Elucidating the roles of voltage sensors in NaV1.9 activation and inactivation through a spider toxin

Shuijiao Peng; Minzhi Chen; Meijing Wu; Zhonghua Liu; Dongfang Tang; Xi Zhou

doi:10.1016/j.bbagen.2025.130762

Elucidating the roles of voltage sensors in Na_V1.9 activation and inactivation through a spider toxin

Biochim Biophys Acta Gen Subj. 2025 Jan 10:130762. doi: 10.1016/j.bbagen.2025.130762. Online ahead of print.

Authors

Shuijiao Peng¹, Minzhi Chen², Meijing Wu², Zhonghua Liu², Dongfang Tang³, Xi Zhou⁴

Affiliations

¹ The National and Local Joint Engineering Laboratory of Animal Peptide Drug Development, College of life sciences, Hunan Normal University, Changsha, China; Hunan Provincial Center for Disease Control and Prevention, Hunan Provincial Key Laboratory of Microbial Molecular Biology, Changsha 410000, Hunan, China.
² The National and Local Joint Engineering Laboratory of Animal Peptide Drug Development, College of life sciences, Hunan Normal University, Changsha, China; Peptide and small molecule drug R&D platform, Furong Laboratory, Hunan Normal University, Changsha 410081, Hunan, China; Institute of Interdisciplinary Studies, Hunan Normal University, Changsha 410081, China.
³ The National and Local Joint Engineering Laboratory of Animal Peptide Drug Development, College of life sciences, Hunan Normal University, Changsha, China; College of Chemistry and Bioengineering, Hunan University of Science and Engineering, Yongzhou, China. Electronic address: [email protected].
⁴ The National and Local Joint Engineering Laboratory of Animal Peptide Drug Development, College of life sciences, Hunan Normal University, Changsha, China; Peptide and small molecule drug R&D platform, Furong Laboratory, Hunan Normal University, Changsha 410081, Hunan, China; Institute of Interdisciplinary Studies, Hunan Normal University, Changsha 410081, China. Electronic address: [email protected].

PMID: 39800272
DOI: 10.1016/j.bbagen.2025.130762

Abstract

The gating process of voltage-gated sodium (Na_V) channels is extraordinary intrinsic and involves numerous factors, such as voltage-sensing domain (VSD), the N-terminus and C-terminus, and the auxiliary subunits. To date, the gating mechanism of Na_V channel has not been clearly elucidated. Na_V1.9 has garnered significant attention due to its slow gating kinetics. Due to the challenges of Na_V1.9 heterologous expression, research on its gating mechanism is relatively limited. Whether there are any differences in the functions of the four VSDs in Na_V1.9 compared to those in other subtypes remains an open question. Here, we employed the established chimera method to transplant the S3b-S4 motif from the VSDIV of the toxin-sensitive donor channel (Na_V1.9) into the receptor channel (Na_V1.9/1.8 DIV S3b-S4 chimera). This modification imparted animal toxin sensitivity to the other three VSDs. Our results demonstrate that all four VSDs of Na_V1.9 are involved in channel opening, VSDIII and VSDIV are primarily involved in regulating fast inactivation, and VSDII also regulates the steady-state inactivation of channels. These findings provide a new insight into the gating mechanism of Na_V1.9.

Keywords: HpTx-1; Na(V)1.9; S3b-S4 motif; Voltage sensing domain.