The solute carrier SLC9C1 is a Na⁺/H⁺-exchanger gated by an S4-type voltage-sensor and cyclic-nucleotide binding.

ABSTRACT: Voltage-sensing (VSD) and cyclic nucleotide-binding domains (CNBD) gate ion channels for rapid electrical signaling. By contrast, solute carriers (SLCs) that passively redistribute substrates are gated by their substrates themselves. Here, we study the orphan sperm-specific solute carriers SLC9C1 that feature a unique tripartite structure: an exchanger domain, a VSD, and a CNBD. Voltage-clamp fluorimetry shows that SLC9C1 is a genuine Na⁺/H⁺ exchanger gated by voltage. The cellular messenger cAMP shifts the voltage range of activation. Mutations in the transport domain, the VSD, or the CNBD strongly affect Na⁺/H⁺ exchange, voltage gating, or cAMP sensitivity, respectively. Our results establish SLC9C1 as a phylogenetic chimaera that combines the

SUBMITTER: Windler F 

PROVIDER: S-EPMC6052114 | biostudies-literature | 2018 Jul

REPOSITORIES: biostudies-literature