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1. Introduction
2. The action potential (AP)
3. Voltage-dependent channels and the AP
4. Channel gating during the AP
5. Voltage-dependent ion channels
6. Different channels alter AP
7. Voltage-dependent ionic current
8. Charge movement triggers gating
9. Measuring voltage sensor movement
10. Voltage-dependent gating current
11. Gating vs. ionic current
12. Protein sequence reveals voltage sensor
13. Segregated functions within the protein
14. KV channels comprised of 4 subunits
15. NaV channels have four domains
16. CaV channels also have four domains
17. S4 homology
18. Evidence for S4 movement
19. Cysteine modification method (1)
20. Cysteine modification method (2)
21. S4 moves
22. The extent of S4 movement
23. Similar conclusions for KV channels
24. S4 is exposed to the cytoplasm
25. S4 moves through a gating pore
26. Pathogenic mutations and the gating pore
27. Different functions within one domain
28. The activation/deactivation gate
29. Different models of S4 movement
30. Summary

Topics Covered

• Voltage-dependent ion channels
• Critical to proper nerve and muscle function
• Voltage sensitivity is mediated by positively charged segments of the protein
• These voltage sensors move outward with depolarization to trigger channel opening
• The return of one sensor to the resting positions closes the channel
• Hypothesized mechanisms of voltage sensor movement are detailed

Links

Series:

• Ion Channels

Categories:

• Biochemistry

Talk Citation

Publication History

• Published on March 3, 2011

Financial Disclosures

• Dr. Keith S. Elmslie, Grant/Research Support (Principal Investigator): National Institutes of Health, National Institute of Arthritis and Musculoskeletal and Skin Diseases AR059397