An L319F mutation in transmembrane region 3 (TM3) selectively reduces sensitivity to okaramine B of the Bombyx mori l-glutamate-gated chloride channel

Shogo Furutani, Daiki Okuhara, Anju Hashimoto, Makoto Ihara, Kenji Kai, Hideo Hayashi, David B. Sattelle, Kazuhiko Matsuda
2017 Bioscience, biotechnology and biochemistry  
Abbreviations. Bombyx mori L-Glutamate-gated chloride channel, BmGluCl; Bombyx mori γ-aminobutyric acid-gated chloride channel, BmGABACl; third transmembrane (TM3) Abstract Okaramines produced by Penicillium simplicissimum AK-40 activate L-glutamate-gated chloride channels (GluCls) and thus paralyze insects. However, the okaramine binding site on insect GluCls is poorly understood. Sequence alignment shows that the equivalent of residue Leucine319 of the okaramine B sensitive Bombyx mori GluCl
more » ... s a phenylalanine in the okaramine B insensitive B. mori γ-aminobutyric acid-gated chloride channel (BmGABACl) of the same species. This residue is located in the third transmembrane (TM3) region, a location which in a nematode GluCl is close to the ivermectin binding site. The B. mori GluCl containing the L319F mutation retained its sensitivity to L-glutamate, but responses to ivermectin were reduced and those to okaramine B were completely blocked.
doi:10.1080/09168451.2017.1359487 pmid:28825521 fatcat:gzesx565pbdmddljiggywxi2gu