Imamura A, Hanaki N, Umeda H, Nakamura A, Suzuki T, Ueguchi C, Mizuno T
Laboratory of Molecular Microbiology, School of Agriculture, Nagoya University, Chikusa-ku, Nagoya 464, Japan.
Proc Natl Acad Sci U S A. 1998 Mar 3;95(5):2691-6. doi: 10.1073/pnas.95.5.2691.
The His to Asp phosphotransfer signal transduction mechanism involves three common signaling domains: the transmitter (or His-kinase), the receiver, and the histidine-containing phototransfer (HPt) domain. Typically, a sensor kinase has a His-kinase domain and a response regulator has a receiver domain containing a phosphoaccepting aspartate, whereas a histidine-containing phototransfer domain serves as a mediator of the histidine-to-aspartate phosphotransfer. This signal transduction mechanism was thought to be restricted to prokaryotes. However, many examples have been discovered in diverse eukaryotic species including higher plants. In Arabidopsis, three sensor kinases have been characterized, namely, ETR1, ERS, and CKI1, which were suggested to be involved in ethylene- and cytokinin-dependent signal transduction pathways, respectively. To date, no response regulator has been discovered in higher plants. We identify five distinct Arabidopsis response regulator genes, each encoding a protein containing a receiver-like domain. In vivo and in vitro evidence that ARRs can function as phosphoaccepting response regulators was obtained by employing the Escherichia coli His-Asp phosphotransfer signaling system.
传递器（或组氨酸激酶）、接收器和含组氨酸的磷酸转移（HPt）结构域。通常，一个传感激酶具有一个组氨酸激酶结构域，一个应答调节因子具有一个包含磷酸接受天冬氨酸的接收器结构域，而一个含组氨酸的磷酸转移结构域则作为组氨酸到天冬氨酸磷酸转移的介质。这种信号转导机制曾被认为仅限于原核生物。然而，在包括高等植物在内的多种真核生物中已发现许多实例。在拟南芥中，已鉴定出三种传感激酶，即ETR1、ERS和CKI1，它们分别被认为参与乙烯和细胞分裂素依赖的信号转导途径。迄今为止，在高等植物中尚未发现应答调节因子。我们鉴定出五个不同的拟南芥应答调节因子基因，每个基因编码一种含有类接收器结构域的蛋白质。通过利用大肠杆菌组氨酸-天冬氨酸磷酸转移信号系统，获得了体内和体外证据，证明ARR可作为磷酸接受应答调节因子发挥作用。
