NOVEL PROBES FOR IMMUNOPHILIN MEDIATED CELL CONTROL

海洋无脊椎动物产生各种各样的天然产品 其中以特定细胞受体为靶标。我们发现， Bastadin-5是海绵Ianthella basa的一种大循环蛋白，是一种 兰诺定敏感的钙通道的强效激动剂 肌浆网(ER502muM)。FKBP12在物理上是一种蛋白质 与影响钙离子转运的兰尼定受体有关 跨越SR/ER。Bastadin-5与FKBP12/ryanodine受体复合体结合 刺激钙离子的释放。钙离子释放的直接调控 FKBP12的细胞内储存及其与钙调神经磷酸酶和钙调神经磷酸酶的结合 转化生长因子-β1受体参与一系列信号转导 导致其他反应的事件，细胞增殖和 差异化。这些都是干预的重要目标 肿瘤发生学。BASTADIN-5结合和结合基序的位置 FKBP12/ryanodine受体复合体是未知的。这个计划是这样的 建议如下：1.新的钙通道的分离和鉴定 黄连提取物中FKBP12/ryanodine受体复合体的调节剂 海洋无脊椎动物。我们将集中讨论的结构 巴斯塔Ianthella basa和Six中额外的巴斯塔素类化合物 不明身份的海洋无脊椎动物样本已经过筛选和 显示出具有很强的钙调节活性。2.确定 所有BASTADINS的定量构效关系(QSAR) 它们激活FKBP/ryanodine受体复合体的能力和 SR/ER制剂中的钙离子外流。这将为以后提供数据 BASTADIN-5与血管内皮细胞相互作用功能模型的建立 FKBP12/ryanodine复合体。3.全合成巴司他丁-5和 BASTADIN-5光亲和标记类似物用于定位 FKBP12/ryanodine复合体上的Bastadin-5效应位点。4.测试 BASTADINS与FKBP12或FKBP12直接相互作用的假说 FKBP12/ryanodine受体复合体上的效应位点影响 兰尼定的功能发生了重大的(前所未有的)变化- 敏感的钙通道。5.要了解调制是如何 Bastadins介导的FKBP12/ryanodine受体复合体对细胞的影响 以BC3H1细胞系为模型进行生长分化实验。

Marine invertebrates produce a diverse array of natural products some of which target specific cellular receptors. We have found that bastadin-5, a macrocycle from the marine sponge Ianthella basta is a potent agonist of the ryanodine-sensitive Ca2+ channel of the sarcoplasmic reticulum, SR (ER502muM). FKBP12 is a protein physically associated with the ryanodine receptor that affects Ca2+ transport across SR/ER. Bastadin-5 binds to FKBP12/ryanodine receptor complex and stimulates release of Ca2+. Direct modulation of Ca2+ release from intracellular stores by FKBP12 and binding of FKBP12 to calcineurin and the TGF-beta1 receptor are involved in a cascade of signal transduction events that lead to among other responses, cell proliferation and differentiation. These are important targets for intervention in tumorigenesis. The locus of binding and binding motif of bastadin-5 to the FKBP12/ryanodine receptor complex are unknown. The plan of this proposal is, 1. Isolation and characterization of new Ca2+ channel modulators of the FKBP12/ryanodine receptor complex from extracts of marine invertebrates. We will concentrate on the structures of additional bastadin-like compounds in Ianthella basta and six unidentified marine invertebrate samples which have been screened and shown to contain potent Ca2+ modulatory activity. 2. Determine the quantitative structure-activity relationships (QSAR) for all bastadins for their ability to activate the FKBP/ryanodine receptor complex and Ca2+ efflux from SR/ER preparations. This will provide data for later development of a functional model for bastadin-5 interaction with the FKBP12/ryanodine complex. 3. Total synthesis of bastadin-5 and bastadin-5 photoaffinity-labelled analogs for use in localization of the bastadin-5 effector site on FKBP12/ryanodine complex. 4. Test the hypothesis that bastadins interact directly with FKBP12 or the FKBP12 effector site on the FKBP12/ryanodine receptor complex to affect a significant (unprecedented) change in the function of ryanodine- sensitive Ca2+ channels. 5. To understand how modulation of the FKBP12/ryanodine receptor complex by bastadins influences cellular growth and differentiation using the BC3H1 cell line as model.