H(v)1 Proton Channels in Dinoflagellates: Not Just for Bioluminescence?

Kigundu, Gabriel; Cooper, Jennifer L.; Smith, Susan M. E.

Bioluminescence in dinoflagellates is controlled by H(V)1 proton channels. Database searches of dinoflagellate transcriptomes and genomes yielded hits with sequence features diagnostic of all confirmed H(V)1, and show that H(V)1 is widely distributed in the dinoflagellate phylogeny including the basal species Oxyrrhis marina. Multiple sequence alignments followed by phylogenetic analysis revealed three major subfamilies of H(V)1 that do not correlate with presence of theca, autotrophy, geographic location, or bioluminescence. These data suggest that most dinoflagellates express a H(V)1 which has a function separate from bioluminescence. Sequence evidence also suggests that dinoflagellates can contain more than one H(V)1 gene.