Dynamin involvement in Paramecium phagocytosis
Abstract:The role of dynamin in Paramecium phagocytosis was examined by quantitative evaluation of immunoblots and ultrastructural detection by immunogold labelling with specific anti-dynamin antibodies. Western blot analysis was performed on the subcellular fractions isolated from cells internalising latex beads or exposed to pharmacological compounds that inhibit phagocytic activity. Upon onset of phagocytosis the dynamin level was significantly increased by 30% after 5 min of bead uptake but it did not differ from the control value following 15 min exposure to latex beads. Inhibition of phagocytosis with l-propranolol (150 μM) evoked a ∼2-fold decrease in dynamin expression, whereas the effect of trifluoroperazine (20 μM) was less pronounced (14% decrease). In electron microscopic studies dynamin was localized at the phagosomal and cytopharyngeal membranes and in discoidal vesicles which are indispensable for phagosome formation. After cessation of phagocytic activity no immunogold labelling of dynamin was detected in the majority of discoidal vesicles. These observations may indicate that dynamin is involved in Paramecium phagocytosis at its initial stage.
Document Type: Research Article
Affiliations: Nencki Institute of Experimental Biology, 3 Pasteur Str., 02-093 Warsaw, Poland;, Email: firstname.lastname@example.org
Publication date: December 1, 2003