Potassium ion (K+) channels have been observed in diverse viruses that infect eukaryotic marine and freshwater algae. However, experimental evidence for functional K+ channels among these alga-infecting viruses has thus far been restricted to members of the family Phycodnaviridae, which are large, double-stranded DNA viruses within the phylum Nucleocytoviricota. Recent sequencing projects revealed that alga-infecting members of Mimiviridae, another family within this phylum, may also contain genes encoding K+ channels. Here we examine the structural features and the functional properties of putative K+ channels from four cultivated members of Mimiviridae. While all four proteins contain variations of the conserved selectivity filter sequence of K+ channels, structural prediction algorithms suggest that only two of them have the required number and position of two transmembrane domains that are present in all K+ channels. After in vitro translation and reconstitution of the four proteins in planar lipid bilayers, we confirmed that one of them, a 79 amino acid protein from the virus Tetraselmis virus 1 (TetV-1), forms a functional ion channel with a distinct selectivity for K+ over Na+ and a sensitivity to Ba2+. Thus, virus-encoded K+ channels are not limited to Phycodnaviridae but also occur in the members of Mimiviridae. The large sequence diversity among the viral K+ channels implies multiple events of lateral gene transfer.
A functional K+ channel from tetraselmis virus 1, a member of the mimiviridae / K. Kukovetz, B. Hertel, C.R. Schvarcz, A. Saponaro, M. Manthey, U. Burk, T. Greiner, G.F. Steward, J.L. van Etten, A. Moroni, G. Thiel, O. Rauh. - In: VIRUSES. - ISSN 1999-4915. - 12:10(2020 Sep 29).
|Titolo:||A functional K+ channel from tetraselmis virus 1, a member of the mimiviridae|
|Parole Chiave:||K; +; channel evolution; Kcv; Mimiviridae; Phycodnaviridae; Viral K; +; channel|
|Settore Scientifico Disciplinare:||Settore BIO/04 - Fisiologia Vegetale|
Settore BIO/11 - Biologia Molecolare
|Progetto:||Noninvasive Manipulation of Gating in Ion Channels|
|Data di pubblicazione:||29-set-2020|
|Digital Object Identifier (DOI):||http://dx.doi.org/10.3390/v12101107|
|Appare nelle tipologie:||01 - Articolo su periodico|