Host protein interactions with hAT transposable elements and transposases

Hermes, a hAT (hobo, Ac and Tam3) family element, has been utilized successfully to transform a wide range of insects. Hermes moves by a canonical cut and paste mechanism in Drosophila and in the somatic cells of mosquitoes, whereas it moves by a non-canonical cut and paste mechanism in the germline of mosquitoes. This variation raises the possibility of host involvement in regulating Hermes transposition. Hence, it is important to study what factors influence its transposition. Understanding the interaction between host proteins and the transposon will further aid in understanding the behavior of hAT transposons and their mobility within the host.; The research in this dissertation will provide a better understanding on how host proteins interact with the Hermes and Herves transposons and regulate their transposition. The interaction of host proteins from Drosophila melanogaster, Aedes aegypti and Anopheles gambiae cell lines was observed with Hermes and Herves. Based on the role of HMGB proteins in Sleeping Beauty transposition, DSP1, an HMGB protein from D. melanogaster, was also tested to analyze its role in Hermes transposition. Finally, yeast one hybrid assays were performed to isolate and identify host proteins that interact with these insect hAT elements, while yeast two hybrid analysis was performed to isolate host proteins that interact with the Hermes transposase.; Gel shift assays were performed using S2, Aag2 and MOS55 insect cell line nuclear extracts to see if host proteins from Drosophila and mosquitoes specifically interacted with the Hermes and Herves elements. The assays located the regions of the Hermes and Herves ends to which host proteins interact. There was also a difference in the binding of host proteins to the two related transposons Hermes and Herves, as well as among D. melanogaster, Ae. aegypti and An. gambiae. DSP1, an HMGB protein from Drosophila was bound by the Hermes left end and it decreased Hermes transposition in vitro. Choline kinase was identified to interact with the Herves and Hermes transposons and it may possibly be involved in target interactions of Hermes. SNAIL, a transcriptional factor, was also identified to interact with the Hermes left end, however it was not involved in Hermes transposase expression and transposition.