|Viral rhodopsins 1 are an unique family of light-gated cation channels|Zabelskii, D.; Alekseev, A.; Kovalev, K.; Rankovic, V.; Balandin, T.; Soloviov, D.; Bratanov, D.; Savelyeva, E.; Podolyak, E.; Volkov, D.; Vaganova, S.; Astashkin, R.; Chizhov, I.; Yutin, N.; Rulev, M.; Popov, A.; Eria-Oliveira, A.S.; Rokitskaya, T.; Mager, T.; Antonenko, Y.; Rosselli, R.; Armeev, G.; Shaitan, K.; Vivaudou, M.; Büldt, G.; Rogachev, A.; Rodriguez-Valera, F.; Kirpichnikov, M.; Moser, T.; Offenhäusser, A.; Willbold, D.; Koonin, E.; Bamberg, E.; Gordeliy, V. (2020). Viral rhodopsins 1 are an unique family of light-gated cation channels. Nature Comm. 11(1): 5705. https://doi.org/10.1038/s41467-020-19457-7
In: Nature Communications. Nature Publishing Group: London. ISSN 2041-1723; e-ISSN 2041-1723, meer
ion transport; virus-host interactions
Phytoplankton is the base of the marine food chain as well as oxygen and carbon cycles and thus plays a global role in climate and ecology. Nucleocytoplasmic Large DNA Viruses that infect phytoplankton organisms and regulate the phytoplankton dynamics encompass genes of rhodopsins of two distinct families. Here, we present a functional and structural characterization of two proteins of viral rhodopsin group 1, OLPVR1 and VirChR1. Functional analysis of VirChR1 shows that it is a highly selective, Na+/K+-conducting channel and, in contrast to known cation channelrhodopsins, it is impermeable to Ca2+ ions. We show that, upon illumination, VirChR1 is able to drive neural firing. The 1.4 Å resolution structure of OLPVR1 reveals remarkable differences from the known channelrhodopsins and a unique ion-conducting pathway. Thus, viral rhodopsins 1 represent a unique, large group of light-gated channels (viral channelrhodopsins, VirChR1s). In nature, VirChR1s likely mediate phototaxis of algae enhancing the host anabolic processes to support virus reproduction, and therefore, might play a major role in global phytoplankton dynamics. Moreover, VirChR1s have unique potential for optogenetics as they lack possibly noxious Ca2+ permeability.