Involvement of phosphatidylinositol 4,5-bisphosphate binding proteins in the generation of contractile oscillations in the Physarum polycephalum plasmodium

• Published in: Biophysics (Oxford) Vol. 59; no. 5; pp. 758 - 763
• Main Authors: Matveeva, N. B., Beylina, S. I., Klyueva, A. A., Teplov, V. A.
• Format: Journal Article
• Language: English
• Published: Moscow Pleiades Publishing 01.09.2014; Springer Nature B.V
• Subjects: Biological and Medical Physics; Biophysics; Cell Biophysics; Cellular biology; Kinases; Physarum polycephalum; Physics; Physics and Astronomy; Plasmodium; Proteins; phospholipase C; MARCKS; contractility; phosphatidylinositol 4,5-bisphosphate; plasmodium; auto-oscillations; protein kinase C
• ISSN: 0006-3509; 1555-6654
• DOI: 10.1134/S0006350914050157

Using the Physarum polycephalum plasmodium, a giant amoeboid cell with strongly pronounced auto-oscillatory mode of motility, which exhibits regularities of motile behavior common with those of tissue cells and has the same signal systems, the possibility of participation of phosphatidylinositol 4,5-bisphosphate in the regulation of contractile activity has been studied. The effect of neomycin as a substrate inhibitor of phospholipase C, which binds with high affinity to phosphatidylinositol 4,5-bisphosphate in the membrane, on force oscillations generated by plasmodial strands under isometric conditions and after the addition of protein kinase C inhibitors staurosporine, UCN-01, and Ro-318220, separately and in combination with the calmodulin inhibitor calmidazolium, has been examined. It has been shown that neomycin at pH 7.0 and concentrations of 0.1–5.0 mM stops contractile oscillations for 10–30 min but then they begin to gradually resume; the oscillation period at the initial stage of restoration is shorter than it was earlier, and then increases because of elongation of the contraction phase. Analysis of data obtained is in favor of the assumption that the plasmodial membrane contains MARCKS-like proteins and protein kinase C-controlled pools of phosphatidylinositol-4,5-bisphosphate, which can participate in the generation of auto-oscillations observed in the plasmodium.