An animal toxin-antidote system kills cells by creating a novel cation channel
Fig 4
PEEL-1’s amphipathic helix is critical for toxicity.
(A) The AlphaFold2 predicted structure of PEEL-1 and (B) a helical wheel representation of the putative PEEL-1 amphipathic helix. Amphipathic helix residues are colored (pink = hydrophobic, blue = hydrophilic). (C) Cytotoxicity of a series of PEEL-1 C-terminal truncations expressed in HEK293T cells. The number of amino acids removed are indicated (ex. “−28” means the last 28 residues were removed). Each truncation removes an additional alpha helix. The “−65” truncation removes the amphipathic helix. (D) Percent dead worms after heat-shock PEEL-1 expression of the indicated truncation mutant. Fifty worms were assayed for each data point, and two independent transgenic lines were tested for each construct. (E) Cytotoxicity of PEEL-1 amphipathic helix missense mutants in HEK293T cells. Mutants are ordered by descending hydrophobic moment (µH). Six single mutants (left of dotted line) and three double mutants are shown (right of dotted line). All bar graphs show mean with SD. Statistics were performed using multiple unpaired t-tests with Holm-Šídák test, comparing each PEEL-1 alone to PEEL-1 and PMPL-1 (**p < 0.01; ***p < 0.001; ****p < 0.0001). (F) The average toxicity of missense mutants from (E) plotted against their hydrophobic moment. Underlying data are available in S1 Data.