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A sequence in the carboxy‐terminus of the α 1C subunit important for targeting, conductance and open probability of L‐type Ca 2+ channels
Author(s) -
Kepplinger Klaus J.F,
Kahr Heike,
Förstner Günter,
Sonnleitner Max,
Schindler Hansgeorg,
Schmidt Thomas,
Groschner Klaus,
Soldatov Nikolai M,
Romanin Christoph
Publication year - 2000
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/s0014-5793(00)01791-9
Subject(s) - conductance , protein subunit , amino acid , chemistry , peptide sequence , hek 293 cells , biophysics , c terminus , stereochemistry , biochemistry , crystallography , biology , gene , physics , condensed matter physics
The role of the 80‐amino acid motif 1572–1651 in the C‐terminal tail of α 1C Ca 2+ 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 Ba 2+ 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 Ca 2+ channels.