Tirera, Fouley et al. (2019) International Worm Meeting "Roles of TCN-1 transmembrane protein in C. elegans osmosensation."

Hendricks, Michael, Penalva, Ylauna, Posner, Rachel, Tirera, Fouley, Tse, Victoria

[International Worm Meeting, 2019]

Maintaining a stable intracellular osmolarity is fundamental for the survival of all organisms. Extracellular osmotic changes perturb cellular functions, thus most organisms adopt physiologic and behavioural responses to adapt to and avoid osmotic stress. In mammals, members of the transient receptor potential vanilloid, also known as TRPV channels, are expressed in the osmosensory brain regions, however the underlying molecular mechanisms are not fully understood. In Caenorhabditis elegans, the OSM-9 TRPV channel is expressed in ASH sensory neurons and is involved in high osmolarity avoidance. On contact with a hyperosmotic stimulus, the nematode generates reversals to escape the high osmolarity region. Additionally, a previous study revealed that through RIM interneuron inhibition, food-deprived worms are willing to cross a high osmolarity barrier to reach an attractant, a food odour. Here we investigated the role of the uncharacterized transmembrane protein TCN-1 in osmosensation. We found that tcn-1 mutants display increased sensitivity to hyperosmotic barriers. Unlike wild type animals, food-deprived tcn-1 mutants will not cross a hyperosmotic barrier to reach an attractive odour, despite exhibiting normal locomotion and chemotaxis in the absence of a barrier. Therefore, our study demonstrates the TCN-1 transmembrane protein plays a role in osmosensation and might contribute to the regulation of intracellular osmolarity.

Owens, Hannah et al. (2021) International Worm Meeting "Characterizing the Role of the Mechanosensitive Ion Channel TACAN in C. elegans Osmosensation"

Davidova, Albena, Hendricks, Michael, Owens, Hannah, Tala Tirera, Fouley, Sharif-Naeini, Reza

[International Worm Meeting, 2021]

Mechanotransduction occurs via ion channels whose gating is controlled by mechanical stimuli. Recently, the transmembrane protein TACAN was identified as a mechanosensitive ion channel crucial for sensing mechanical pain in mice, and TACAN homologs were shown to be highly conserved across other species such as humans and nematodes. The nematode C. elegans is an ideal model organism to study the molecular properties of TACAN, given its mapped connectome, simple behavior, and capacity for genetic manipulations. Our preliminary data suggest that the uncharacterized TACAN homolog in C. elegans is involved in worm mechanosensation, specifically contributing to the detection of osmotic stimuli.