Click here to close
Hello! We notice that you are using Internet Explorer, which is not supported by Xenbase and may cause the site to display incorrectly.
We suggest using a current version of Chrome,
FireFox, or Safari.
Channels (Austin)
2011 Jan 01;53:225-7. doi: 10.4161/chan.5.3.15313.
Show Gene links
Show Anatomy links
The "structurally minimal" isoform KChIP2d modulates recovery of K(v)4.3 N-terminal deletion mutant Δ2-39.
Hovind LJ, Campbell DL.
???displayArticle.abstract???
Mechanisms underlying K(v)4 (Shal type) potassium channel macroscopic (open state) inactivation and recovery are unknown, as are mechanisms by which KChIP2 isoforms modulate these two processes. In a recent study (Xenopus oocytes, 2 microelectrode voltage clamp) we demonstrated that: i) Partial deletion of the K(v)4.3 proximal N-terminal domain (Δ2-39; deletes N-terminal amino acids 2-39) not only slowed macroscopic inactivation, but also slowed the net rate of recovery; and ii) Co-expression of KChIP2b significantly accelerated the rate Δ2-39 recovery from inactivation. The latter effect demonstrated that an intact N-terminal domain was not obligatorily required for KChiP2b-mediated modulation of K(v)4.3 recovery. To extend these prior observations, we have employed identical protocols to determine effects of KChiP2d on Δ2-39 macroscopic recovery. KChiP2d is a "structurally minimal" isoform (consisting of only the last 70 amino acids of the common C-terminal domain of larger KChIP2 isoforms) that exerts functional modulatory effects on native K(v)4.3 channels. We demonstrate that KChiP2d also accelerates Δ2-39 recovery from macroscopic inactivation. Consistent with our prior Δ2-39 + KChIP2b study, these Δ2-39 + KChIP2d results: i) Further indicate that KChIP2 isoform-mediated acceleration of K(v)4.3 macroscopic recovery is not obligatorily dependent upon an intact proximal N-terminal; and ii) Suggest that the last 70 amino acids of the common C-terminal of KChiP2 isoforms may contain the domain(s) responsible for modulation of recovery.
Aldrich,
Fifty years of inactivation.
2001, Pubmed
Aldrich,
Fifty years of inactivation.
2001,
Pubmed Amadi,
Regulation of Kv4.3 closed state inactivation and recovery by extracellular potassium and intracellular KChIP2b.
2007,
Pubmed
,
Xenbase Bähring,
Conserved Kv4 N-terminal domain critical for effects of Kv channel-interacting protein 2.2 on channel expression and gating.
2001,
Pubmed Bähring,
Kinetic analysis of open- and closed-state inactivation transitions in human Kv4.2 A-type potassium channels.
2001,
Pubmed Barghaan,
Role of N-terminal domain and accessory subunits in controlling deactivation-inactivation coupling of Kv4.2 channels.
2008,
Pubmed Callsen,
Contribution of N- and C-terminal Kv4.2 channel domains to KChIP interaction [corrected].
2005,
Pubmed Cordero-Morales,
Molecular driving forces determining potassium channel slow inactivation.
2007,
Pubmed
,
Xenbase Covarrubias,
The neuronal Kv4 channel complex.
2008,
Pubmed Cuello,
Structural mechanism of C-type inactivation in K(+) channels.
2010,
Pubmed Han,
C-terminal domain of Kv4.2 and associated KChIP2 interactions regulate functional expression and gating of Kv4.2.
2006,
Pubmed Hovind,
K(V)4.3 N-terminal deletion mutant Δ2-39: effects on inactivation and recovery characteristics in both the absence and presence of KChIP2b.
2011,
Pubmed
,
Xenbase Kaulin,
Mechanism of the modulation of Kv4:KChIP-1 channels by external K+.
2008,
Pubmed
,
Xenbase Kim,
Three-dimensional structure of I(to); Kv4.2-KChIP2 ion channels by electron microscopy at 21 Angstrom resolution.
2004,
Pubmed Niwa,
Molecular determinants of cardiac transient outward potassium current (I(to)) expression and regulation.
2010,
Pubmed Patel,
Transient outward potassium current, 'Ito', phenotypes in the mammalian left ventricle: underlying molecular, cellular and biophysical mechanisms.
2005,
Pubmed Patel,
Heterogeneous expression of KChIP2 isoforms in the ferret heart.
2002,
Pubmed
,
Xenbase Patel,
Elucidating KChIP effects on Kv4.3 inactivation and recovery kinetics with a minimal KChIP2 isoform.
2002,
Pubmed
,
Xenbase Patel,
Regulation of Kv4.3 voltage-dependent gating kinetics by KChIP2 isoforms.
2004,
Pubmed
,
Xenbase Pioletti,
Three-dimensional structure of the KChIP1-Kv4.3 T1 complex reveals a cross-shaped octamer.
2006,
Pubmed
,
Xenbase Wang,
Time- and voltage-dependent components of Kv4.3 inactivation.
2005,
Pubmed
,
Xenbase Wang,
Structural basis for modulation of Kv4 K+ channels by auxiliary KChIP subunits.
2007,
Pubmed
,
Xenbase Yellen,
The moving parts of voltage-gated ion channels.
1998,
Pubmed
