Date of Award


Publication Type

Master Thesis

Degree Name



Chemistry and Biochemistry

First Advisor

Sirinart Ananvoranich


Biological sciences, Dead-box RNA helicase, mRNA regulation, Stress granules, Toxoplasma gondii




RNA helicases are vital components of various pathways for post-transcriptional gene regulation. TgHoDI is a newly identified member of the DEAD-box RNA helicase family in Toxoplasma gondii. This study was aimed at characterizing the function of TgHoDI in post-transcriptional regulation during various stages of the parasite life cycle. Through immunofluorescence analyses, TgHoDI was found to colocalize with mRNA aggregates in cytoplasmic foci. Furthermore, colocalization studies of TgHoDI with PABPC3 identified these proteins as components of RNA aggregates known as stress granules. Cycloheximide and arsenite treatment of extracellular parasites revealed the presence of mechanisms involved in the determination of mRNA fate in Toxoplasma. Also, TgHoDI was found to functionally compliment the temperature sensitive phenotype in Δdhh1 yeast, validating its role in stress response. These findings confirm that TgHoDI is a vital component in the formation of stress granules and possibly involved in the mechanisms of post-transcriptional gene regulation.