紀要論文

細菌走化性受容体クラスターにおけるダイマー間相互作用の解析

jpn

21879923

https://doi.org/10.15002/00013459

法政大学大学院理工学・工学研究科

57

1

2

2016-03-24

Version of Record

ヘッダー部分に誤記 ; (誤) 法政大学大学院理工学・工学研究科紀要 (正) 法政大学大学院紀要. 理工学・工学研究科編

Escherichia coli have very low threshold concentrations for attractant responses: e.g. ~3 х 10 -8 M L-aspartate. Moreover, E. coli has high sensitivity, responding to a very small change (less than 1%) in the receptor occupancy with an attractant. Taken together, an input signal has to be mplified to produce a significant response. It is thought that this amplification involves the interdimer interaction of chemoreceptors within a huge receptor-kinase cluster at a cell pole. However, it is generally difficult to analyze spatial arrangements and interactions of integral membrane proteins. Previous site-directed disulfide cross-linking analyses of this laboratory showed that interdimer interaction is important for signal amplification. However, it has not been examined whether attractant binding to one receptor also affects neighboring receptor dimers in the cluster. In this study, I examined the interactions between dimers of the aspartate chemoreceptor Tar and the serine chemoreceptor Tsr, using in vivo disulfide cross-linking assay. I found that attractant binding to Cys-replaced Tar dimers not only affected cross-linking between Tar dimers but also influenced interdimer cross-linking of Tar-Tsr and Tsr-Tsr. These results suggest that a ligand-bound receptor dimer communicates with neighboring apo receptor dimers to trigger a cooperative conformational change, resulting in signal amplification.

Article

AA12677220