要作用 植物和动物的发育。埃德尔曼(1988)创造了这个词 “拓扑生物学”涵盖了依赖于位置的相互作用的范围 由某些与细胞表面相关的糖蛋白介导 与质膜(CAMS)相关或排泄到 细胞外基质(SAM)这些分子已经被牵连到 调节细胞-细胞识别/黏附、细胞分化和细胞 在其他过程中，动物的分裂。我们正在扩展这一概念 包括植物发育的拓扑生物学。尽管肯定会有 是在细胞中运行的调节分子的特定差异 植物和动物的表面，似乎有可能 在真核生物中潜在的类似的发育过程将是 很相似。在这方面，我们已经开始探讨是否有可能 某些糖蛋白，阿拉伯半乳糖蛋白(ACPs)，与 植物细胞表面具有一些类似于凸轮和/或自组装膜的功能 在动物发育方面。我们正将我们的努力集中在依赖于地点的 对细胞增殖的控制，因为它在正常和 植物和动物的异常发育。在植物中，AGP包括 一大家族含有羟脯氨酸的糖蛋白与 质膜和胞外细胞膜都有。我们已经获得了 有证据表明AGPs可能参与抑制植物的细胞分裂。 当我们的“模式”物种之一--膨大裸藻的植物被培养时 在一组条件下，特定叶原基的细胞分裂是 被压制了。当在第二组条件下培养时，细胞分裂 在这些原始体中是“去压抑的”。与经济衰退相关的 细胞分裂是具有浮力的“特定”AGP的消失 密度在1.66到1.64之间。这些AGP是否起到了抑制作用 依赖于位置的细胞分裂抑制？我们将尝试回答 本课题采用CsC1密度梯度和高效液相色谱分离AGP 随着抑制/解除抑制的细胞分裂而改变的分数和 免疫细胞化学方法确定特定的AGP部分是否 与细胞分裂的位置依赖抑制有关。

Evidence is accumulating that cell surface-associated glycoproteins have important roles in regulating primary processes involved in the growth and development of both plants and animals. Edelman (1988) has coined the term "Topobiology" to encompass the range of place-dependent interactions mediated by certain cell surface-associated glycoproteins that are associated with the plasma membrane (CAMs) or excreted into the extracellular matrix (SAMs). These molecules have been implicated in mediating cell-cell recognition/adhesion, cell differentiation, and cell division, among other processes, in animals. We are extending the concept of topobiology to include plant development. Although there are certain to be specific differences in the regulatory molecules operating at the cell surfaces of plants and animals, it seems possible that the mechanisms underlying similar developmental processes in eukaryotic organisms will be similar. In this context, we have begun to explore the possibility that certain glycoproteins, arabinogalactan proteins (ACPs), associated with plant cell surfaces have some functions analogous to the CAMs and/or SAMs in animal development. We are focusing our efforts on the place-dependent control of cell proliferation because of its pivotal role in normal and abnormal development of both plants and animals. In plants, AGPs comprise a large family of hydroxyproline-containing glycoproteins associated with both the plasma membranes and the extracellular matices. We have obtained evidence that AGPs may be involved in suppressing cell division in plants. When plants of one of our "model" species, Gymnocolea inflata, are cultured under one set of conditions, cell division in specific leaf primordia is suppressed. When cultured under a second set of conditions, cell division in these primordia is "desuppressed". Correlated with the desuppression of cell division is the disappearance of "specific" AGPs having buoyant densities between 1.66 and 1.64. Do these AGPs have a role in suppressing a place-dependent suppression of cell division? We will attempt to answer this question by use of CsC1 density gradients and HPLC to isolate AGP fractions that change with suppressed/desuppressed cell division and immunocytochemical procedures to determine if specific AGP moieties are associated with the place-dependent suppression of cell division.