Selenoprotein T is required for pathogenic bacteria avoidance in Caenorhabditis elegans
Department of Neurobiology; Alkema Lab
Biochemistry, Biophysics, and Structural Biology | Ecology and Evolutionary Biology | Neuroscience and Neurobiology
Selenoprotein T (SELENOT) is an endoplasmatic reticulum (ER)-associated redoxin that contains the amino acid selenocysteine (Sec, U) within a CXXU motif within a thioredoxin-like fold. Its precise function in multicellular organisms is not completely understood although it has been shown in mammals to be involved in Ca2+ homeostasis, antioxidant and neuroendocrine functions. Here, we use the model organism C. elegans to address SELENOT function in a whole organism throughout its life cycle. C. elegans possess two genes encoding SELENOT protein orthologues (SELT-1.1 and SELT-1.2), which lack Sec and contain the CXXC redox motif instead. Our results show that a Sec-->Cys replacement and a gene duplication were two major evolutionary events that occurred in the nematode lineage. We find that worm SELT-1.1 localizes to the ER and is expressed in different cell types, including the nervous system. In contrast, SELT-1.2 exclusively localizes in the cytoplasm of the AWB neurons. We find that selt-1.1 and selt-1.2 single mutants as well as the double mutant are viable, but the selt-1.1 mutant is compromised under rotenone-induced oxidative stress. We demonstrate that selt-1.1, but not selt-1.2, is required for avoidance to the bacterial pathogens Serratia marcescens and Pseudomonas aeruginosa. Aversion to the noxious signal 2-nonanone is also significantly impaired in selt-1.1, but not in selt-1.2 mutant animals. Our results suggest that selt-1.1 would be a redox transducer required for nociception and optimal organismal fitness. The results highlight C. elegans as a valuable model organism to study SELENOT-dependent processes.
Rights and Permissions
Citation: Free Radic Biol Med. 2017 Mar 24;108:174-182. doi: 10.1016/j.freeradbiomed.2017.03.021. [Epub ahead of print] Link to article on publisher's site
C. elegans, Nematode, Pathogenic bacteria avoidance, Pseudomonas aeruginosa, SelT, SelenoT, Selenocysteine, Selenoprotein T, Serratia marcescens
Romanelli-Cedrez, Laura; Carrera, Ines; Otero, Lucia; Miranda-Vizuete, Antonio; Mariotti, Marco; Alkema, Mark J.; and Salinas, Gustavo, "Selenoprotein T is required for pathogenic bacteria avoidance in Caenorhabditis elegans" (2017). Neurobiology Publications and Presentations. 205.