Journal: bioRxiv

Article Title: Constitutive sodium permeability in a C. elegans two-pore domain potassium channel

doi: 10.1101/2024.01.22.576648

Figure Lengend Snippet: A Average traces of Ca 2+ responses of ALM neurons stimulated using a “short press” touch protocol in control (n=37), gain-of-function unc-58(e665) (n=29) and loss-of-function unc-58(bln223) (n=36) animals expressing the ratiometric calcium sensor YC3.60 in mechanosensory neurons. Orange bars indicate duration of physical stimulus. Black trace, mean CFP/YFP ratio change, ΔR (%). Grey trace, standard deviation. B Touch response of ALM mechanosensory neurons is modulated by mutation of unc-58 . Left, proportion of ALM neurons responding to short press mechanical stimulus in wild type (n=37), gain-of-function mutant unc-58(e665) (n=29) and loss-of-function mutant unc-58(bln223) (n=36). P=0.0039 (wild type vs. unc-58(e665)) and 0.0193 (wild type vs. unc-58(bln223)) , Fisher’s exact test. Right, ratio change, ΔR (%) of calcium response. P<0.0001 and p=0.0084, respectively, Mann-Whitney test. Each data point represents the response of one ALM neuron. Non-responders, empty circles. C Resting membrane potential of C. elegans body wall muscles from wild type (n=7) and gain-of-function mutant unc-58(bln205) (n=7). Line, median; whiskers, standard deviation. Mann-Whitney test, ** p < 0.005.

Article Snippet: Animal movements were recorded using an AZ100 Multizoom (Nikon) equipped with a Flash 4.0 CMOS camera (Hamamatsu Photonics) and analyzed using the C. elegans tracking software WormLab (MBF Bioscience).

Techniques: Expressing, Standard Deviation, Mutagenesis, MANN-WHITNEY, Membrane, Muscles

Journal: bioRxiv

Article Title: Constitutive sodium permeability in a C. elegans two-pore domain potassium channel

doi: 10.1101/2024.01.22.576648

Figure Lengend Snippet: A Alignment of SF1 and SF2 selectivity filter sequences from selected human and C. elegans K2P channels. The SF1 and SF2 residues are labeled in red and blue, respectively. UNC-58 is the only channel containing a cysteine residue (in bold and underlined) at the second position of the TxGYG SF1 motif. B Structural model of the UNC-58 dimer, modeled with AlphaFold and used for molecular dynamics simulations. Individual subunits are labeled in orange and purple. Transmembrane helix M3 and SF2 have been omitted for clarity. The inset represents the SF1 region and shows opposing selectivity filter loops belonging two each subunit. K + ions (green spheres) are coordinated at position S2 and S4 within the selectivity filter, while positions S1 and S3 are occupied by water molecules. C-F Upper panels indicate the distance between the S2 ion and the oxygen atom of the C266 carbonyl backbone during molecular dynamics (MD) simulations for wild type (WT) UNC-58 with K + (C) or Na + (D) and for the UNC-58 C266I mutant with K + (E) or Na + (F). Oxygen atoms within a confinement radius of 3.5 Å around the ion (red dotted lines) are counted as coordinating. Lower panels show representative licorice structures at the beginning (0 ns) and at the end (200 ns) of MD simulation. The residues of the SF1 selectivity filter of chain A and B are shown in orange and purple, respectively. K + and Na + ions are showed as green and cyan spheres, respectively.

Article Snippet: Animal movements were recorded using an AZ100 Multizoom (Nikon) equipped with a Flash 4.0 CMOS camera (Hamamatsu Photonics) and analyzed using the C. elegans tracking software WormLab (MBF Bioscience).

Techniques: Labeling, Residue, Mutagenesis