Regulation of inter- and intramolecular interaction of RNA, DNA, and proteins by MLE.

Drosophila maleless (MLE) is a member of helicase superfamily 2 and functions as a dosage compensation factor essential for the development of male flies. This function provides a good opportunity to investigate diverse biochemical activities associated with MLE in the context of a defined in vivo pathway, i.e., the transcriptional activation of X-linked genes. We have shown for the first time that MLE catalyzes the unwinding of both DNA and RNA and that MLE helicase activity is essential for its in vivo function. Also, we have provided evidence that MLE stimulates the transcriptional activity of roX2 on the X chromosome. We have also found that MLE interacts with dsDNA, topoisomerase II, and nucleosome. This observation supports a current model of dosage compensation: transcriptional activation of X-linked genes is causally associated with conformational change in the male X chromosome, subsequent to the targeted association of the dosage compensation complex (DCC).