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Channel induction by palytoxin in yeast cells expressing Na + ,K + ‐ATPase or its chimera with sarco/endoplasmic reticulum Ca 2+ ‐ATPase
Author(s) -
Ito Katsuaki,
Toyoda Isao,
Higashiyama Masato,
Uemura Daisuke,
Sato Masa H.,
Yoshimura Shige H.,
Ishii Toshiaki,
Takeyasu Kunio
Publication year - 2003
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(03)00418-6
Subject(s) - endoplasmic reticulum , ouabain , palytoxin , chemistry , atpase , transfection , protein subunit , chimera (genetics) , microbiology and biotechnology , biochemistry , biophysics , enzyme , biology , sodium , organic chemistry , toxin , gene
Palytoxin (PTX) induces a cation channel through interaction with Na + ,K + ‐ATPase. It is unclear how this action relates to the enzyme catalytic activity. We examined whether the action of PTX depends on the catalytic domain specific for Na + ,K + ‐ATPase. Wild‐type Na + ,K + ‐ATPase α‐subunit (NNN) or its chimera (NCN), in which the catalytic domain was replaced with that of sarcoplasmic/endoplasmic reticulum Ca 2+ ‐ATPase, was co‐expressed with β‐subunit in the yeast Saccharomyces cerevisiae . PTX (0.1–100 nM) increased K + efflux in NNN‐ or NCN‐transfected cells to a similar degree but not in non‐transfected cells. When ouabain‐resistant NNN and NCN were expressed, PTX also increased K + efflux. Ouabain inhibited the effect of PTX in NNN or NCN cells but not in ouabain‐resistant cells. These data suggest that the channel‐forming action of PTX does not depend on the catalytic domain species.