Two types of inactivation in Shaker K+ channels: effects of alterations in the carboxy-terminal region

Neuron. 1991 Oct;7(4):547-56. doi: 10.1016/0896-6273(91)90367-9.


Shaker potassium channels inactivate and recover from inactivation with multiple exponential components, suggesting the presence of multiple inactivation processes. We describe two different types of inactivation in Shaker potassium channels. N-type inactivation can occur as rapidly as a few milliseconds and has been shown to involve an intracellular region at the amino-terminal acting as a blocker of the pore. C-type inactivation is independent of voltage over a range of -25 to +50 mV. It does not require intact N-type inactivation, but is partially coupled to it. The kinetics of C-type inactivation are quite different for channels with different alternatively spliced carboxy-terminal regions. We have localized the differences in C-type inactivation between the ShB and ShA variants to a single amino acid in the sixth membrane-spanning region. N- and C-type inactivation occur by distinct molecular mechanisms.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Drosophila / genetics*
  • Kinetics
  • Mutation*
  • Oocytes / metabolism
  • Potassium Channels / chemistry
  • Potassium Channels / physiology*
  • Time Factors
  • Xenopus


  • Potassium Channels