Figure 1. Identification of essential regions for DCPIB inhibition in chimeras of 8A and 8C. (A) Alignment of the first extracellular loop (EL1) and the second TM domain (TM2) of LRRC8A and LRRC8C. The differences in TM2 are highlighted in More about this image found in Identification of essential regions for DCPIB inhibition in chimeras of 8A ...

Figure 2. Analysis of chimera TM2 mutations on DCPIB sensitivity. (A and B) Time course of 10 μM DCPIB-induced inhibition of 8A-8C(EL1+TM2) (n = 4) and 8A-8C(EL1+TM2)-M139L (n = 5) currents. (C) Effects of single point mutations in TM2 on More about this image found in Analysis of chimera TM2 mutations on DCPIB sensitivity. (A and B) Time cou...

Figure 3. Characteristics of DCPIB-dependent inhibition of 8C-8A(IL1 ²⁵ ) currents. (A) Representative whole-cell 8C-8A(IL1²⁵) current recorded from a cell dialyzed with normal pipette solution and cell swelling with hypotonic buffer (upper More about this image found in Characteristics of DCPIB-dependent inhibition of 8C-8A(IL1 ²⁵ ...

Figure 4. Analysis of 8C-8A(IL1 ²⁵ ) OCS and EL1 mutations on DCPIB sensitivity. (A and B) Top (upper panel) and side (bottom panel) views of the extracellular domains of 8C-8A(IL1²⁵) (PDB ID: 8DXN ) (B) Representative whole-cell currents of More about this image found in Analysis of 8C-8A(IL1 ²⁵ ) OCS and EL1 mutations on DCPIB sens...

Figure 5. Analysis of 8C-8A(IL1 ²⁵ ) TM2 mutations on DCPIB sensitivity. (A) Side (left) and top (right) views of the 8C-8A(IL1²⁵) TMD (PDB ID: 8DXN ) along with the solvent-accessible permeation pathway (gray surface) calculated using HOLE ( More about this image found in Analysis of 8C-8A(IL1 ²⁵ ) TM2 mutations on DCPIB sensitivity....

Figure 6. Analysis of 8C-8A(IL1 ²⁵ ) M48 mutations on DCPIB sensitivity. (A) Side view of the cryo-EM structure of 8C-8A(IL1²⁵) (PDB ID: 8DXN ) along with the solvent-accessible permeation pathway (gray surface) calculated using HOLE ( Smart More about this image found in Analysis of 8C-8A(IL1 ²⁵ ) M48 mutations on DCPIB sensitivity....

Figure 7. Analysis of 8C-8A(IL1 ²⁵ ) E6A mutation on DCPIB sensitivity. (A) Side view of the AlphaFold3 model of the entire pore region of 8C-8A(IL1²⁵) ( Yamada et al., 2025 ). Only two opposing subunits are shown. (B) Representative More about this image found in Analysis of 8C-8A(IL1 ²⁵ ) E6A mutation on DCPIB sensitivity. ...

Figure 8. Mutational analysis of DCPIB sensitivity in heteromeric 8A/8C currents. (A) Side (left) and top (right) views of 8A/8C heteromer (PDB ID: 8B41 ) ( Rutz et al., 2023 ). (B) Representative whole-cell heteromeric 8A/8C current recorded More about this image found in Mutational analysis of DCPIB sensitivity in heteromeric 8A/8C currents. (A)...

Figure 9. Effects of E6A and L136K mutations and extracellular low pH on tail currents. (A) Representative tail currents of 8C-8A(IL1²⁵)-E6A mutant recorded from a cell dialyzed with normal pipette solution and swollen with hypotonic buffer. More about this image found in Effects of E6A and L136K mutations and extracellular low pH on tail current...

Figure 10. Proposed multistep mechanism of DCPIB inhibition. DCPIB (orange, hydrophobic moiety; red, carboxylate group) inhibits LRRC8 channels through a dynamic, state-dependent process rather than by acting as a simple static pore plug. (OCS More about this image found in Proposed multistep mechanism of DCPIB inhibition. DCPIB (orange, hydrophob...

Figure 1. Structure of the pancreatic K _ATP channel. (A) Cartoon showing the transmembrane topology of the pancreatic K_ATP channel. Two (of four) Kir6.2 subunits are shown along with one (of four) SUR1 subunits. Red and green circles mark the More about this image found in Structure of the pancreatic K _ATP channel. (A) Cartoon showin...

Figure 2. Synthesis and characterization of TNP-AMP-PCP. (A) General reaction scheme for synthesis of TNP-AMP-PCP. The methylene group between the β and γ phosphates of AMP-PCP is highlighted in yellow. (B) UV/Vis absorbance and normalized More about this image found in Synthesis and characterization of TNP-AMP-PCP. (A) General reaction scheme...

Figure 3. Mass spectrometry of TNP-AMP-PCP. (A) Mass spectrum for TNP-AMP-PCP with electrospray ionization in negative-ion mode, showing a peak at the expected mass-to-charge (m/z) ratio (715 Da) for [TNP-AMP-PCP]⁻ as well as several peaks More about this image found in Mass spectrometry of TNP-AMP-PCP. (A) Mass spectrum for TNP-AMP-PCP with e...

Figure 4. ¹ H-NMR spectrum of TNP-AMP-PCP. (A) ¹H-NMR spectrum of TNP-AMP-PCP in D₂O. Peak assignments are based on the published spectrum of TNP-ATP ( Stephen et al., 2016 ). (B) pH dependence of the peaks at 8.7 and 8.8 ppm. The sample was More about this image found in ¹ H-NMR spectrum of TNP-AMP-PCP. (A) ¹H-NMR spectru...

Figure 5. Functional expression of ANAP-tagged K _ATP channels. (A) Schematic diagram of the SUR1-mOrange constructs used, showing the location of the two ANAP labeling sites (at positions 688 and 1,397). (B) Left: Bright-field and More about this image found in Functional expression of ANAP-tagged K _ATP channels. (A) Sche...

Figure 6. Measuring TNP-ATP binding to NBS1 of SUR1. (A) The top panels show mOrange and ANAP fluorescence from an unroofed HEK293T cell expressing Kir6.2/SUR1-W688ANAP channels with a C-terminal mOrange tag. In the bottom panel, the emitted More about this image found in Measuring TNP-ATP binding to NBS1 of SUR1. (A) The top panels show mOrange...

Figure 7. Binding of TNP-AMP-PCP to NBS1 and NBS2 of SUR1. Curves showing concentration-dependent quenching of Kir6.2/SUR1-W688ANAP (NBS1 labeled) and Kir6.2/SUR1-T1397ANAP (NBS2 labeled) by TNP-AMP-PCP. Both SUR1 constructs had C-terminal More about this image found in Binding of TNP-AMP-PCP to NBS1 and NBS2 of SUR1. Curves showing concentrat...

Figure 8. AMP-PCP binds to NBS2 of SUR1. (A) Fluorescence of Kir6.2/SUR1-T1397ANAP in the presence and absence of 5 µM TNP-ATP. (B) Fluorescence of Kir6.2/SUR1-T1397ANAP in the presence and absence of 5 µM TNP-ATP plus 100 µM AMP-PCP. (C) More about this image found in AMP-PCP binds to NBS2 of SUR1. (A) Fluorescence of Kir6.2/SUR1-T1397ANAP i...