Chico Jose M, Chini Andrea, Fonseca Sandra, Solano Roberto
Departamento de Genética Molecular de Plantas, Centro Nacional de Biotecnología-CSIC, Campus Universidad Autónoma, 28049 Madrid, Spain.
Curr Opin Plant Biol. 2008 Oct;11(5):486-94. doi: 10.1016/j.pbi.2008.06.003. Epub 2008 Jul 22.
Jasmonates (JAs) are essential hormones for plant defense and development. In spite of their importance, the molecular details of their signaling pathways remain largely unknown. A new family of regulators of JA signaling named JAZ, jasmonate ZIM-domain proteins, has recently been described. JAZ proteins repress of JA signaling and are targeted by the E3-ubiquitin ligase SCF(COI1) for proteasome degradation in response to JA. Hormone binding depends on a functional COI1 protein suggesting that COI1 is the JA receptor. MYC2, a positive regulator of JA-dependent responses, has been identified as a target of JAZ repressors. Interestingly, MYC2 and JAZ proteins are involved in a negative regulatory feedback loop, suggesting a model to explain how transcriptional reprogramming is turned on and off in response to JA. The discovery of JAZ repressors provides a new framework to understand JA-signaling pathways from hormonal perception to transcriptional activation.
茉莉酸（JAs）是植物防御和发育所必需的激素。尽管它们很重要，但其信号通路的分子细节仍 largely unknown。最近描述了一个名为JAZ的茉莉酸信号调节因子新家族，即茉莉酸ZIM结构域蛋白。JAZ蛋白抑制茉莉酸信号传导，并被E3泛素连接酶SCF(COI1)靶向，以便在响应茉莉酸时进行蛋白酶体降解。激素结合依赖于功能性COI1蛋白，这表明COI1是茉莉酸受体。MYC2是茉莉酸依赖性反应的正调节因子，已被确定为JAZ阻遏物的靶标。有趣的是，MYC2和JAZ蛋白参与负调节反馈回路，这提示了一个模型来解释转录重编程如何响应茉莉酸而开启和关闭。JAZ阻遏物的发现为理解从激素感知到转录激活的茉莉酸信号通路提供了一个新框架。
