A sequence in the carboxy‐terminus of the α1C subunit important for targeting, conductance and open probability of L‐type Ca2+ channels

FEBS Letters

Groschner, Klaus²  Schindler, Hansgeorg¹  Förstner, Günter¹  Sonnleitner, Max¹  Kahr, Heike¹  Kepplinger, Klaus J.F¹  Romanin, Christoph¹  Schmidt, Thomas³  Soldatov, Nikolai M⁴ 

[1] Institute for Biophysics, University of Linz, Altenbergerstr. 69, A-4040 Linz, Austria;Institute of Pharmacology and Toxicology, University of Graz, A-8010 Graz, Austria;Department of Biophysics, Leiden University, Leiden, The Netherlands;National Institute on Aging, NIH, Baltimore, MD 21224-6825, USA

关键词: Class C-type Ca2+ channel;    Carboxyl tail;    Targeting;    Conductance;    Inactivation;    Fluorescence microscopy;    GFP-labeled α1C subunit;   

DOI  :  10.1016/S0014-5793(00)01791-9

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The role of the 80-amino acid motif 1572–1651 in the C-terminal tail of α_1C Ca²⁺ channel subunits was studied by comparing properties of the conventional α_1C,77 channel expressed in HEK-tsA201 cells to three isoforms carrying alterations in this motif. Replacement of amino acids 1572–1651 in α_1C,77 with 81 non-identical residues leading to α_1C,86 impaired membrane targeting and cluster formation of the channel. Similar to α_1C,86, substitution of its 1572–1598 (α_1C,77L) or 1595–1652 (α_1C,77K) segments into the α_1C,77 channel yielded single-channel Ba²⁺ currents with increased inactivation, reduced open probability and unitary conductance, when compared to the α_1C,77 channel. Thus, the C-terminal sequence 1572–1651 of the α_1C subunit is important for membrane targeting, permeation and open probability of L-type Ca²⁺ channels.

【 授权许可】

Unknown