CACANA1A mutations causing episodic and progressive ataxia alter channel trafficking and kinetics

J. Wan, Rajesh Khanna, M. Sandusky, D. M. Papazian, J. C. Jen, R. W. Baloh

Research output: Contribution to journalArticle

43 Citations (Scopus)

Abstract

Background: CACNA1A encodes Cav2.1, the pore-forming subunit of P/Q-type voltage-gated calcium channel complexes. Mutations in CACNA1A cause a wide range of neurologic disturbances variably associated with cerebellar degeneration. Functional studies to date focus on electrophysiologic defects that do not adequately explain the phenotypic findings. Objective: To investigate whether some missense mutations might interfere with protein folding and trafficking, eventually leading to protein aggregation and neuronal injury. Methods: The authors studied the functional consequences of two pore missense mutations, C287Y and G293R, in two families with EA2, one newly discovered and the other previously reported. Both mutations caused episodic and interictal ataxia. The biophysical properties of mutant and wild type calcium channels were examined by whole-cell patch-clamp recordings in transfected COS-7 cells. The plasma membrane targeting was visualized by confocal fluorescence imaging on Cav2.1 tagged with green fluorescent protein. Results: The mutant channels exhibited a marked reduction in current expression and deficiencies in plasma membrane targeting. Conclusions: In addition to altered channel function, the deficiency in protein misfolding and trafficking associated with the C287Y and G293R mutants may contribute to the slowly progressive cerebellar ataxia.

Original languageEnglish (US)
Pages (from-to)2090-2097
Number of pages8
JournalNeurology
Volume64
Issue number12
DOIs
StatePublished - Jun 28 2005
Externally publishedYes

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Protein Transport
Missense Mutation
Calcium Channels
Cell Membrane
Cerebellar Ataxia
Mutation
COS Cells
Optical Imaging
Protein Folding
Green Fluorescent Proteins
Nervous System
Wounds and Injuries
Proteins
voltage-dependent calcium channel (P-Q type)
Episodic Ataxia

ASJC Scopus subject areas

  • Neuroscience(all)

Cite this

CACANA1A mutations causing episodic and progressive ataxia alter channel trafficking and kinetics. / Wan, J.; Khanna, Rajesh; Sandusky, M.; Papazian, D. M.; Jen, J. C.; Baloh, R. W.

In: Neurology, Vol. 64, No. 12, 28.06.2005, p. 2090-2097.

Research output: Contribution to journalArticle

Wan, J. ; Khanna, Rajesh ; Sandusky, M. ; Papazian, D. M. ; Jen, J. C. ; Baloh, R. W. / CACANA1A mutations causing episodic and progressive ataxia alter channel trafficking and kinetics. In: Neurology. 2005 ; Vol. 64, No. 12. pp. 2090-2097.
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AU - Jen, J. C.

AU - Baloh, R. W.

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