Alterations in the protein pattern of subcellular fractions isolated from Paramecium cells suppressed in phagocytosis.
SDS-PAGE and quantitative densitometric analysis revealed alterations in the protein pattern of subcellular fractions (100,000 x g) isolated from Paramecium aurelia (299s axenic) cells suppressed in phagocytosis as compared with the control. Two different agents were used to block phagocytosis: the beta-adrenergic antagonist-1-propranolol (200 microM) and inhibitor of calmodulin-dependent processes--trifluoperazine (20 microM). More than 40 polypeptides were identified in the cytosolic (soluble) fractions S1 and S2. A considerable decrease in band intensity was found for three polypeptides: by 60% for 87 kDa band, 52% for 75 kDa and 37% for 42 kDa in comparison to the control, when S2 fractions from propranolol-treated cells of equal load were quantified. TFP treatment evoked only a small decrease in the intensity of the same bands: 9%, 10% and 6%, respectively. The 42 kDa band was identified by Western blot analysis and chemiluminiscent detection to be actin. This result suggests that actin may be a primary target of pharmacological agents used in this study to inhibit Paramecium phagocytic activity.
Surmacz
L
L
Department of Cell Biology, Nencki Institute of Experimental Biology, Warsaw, Poland.
Wiejak
J
J
Wyroba
E
E
D000199:Actins / Q000032:analysis*; D000319:Adrenergic beta-Antagonists / Q000494:pharmacology; D000818:Animals; D003720:Densitometry; D004591:Electrophoresis, Polyacrylamide Gel; D010247:Paramecium / Q000737:chemistry* / Q000187:drug effects / Q000648:ultrastructure; D010587:Phagocytosis / Q000187:drug effects*; D011433:Propranolol / Q000494:pharmacology; D015800:Protozoan Proteins / Q000032:analysis*; D013347:Subcellular Fractions; D014268:Trifluoperazine / Q000494:pharmacology
D000199:Actins; D000319:Adrenergic beta-Antagonists; D015800:Protozoan Proteins; D014268:Trifluoperazine; D011433:Propranolol