Neurochemical Research

, Volume 33, Issue 10, pp 2078–2084 | Cite as

Enhanced Trafficking of Tetrameric Kv4.3 Channels by KChIP1 Clamping

  • Yuan Yuan Cui
  • Ping Liang
  • Ke Wei Wang
Original Paper


The cytoplamsic auxiliary KChIPs modulate surface expression and gating properties of Kv4 channels. Recent co-crystal structure of Kv4.3 N-terminus and KChIP1 reveals a clamping action of the complex in which a single KChIP1 molecule laterally binds two neighboring Kv4.3 N-termini at different locations, thus forming two contact interfaces involved in the protein–protein interaction. In the second interface, it functions to stabilize the tetrameric assembly, but the role it plays in channel trafficking remains elusive. In this study, we examined the effects of KChIP1 on Kv4 protein trafficking in COS-7 cells expressing EGFP-tagged Kv4.3 channels using confocal microscopy. Mutations either in KChIP1 (KChIP1 L39E-Y57A-K61A) or Kv4.3 (Kv4.3 E70A-F73E) that disrupt the protein–protein interaction within the second interface can reduce surface expression of Kv4 channel proteins. Kv4.3 C110A, the Zn2+ binding site mutation in T1 domain, that disrupts the tetrameric assembly of the channels can be rescued by WT KChIP1, but not the KChIP1 triple mutant. These results were further confirmed by whole cell current recordings in oocytes. Our findings show that key residues of second interface involved in stabilizing tetrameric assembly can regulate the channel trafficking, indicating an intrinsic link between tetrameric assembly and channel trafficking. The results also suggest that formation of octameric Kv4 and KChIP complex by KChIPs clamping takes place before their trafficking to final destination on the cell surface.


KChIP1 Kv4.3 T1 zinc binding site Trafficking Tetrameric assembly 



We thank Yanhua Huang and Yanxin Lu for their technical assistance for this work and Hao Chen for helpful discussion on the manuscript. The preparation of this manuscript was supported by research grants from the National Science Foundation of China, 30630017 and the Ministry of Science Technology of China, 2006AA02Z183 and 2007CB512100 to KWW.


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Copyright information

© Springer Science+Business Media, LLC 2008

Authors and Affiliations

  1. 1.Neuroscience Research Institute and Department of Neurobiology, Key Laboratory for Neuroscience of the Ministry of EducationCenter for Protein Sciences, Peking University Health Science CenterBeijingChina

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