A novel DPP6 isoform (DPP6-E) can account for differences between neuronal and reconstituted A-type K channels

作者：Maffie Jonathon; Blenkinsop Timothy; Rudy Bernardo^*

来源：Neuroscience Letters, 2009, 449(3): 189-194.

DOI：10.1016/j.neulet.2008.10.098

• A-type potassium channel
• Inactivation
• DPPX
• DPP6

The channels mediating most of the somatodendritic A-type K current in neurons are thought to be ternary complexes of Kv4 pore-forming subunits and two types of auxiliary subunits, the K channel interacting proteins (KChIPs) and dipeptidyl-peptidase-like (DPPL) proteins. The channels expressed in heterologous expression systems by mixtures of Kv4.2, KChIP1 and DPP6-S resemble in many properties the A-type current in hippocampal CA1 pyramidal neurons and cerebellar granule cells, neurons with prominent A-type K currents. However, the native currents have faster kinetics. Moreover, the A-type currents in neurons in intermediary layers of the superior colliculus have even faster inactivating rates. We have characterized a new DPP6 spliced isoform, DPP6-E, that produces in heterologous cells ternary Kv4 channels with very fast kinetics. DPP6-E is selectively expressed in a few neuronal populations in brain including cerebellar granule neurons, hippocampal pyramidal cells and neurons in intermediary layers of the superior colliculus. The effects of DPP6-E explain past discrepancies between reconstituted and native Kv4 channels in some neurons, and contributes to the diversity of A-type K currents in neurons.

• 出版日期2009-1-16