Department of Biological Sciences, Dartmouth College, Hanover, NH, USA.
Plant Signal Behav. 2009 Dec;4(12):1152-3. doi: 10.4161/psb.4.12.9943.
The phytohormone ethylene is perceived in Arabidopsis by a five-member receptor family. Earlier work has demonstrated that the basic functional unit for an ethylene receptor is a disulfide-linked homodimer. We recently reported in The Journal of Biological Chemistry that the ethylene-receptor ETR1 physically associates with other ethylene receptors through higher order interactions, suggesting the existence of receptor clusters. Here we consider the implications of such clusters upon the mechanism of ethylene signal transduction. In particular, we consider how such clustering provides a cooperative mechanism, akin to what has been found for the prokaryotic chemoreceptors, by which plant sensitivity to ethylene may be increased. In addition, we consider how the dominant ethylene insensitivity conferred by some receptor mutations, such as etr1-1, may also be propagated by interactions among members of the ethylene receptor family.
植物激素乙烯在拟南芥中被一个五成员受体家族所感知。早期的研究表明，乙烯受体的基本功能单元是一个二硫键连接的同源二聚体。我们最近在《生物化学杂志》上报道，乙烯受体 ETR1 通过更高阶的相互作用与其他乙烯受体物理结合，这表明受体簇的存在。在这里，我们考虑了这种簇对乙烯信号转导机制的影响。特别是，我们考虑了这种聚类如何提供一种协作机制，类似于已经在原核化学感受器中发现的机制，通过这种机制，植物对乙烯的敏感性可能会增加。此外，我们还考虑了一些受体突变（如 etr1-1）赋予的乙烯不敏感性是如何通过乙烯受体家族成员之间的相互作用来传播的。
