Back
Acta Physiologica 2009; Volume 195, Supplement 669
The 88th Annual Meeting of The German Physiological Society
3/22/2009-3/25/2009
Giessen, Germany
SPHINGOSINE-1-PHOSPHATE RECEPTORS STIMULATE MACROPHAGE PLASMA MEMBRANE ACTIN ASSEMBLY VIA ADP RELEASE, ATP SYNTHESIS AND P2X7 RECEPTOR ACTIVATION
Abstract number: O133
Markwardt1 F., Kuhnel2 M. P., Reiss2 M., Anand2 P. K., Trede2 I., Holzer2 D., Hoffmann2 E., Klapperstuck1 M., Steinberg3 T. H., Griffiths2 G.
1Julius-Bernstein-Institut fr Physiologie, Halle/Saale
2EMBL, Heidelberg
3Washington University School of Medicine, St. Louis, United States of America
Eukaryotic plasma membranes assemble actin filaments within seconds following activation of many receptors, especially during chemotaxis. Here, serum or sphingosine-1-phosphate stimulation of J774 and RAW macrophages released ADP within seconds into the extracellular medium along with an adenylate kinase activity that converted ADP to ATP. ATP then activated the P2X7 receptor (P2X7R) that was necessary for a peak of plasma membrane actin assembly within 510 sec in P2X7R expressing J774, RAW and primary macrophages. Neither actin assembly nor characteristic P2X7R channel activity was seen in response to ATP in P2X7R knockout macrophages, as detected by patch clamp analysis. Since P2X7R has been shown previously to form a macro-molecular complex with actin we propose that it is involved in the membrane assembly of actin. Our data reveal a surprisingly rapid and complex relay of signaling and externalization events that precede and control actin assembly induced by S1P.
To cite this abstract, please use the following information:
Acta Physiologica 2009; Volume 195, Supplement 669 :O133