Regulation of phospholipase D activity in synaptosomes permeabilized with Staphylococcus aureus α‐toxin

FEBS Letters

Böckmann, Ira²  Klein, Jochen²  Valeva, Angela¹  von Eichel-Streiber, Christoph¹  Kempter, Ulrike²  Sarri, Elisabet²  Weichel, Oksana² 

[1] Department of Medical Microbiology and Hygiene, University of Mainz, Obere Zahlbacher Str. 67, D-55101 Mainz, Germany;Department of Pharmacology, University of Mainz, Obere Zahlbacher Str. 67, D-55101 Mainz, Germany

关键词: Synaptosome;    Phospholipase D;    Staphylococcus aureus α-toxin;    Calcium/calmodulin-dependent protein kinase II;    Rho protein;    Clostridium difficile toxin B;    BFA;    brefeldin A;    CaMKII;    calcium/calmodulin-dependent kinase II;    PEth;    phosphatidylethanol;    PKC;    protein kinase C;    PLD;    phospholipase D;    PtdCho;    phosphatidylcholine;    TcdB;    Clostridium difficile toxin B;   

DOI  :  10.1016/S0014-5793(98)01479-3

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

In order to investigate the regulation of presynaptic phospholipase D (PLD) activity by calcium and G proteins, we established a permeabilization procedure for rat cortical synaptosomes using Staphylococcus aureus α-toxin (30–100 μg/ml). In permeabilized synaptosomes, PLD activity was significantly stimulated when the concentration of free calcium was increased from 0.1 μM to 1 μM. This activation was inhibited in the presence of KN-62 (1 μM), an inhibitor of calcium/calmodulin-dependent kinase II (CaMKII), but not by the protein kinase C inhibitor, Ro 31-8220 (1–10 μM). Synaptosomal PLD activity was also stimulated in the presence of 1 μM GTPγS. When Rho proteins were inhibited by pretreatment of the synaptosomes with Clostridium difficile toxin B (TcdB; 1–10 ng/ml), the effect of GTPγS was significantly reduced; in contrast, brefeldin A (10–100 μM), an inhibitor of ARF activation, was ineffective. Calcium stimulation of PLD was inhibited by TcdB, but GTPγS-dependent activation was insensitive to KN-62. We conclude that synaptosomal PLD is activated in a pathway which sequentially involves CaMKII and Rho proteins.

【 授权许可】

Unknown