Function of CDPK activation, localization and interaction with regulatory proteins during the induction of plant defence responses

钙依赖蛋白激酶(CDPK)是植物和某些原生生物特有的丝氨酸/苏氨酸蛋白激酶基因家族，其钙结合感受器结构域与蛋白激酶效应元件结构域直接相连。CDPKs参与了环境、生物和非生物信号诱导的应激反应的激活。然而，关于不同的CDPK亚型的生物学功能及其在体内的生化调控方面的信息仍然很少。我们在SPP1212中的关键问题是研究在MAP激酶信号转导的同时，CDPKs介导的钙依赖的信号通路是否也需要重新编程和激活早期的防御反应，从而触发植物的先天免疫。我们的目标是(1)从拟南芥中鉴定单个候选的CDPK亚型，并研究它们的生化激活及其在病原体和PAMP效应物诱导的防御反应中的作用，以及(2)评估CDPK信号是否代表了微生物效应物蛋白抑制病原体介导的防御反应的潜在靶点。

Calcium-dependent protein kinases (CDPK) are a gene family of serine/threonine protein kinases specific to plants and some protists, in which the regulatory calcium-binding sensor domain is directly linked to the protein kinase effector domain. CDPKs have been discussed to participate in the activation of environmental biotic and abiotic signal-induced stress responses. However, still little information has been available about the biological function of distinct CDPK isoforms and their biochemical regulation in vivo. Our key question within SPP1212 is to investigate whether in parallel to MAP kinase signalling also a calcium-dependent signalling pathway mediated by CDPKs is required for the reprogramming and activation of early defence responses triggering innate immunity in plants. Our objectives are (1) to identify single candidate CDPK isoforms from A. thaliana and investigate their biochemical activation and their role in pathogen and PAMP effector-induced defence responses, and (2) to assess whether CDPK signalling represents a potential target for pathogen-mediated defence suppression by microbial effector proteins.