Antimicrobial and immunostimulatory peptide, KLK, induces an increase in cytosolic Ca2+concentration by mobilizing Ca2+from intracellular stores

Autor: Michael C. Aichinger, Jacqueline Stadlbauer, Verena Ruprecht, Alois Sonnleitner, Julian Weghuber, Tamás Henics, Gerhard J. Schütz, Anna M. Lipp
Rok vydání: 2010
Předmět:
Zdroj: Cell Biology International. 34:1109-1112
ISSN: 1095-8355
1065-6995
DOI: 10.1042/cbi20100408
Popis: The cationic antimicrobial immunomodulatory peptide, KLK (KLKL 5 KLK), exerts profound membrane interacting properties, impacting on ultrastructure and fluidity. KLK―membrane interactions that lead to these alterations require the ability of the peptide to move into an α-helical conformation. We show that KLK induces an increase of the intracellular Ca 2+ concentration in human T24 cells. The effect of KLK is buffer-sensitive, as it is detected when HBSS buffer is used, but not with PBS. This, together with the lack of effect of the middle leucine-to-proline-substituted peptide derivative [KPK (KLKLLPLLKLK)], indicates that it is the conformational propensity rather than the net positive charge that contributes to the effect of KLK on intracellular Ca 2+ level of T24 cells. We show that, although KLK slightly stimulates Ca 2+ influx into the cell, the bulk increase of Ca 2+ levels is due to KLK-induced depletion of intracellular Ca 2+ stores. Finally, we demonstrate a KLK-induced switch of PS (phosphatidylserine) from the inner to the outer plasma membrane leaflet that contributes to the onset of early apoptotic changes in these cells.
Databáze: OpenAIRE
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