Yeast, Paramecium and mammal cells use many of the same proteins to carry out exocytosis for example SNARE, Syntaxin and SNAP 25 proteins are present in all three systems. One major protein involved in exocytosis is protein phosphatase type 1 (PP1). Kissmehl et al., (1996) used okadaic acid to inhibit PP1 in Paramecium and found that unlike other species, PP1 did not have a significant role in exocytosis. However these results are complicated since the use of Okadaic acid on Paramecium has been shown to have possible side effects such as affecting membrane permeability. In order to verify the results from the Kissmehl et al., (1996) and Momayezi et al., (1996) experiments, RNA interference (RNAi) was used to silence PP1 in Paramecium. The amount of trichocyst discharged was measured and compared between treatments. Our results using RNAi supported the results of the Okadaic acid experiments, concluding that PP1 may not have a significant role in exocytosis in Paramecium, unlike as seen in mammal and yeast cells.


Fraga, Dean



Publication Date


Degree Granted

Bachelor of Arts

Document Type

Senior Independent Study Thesis



© Copyright 2007 Jeff Winkler