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

Westerink, R.H.S. and Rook, M.B. and Beekwilder, J.P. and Wadman, W.J. (2006) Dual role of calbindin-D28K in vesicular catecholamine release from mouse chromaffin cells. Journal of Neurochemistry, 99 (2). pp. 628-640. ISSN 0022-3042

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Abstract:	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.
Item Type:	Article
Copyright:	© 2006 Wiley InterScience
Faculty:	Electrical Engineering, Mathematics and Computer Science (EEMCS)
Research Group:	Biomedical Signals and Systems (BSS)
Link to this item:	http://purl.utwente.nl/publications/63766
Official URL:	http://dx.doi.org/10.1111/j.1471-4159.2006.04099.x
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