Dual role of calbindin-D28K in vesicular catecholamine release from mouse chromaffin cells

R.H.S. Westerink, M.B. Rook, J.P. Beekwilder, W.J. Wadman

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    12 Citations (Scopus)


    Calbindin-D28K is suggested to play a postsynaptic role in neurotransmission and in the regulation of the intracellular Ca2+ concentration. However, it is still unclear whether calbindin- D28K has a role in the regulation of exocytosis, either as Ca2+ buffer or as Ca2+ sensor. Amperometric recordings of catecholamine exocytosis from wild-type and calbindin-D28K knockout mouse chromaffin cells reveal a strong reduction in the number of released vesicles, as well as in the amount of neurotransmitter released per fusion event in knockout cells. However, Ca2+ current recordings and Ca2+ imaging experiments, including video-rate confocal laser scanning microscopy, revealed that the intracellular Ca2+ dynamics are remarkably similar in wild-type and knockout cells. The combined results demonstrate that calbindin-D28K plays an important and dual role in exocytosis, affecting both release frequency and quantal size, apparently without strong effects on intracellular Ca2+ dynamics. Consequently, the possibility that calbindin-D28K functions not only as a Ca2+ buffer but also as a modulator of vesicular catecholamine release is discussed. Keywords: amperometry, Ca2+ dynamics, Ca2+ sensor, calcium binding proteins, exocytosis, video-rate confocal laser scanning microscopy.
    Original languageUndefined
    Article number10.1111/j.1471-4159.2006.04099.x
    Pages (from-to)628-640
    Number of pages13
    JournalJournal of neurochemistry
    Issue number06CH37725
    Publication statusPublished - 2006


    • BSS-Biomechatronics and rehabilitation technology
    • Ca2+ dynamics
    • Ca2+ sensor
    • Amperometry
    • IR-63766
    • calcium binding proteins
    • video-rate confocal laser scanning microscopy
    • EWI-8428
    • METIS-237719
    • exocytosis

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