Identification of an HV 1 voltage-gated proton channel in insects.
FEBS J
; 283(8): 1453-64, 2016 Apr.
Article
em En
| MEDLINE
| ID: mdl-26866814
ABSTRACT
UNLABELLED The voltage-gated proton channel 1 (HV 1) is an important component of the cellular proton extrusion machinery and is essential for charge compensation during the respiratory burst of phagocytes. HV 1 has been identified in a wide range of eukaryotes throughout the animal kingdom, with the exception of insects. Therefore, it has been proposed that insects do not possess an HV 1 channel. In the present study, we report the existence of an HV 1-type proton channel in insects. We searched insect transcriptome shotgun assembly (TSA) sequence databases and found putative HV 1 orthologues in various polyneopteran insects. To confirm that these putative HV 1 orthologues were functional channels, we studied the HV 1 channel of Nicoletia phytophila (NpHV 1), an insect of the Zygentoma order, in more detail. NpHV 1 comprises 239 amino acids and is 33% identical to the human voltage-gated proton channel 1. Patch clamp measurements in a heterologous expression system showed proton selectivity, as well as pH- and voltage-dependent gating. Interestingly, NpHV 1 shows slightly enhanced pH-dependent gating compared to the human channel. Mutations in the first transmembrane segment at position 66 (Asp66), the presumed selectivity filter, lead to a loss of proton-selective conduction, confirming the importance of this aspartate residue in voltage-gated proton channels. DATABASE Nucleotide sequence data have been deposited in the GenBank database under accession number KT780722.
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MEDLINE
Assunto principal:
Prótons
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Ativação do Canal Iônico
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Membrana Celular
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Insetos
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Canais Iônicos
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Potenciais da Membrana
Idioma:
En
Ano de publicação:
2016
Tipo de documento:
Article