Date of Award


Publication Type

Master Thesis

Degree Name



Chemistry and Biochemistry


Chemistry, Biochemistry.




RNA interference (RNAi) is an evolutionarily conserved mechanism through which double-stranded RNA (dsRNA) triggers degradation of homologous transcripts. Argonaute proteins and small interfering RNAs (siRNAs) are the known signature components of the RNAi effector complex, named RNA-induced silencing complex (RISC). Our group previously reported that dsRNA-induced specific gene silencing is functional in Toxoplasma gondii, an intracellular parasite of humans and other mammals. In the present study, we describe the characterization of the first Argonaute protein (TgAgo) in T. gondii. The cDNA clone has an open reading frame (ORF) of 1575 bp which encodes a putative 524-amino-acid protein with a calculated molecular weight of 58.5 kDa and an estimated isoelectric point (pI) of 9.4. Using bioinformatic methods, we found significant homology between the Piwi domains of TgAgo and previously reported Argonaute proteins, but were unable to locate a PAZ domain. Polyclonal antibodies raised against TgAgo peptides have recognized a protein of the expected size (58.5 kDa), which was mainly localized in the cytoplasm. (Abstract shortened by UMI.) Source: Masters Abstracts International, Volume: 44-03, page: 1366. Thesis (M.Sc.)--University of Windsor (Canada), 2005.