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Mitochondrial ATP synthase F 1 ‐β‐subunit is a calcium‐binding protein
Author(s) -
Hubbard Michael J.,
McHugh Nicola J.
Publication year - 1996
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 - 10.1016/0014-5793(96)00767-3
Subject(s) - atp synthase gamma subunit , atp synthase , protein subunit , biochemistry , mitochondrion , calcium , gi alpha subunit , chemistry , biology , microbiology and biotechnology , enzyme , atpase , atp hydrolysis , gene , organic chemistry
Mitochondrial ATP synthase is responsive to changes in cytosolic calcium concentration, but the regulatory mechanisms are unclear. Here we identified a major 52 kDa calcium‐binding protein in rat enamel cells as the mitochondrial ATP synthase F 1 ‐β‐subunit. The F 1 ‐β‐subunit behaved as a low affinity and moderate capacity calcium‐binding protein during comparative 45 Ca overlay analyses. Equivalent behavior was shown by the F 1 ‐β‐subunit from rat liver mitochondria, but not by the homologous F 1 ‐α‐subunit, supporting the specificity of calcium binding. Evidence that the catalytic F 1 ‐β‐subunit binds calcium specifically introduces new mechanistic possibilities for regulating ATP synthase, and thereby coordinating ATP production with demand for ATP‐fuelled calcium pump activity.