Regulating the Function of Cubitus Interruptus, the Hedgehog Pathway Transcription Factor.

摘要

The Hedgehog (Hh) signal transduction pathway is essential for the growth and patterning of multiple tissues and organs during embryonic development in both vertebrates and invertebrates. Aberrant activation of the Hh pathway in humans drives the establishment and progression of a wide variety of tumors. In Drosophila, Hh regulates the transcription factor Cubitus interruptus (Ci) by regulating it in four manners: protein degredation, partial proteolysis into a repressor, nuclear localization and activation.;In this dissertation, I describe the utilization of Co(III) Schiff base-DNA conjugates as a versatile class of specific and potent inhibitors of zinc finger transcription factors. Using Ci as a model, through a variety of in vitro and in vivo experiments, I show conjugation of the DNA binding consensus sequence to a Co(III) Schiff base is able to specifically and irreversibly inhibit Ci. This work provides evidence that Co(III) Schiff base-DNA conjugates could be utilized as specifically tailored inhibitors for a wide variety of tumors.;This dissertation also sheds light on the poorly understood process of Ci activation. A sensitized genetic screen for novel Hh pathway members generated many interesting putative hits. My work, in collaboration with Leonard Rabinow's Laboratory, shows that the kinase Darkener of Apricot (Doa) is required for full Hh target gene expression. Doa phosphorylates Ci on Serine 199, increasing its activity but does not alter protein levels or localization. Finally, my work has shown Doa is a Hh target gene itself, placing Doa in a feed forward activation loop with Ci.