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Updated: Jun 28, 2026
11:33
Isolation and Kv Channel Recordings in Murine Atrial and Ventricular Cardiomyocytes
Published on: March 12, 2013
A novel DPP6 isoform (DPP6-E) can account for differences between neuronal and reconstituted A-type K(+) channels
Jonathon Maffie1, Timothy Blenkinsop, Bernardo Rudy
1Department of Physiology & Neuroscience, New York University School of Medicine, New York, NY 10016, USA.
Neuroscience Letters
|November 15, 2008
Summary
A newly identified DPP6-E protein isoform creates fast-activating potassium (K+) channels in neurons. This discovery explains variations in native Kv4 channel function and the diversity of A-type K+ currents in the brain.
Area of Science:
- Neuroscience
- Molecular Biology
- Ion Channel Physiology
Background:
- Somatodendritic A-type K+ currents are crucial for neuronal function.
- These currents are mediated by Kv4 channels complexed with K+ channel interacting proteins (KChIPs) and dipeptidyl-peptidase-like (DPPL) proteins.
- Native A-type currents exhibit faster kinetics than those reconstituted in heterologous systems.
Purpose of the Study:
- To characterize a novel DPP6 spliced isoform, DPP6-E.
- To investigate the biophysical properties of Kv4 channels formed with DPP6-E.
- To explain discrepancies between native and reconstituted Kv4 channel kinetics.
Main Methods:
- Heterologous expression of Kv4.2, KChIP1, and DPP6 isoforms.
- Electrophysiological recordings (two-electrode voltage-clamp) to measure K+ currents.
- Quantitative real-time PCR to assess tissue-specific expression of DPP6 isoforms.
Main Results:
- DPP6-E forms ternary Kv4 channels with significantly faster kinetics in heterologous cells.
- DPP6-E is selectively expressed in specific neuronal populations, including cerebellar granule neurons, hippocampal pyramidal cells, and superior colliculus neurons.
- The inclusion of DPP6-E in Kv4 channel complexes recapitulates the fast kinetics observed in native neuronal A-type currents.
Conclusions:
- The DPP6-E isoform is responsible for the rapid kinetics of native A-type K+ currents in specific neuronal populations.
- DPP6-E resolves discrepancies between reconstituted and native Kv4 channel properties.
- This finding contributes to understanding the molecular basis for the diversity of A-type K+ currents in the brain.
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