Identification and characterization of two zebrafish Twik related potassium channels, Kcnk2a and Kcnk2b

Figures

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  Figure 1. (A–C) Recorded currents at 0 mV potential by applying an increased negative pressure from 0 to −80 mmHg on HEK cells transfected with kcnk2a-pIRES-2-eGFP in CA configuration (n = 3) (A) on HEK cells transfected with pIRES-2-eGFP in CA (n = 4) (B) and their corresponding current/pressure curves (C). (D–F) Recorded currents at 0 mV potential by applying an increased negative pressure from 0 to −80 mmHg on HEK cells transfected with kcnk2a-pIRES-2-eGFP in IO configuration (n = 7) (D) on HEK cells transfected with pIRES-2-eGFP in IO configuration (n = 4) (E) and their corresponding current/pressure curves (F). *P value < 0.05; **P value < 0.01. (G) Recorded currents in IO configuration by applying a voltage ramp going from −100 to +100 mV on HEK cells transfected with kcnk2a-pIRES-2-eGFP at pH 7.2 (black line) at pH 6.2 (red line) at pH 6.2 (blue line) (n = 9). Recorded currents on HEK cells transfected with pIRES-2eGFP at pH 5.2 (green line) (n = 3). (H) Typical graph showing the current amplitudes at 0 mV potential for each test conditions, *P value < 0.05; **P value < 0.01.

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  Figure 2. (A–C) Recorded currents at 0 mV potential by applying an increased negative pressure from 0 to −80 mmHg on HEK cells transfected with kcnk2b-pIRES-2-eGFP in CA configuration (n = 8) (A) on HEK cells transfected with pIRES-2-eGFP in CA (n = 4) (B) and their corresponding current/pressure curves (C). (D–F) Recorded currents on HEK cells transfected with kcnk2b-pIRES-2-eGFP in IO configuration (n = 19) (D) on HEK cells transfected with pIRES-2-eGFP in IO configuration (n = 4) (E) and their corresponding current/pressure curves (F). **P value < 0.01; ***P value < 0.001. (G) Recorded currents in IO configuration by applying a voltage ramp going from −100 to +100 mV on HEK cells transfected with kcnk2b-pIRES-2-eGFP at pH 7.2 (black line) at pH 6.2 (red line) at pH 6.2 (blue line) (n = 11). Recorded currents on HEK cells transfected with pIRES-2eGFP at pH 5.2 (green line) (n = 3). (H) Typical graph showing the current amplitudes at 0 mV potential for each test conditions, **P value < 0.01.

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  Figure 3. (A,B,E,F) Recorded currents in WC configuration by applying a voltage steps protocole going from −100 to + 60 mV by – 20 mV increments. on HEK cells transfected with kcnk2a-pIRES-2-eGFP in the presence of potassium cocktail blockers (A,E) (n = 5), in the presence of potassium cocktail blockers and unsaturated fatty acid 10 µM of Docosahexaenoic acid (DHA) (n = 5) (B) or 10 µM of arachidonic acid (AA) (n = 5) (F). (C,G) Recorded currents on HEK cells transfected pIRES-2-eGFP in presence of the potassium cocktail blockers and 10 µM of each polyunsaturated fatty acid DHA (n = 5) (C) or AA (n = 5) (G). (D,H) Corresponding Current/potential curves for each tested condition.

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  Figure 4. (A,B,E,F) Recorded currents in WC configuration by applying a voltage steps protocole going from −100 to +60 mV by −20 mV increments on HEK cells transfected with kcnk2b-pIRES-2-eGFP in the presence of potassium cocktail blockers (n = 5) (A,E) in the presence of potassium cocktail blockers and unsaturated fatty acid 10 µM of Docosahexaenoic acid (DHA) (n = 5) (B) or 10 µM of arachidonic acid (AA) (n = 5) (F). (C,G) Recorded currents on HEK cells transfected pIRES-2-eGFP in presence of the potassium cocktail blockers and 10 µM of each polyunsaturated fatty acid DHA (n = 5) (C) or AA (n = 5) (G). (D,H) Corresponding Current/potential curves for each tested condition.

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  Figure 5. Recorded currents in IO configuration by applying an increasing negative pressure protocol from 0 to −80 mmHg by – 10 mmHG pressure step increments on HEK cells transfected with kcnk2a-pIRES-2-eGFP (control condition) (n = 7) (A) in the presence of 10 µM of spadin into the pipette medium (n = 6) (B) and their corresponding current/pressure curves (C). Recorded currents in IO configuration by applying an increasing negative pressure protocol from 0 to −80 mmHg by – 10 mmHG pressure step increments on HEK cells transfected with kcnk2b-pIRES-2-eGFP (control condition) (n = 7) (D) in the presence of 10 µM of spadin into the pipette medium (n = 6) (E) and their corresponding current/pressure curves (F). *P value < 0.05, ***P value < 0.001.