Identification and characterization of alternative splice variants of the mouse Trek2/Kcnk10 gene

Area of Science:

• Neuroscience
• Molecular Biology
• Ion Channel Research

Background:

• Two-pore domain potassium (K(2P)) channels, specifically the Trek subfamily (Trek1/Kcnk2, Trek2/Kcnk10), are crucial for background potassium conductances and are implicated in neurological functions.
• While Trek1's diversity arises from alternative translation and splicing, Trek2's post-transcriptional regulation remains largely uncharacterized.

Purpose of the Study:

• To investigate the impact of post-transcriptional modifications on the expression and function of the Trek2 channel.
• To characterize novel splice isoforms of the mouse Trek2 gene and their functional consequences.

Main Methods:

• Identification and characterization of novel mouse Trek2 splice isoforms (Trek2-1p and Trek2b).
• Analysis of Trek2 variant expression patterns in the mouse central nervous system (CNS).
• Heterologous expression of Trek2 isoforms in HEK 293 cells to assess functional currents and plasma membrane localization.

Main Results:

• Two novel Trek2 splice variants, a truncated Trek2-1p and an amino-terminally altered Trek2b, were identified with prominent CNS expression.
• Trek2-1p expression did not yield novel whole-cell currents.
• Trek2b expression resulted in significantly larger K(+) currents (~fivefold) compared to Trek2a and Trek2c, correlating with increased plasma membrane levels.

Conclusions:

• The study reveals molecular diversity within the Trek2 channel subfamily through novel splice isoforms.
• The amino terminus of Trek2b plays a critical role in enhancing channel trafficking and/or stability, leading to increased K(+) currents.
• These findings provide new insights into the regulation of K(2P) channel function and neuronal excitability.