Mn2+ transport by Ca2+-ATPase of sarcoplasmic reticulum

Shin Ichiro Yonekura, Chikashi Toyoshima

    Research output: Contribution to journalArticlepeer-review

    2 Citations (Scopus)


    Ca2+-ATPase of sarcoplasmic reticulum is known to pump Mn2+ in addition to Ca2+, but whether its transport mechanism is identical to that of Ca2+ is ambiguous. To clarify, we examined, by atomic absorption spectroscopy, competition between Mn2+ and Ca2+ in active transport using vesicles of sarcoplasmic reticulum (SR). Here, we demonstrate that Ca2+-ATPase transports Ca2+ and Mn2+ concomitantly but has a much lower affinity for Mn2+ (apparent Kd ~ 0.5 mm). Stoichiometries of transported ions per ATP hydrolysed, Vmax values and activation energies are very similar. Altogether, Ca2+-ATPase appears to use the same mechanism for transporting Mn2+ as that for Ca2+.

    Original languageEnglish
    Pages (from-to)2086-2095
    Number of pages10
    JournalFEBS Letters
    Publication statusPublished - Jul 1 2016


    • Ca-ATPase
    • ion selectivity
    • ion transport

    ASJC Scopus subject areas

    • Biophysics
    • Structural Biology
    • Biochemistry
    • Molecular Biology
    • Genetics
    • Cell Biology


    Dive into the research topics of 'Mn2+ transport by Ca2+-ATPase of sarcoplasmic reticulum'. Together they form a unique fingerprint.

    Cite this