CA2+-Mediated Signal Transduction in Plants

最近发现了一个新的 Ca2 依赖性蛋白激酶家族，称为 CDPK。 CDPK 是独特的，因为它们具有新颖的结构，其中激酶结构域连接到与钙调蛋白类似的 Ca2 结合结构域。 一个重要的长期目标是了解 CDPK 在 Ca2 介导的信号转导途径中的功能。 为此选择了模型植物系统拟南芥。 该提案的基础是确定 Ca2 如何调节 CDPK 活性。 将使用生化和分子遗传学方法来测试称为“CaMK II 流线型版本”的模型。 大肠杆菌。表达系统已被开发来提供用于此目的的功能酶。 将采用两种方法来研究特定 CDPK 同工型的生物学功能：1) 同工型 AK1 和 AK1 的突变“不受调控”版本将在转基因植物中过表达，以检查改变其体内活性平衡的影响。 2) 将确定 AK1 的细胞内位置，以提供有关其潜在体内底物的信息。

A new family of Ca2+-dependent protein kinases, called CDPKs, has recently been discovered. CDPKs are unique because they have a novel structure with a kinase domain joined to a Ca2+-binding domain similar to calmodulin. An important long term goal is to understand the function of CDPKs in Ca2+-mediated signal transduction pathways. The model plant system Arabidopsis has been chosen for this purpose. The foundation of the proposal is to determine how Ca2+ regulates CDPK activity. A biochemical and molecular genetic approach will be used to test a model referred to as a "stream-lined version of CaMK II". An E. coli. expression system has been developed to provide functional enzyme for this purpose. Two approaches will be pursued to investigate the biological functions of a specific CDPK isoform: 1) Isoform AK1 and a mutant "unregulated" version of AK1, will be over-expressed in transgenic plants to examine the effects of altering the balance of its activity in vivo. 2) AK1's intracellular location will be determined to provide information on its potential in vivo substrates.