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The plasma membrane Ca 2+ pump from proximal kidney tubules is exclusively localized and active in caveolae
Author(s) -
Tortelote Giovane G.,
Valverde Rafael H.F.,
Lemos Thiago,
Guilherme Adı́lson,
Einicker-Lamas Marcelo,
Vieyra Adalberto
Publication year - 2004
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/j.febslet.2004.08.055
Subject(s) - caveolae , kidney , chemistry , membrane , biophysics , plasma , biochemistry , biology , physics , endocrinology , quantum mechanics
Plasma membrane Ca 2+ ‐ATPase is involved in the fine‐tuned regulation of intracellular Ca 2+ . In this study, the presence of Ca 2+ ‐ATPase in caveolae from kidney basolateral membranes was investigated. With the use of a discontinuous sucrose gradient, we show that Ca 2+ ‐ATPase is exclusively located and fully active in caveolin‐containing microdomains. Treatment with methyl‐β‐cyclodextrin – a cholesterol chelator – leads to a spreading of both caveolin and completely inactive Ca 2+ ‐ATPase toward high‐density fractions. These data support the view that Ca 2+ fluxes mediated by Ca 2+ ‐ATPase in kidney epithelial cells occur only in caveolae, being strictly dependent on the integrity of these microdomains.