Title

Selenoprotein T is required for pathogenic bacteria avoidance in Caenorhabditis elegans

UMMS Affiliation

Department of Neurobiology; Alkema Lab

Date

3-24-2017

Document Type

Article

Disciplines

Biochemistry, Biophysics, and Structural Biology | Ecology and Evolutionary Biology | Neuroscience and Neurobiology

Abstract

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

Related Resources

Link to Article in PubMed

Keywords

C. elegans, Nematode, Pathogenic bacteria avoidance, Pseudomonas aeruginosa, SelT, SelenoT, Selenocysteine, Selenoprotein T, Serratia marcescens

PubMed ID

28347729