ABSTRACT
Regulation of transcription is a critically important process that controls development, differentiation, and the maintenance of cellular homeostasis. Cells have evolved numerous mechanisms to keep gene transcription tightly in check, some of which involve the ubiquitin-proteasome system. In this chapter, we review evidence supporting the concept that ubiquitin and the proteasome not only control transcription, but provide the biochemical means to drive key steps in the transcription process forward.
Subject(s)
Proteasome Endopeptidase Complex/metabolism , Transcription, Genetic/genetics , Ubiquitin/metabolism , Animals , Humans , Neoplasms/genetics , Neoplasms/metabolism , Proteasome Endopeptidase Complex/genetics , Transcription Factors/metabolism , Ubiquitin/geneticsABSTRACT
DSP1 is an HMG-box protein which has been implicated in the regulation of homeotic genes in Drosophila melanogaster. Here we report that DSP1 is also involved in the regulation of the kni gap gene. Analysis of the phenotype of a null mutation of dsp1 (dsp1(1)) reveals that the absence of maternal DSP1 results in A4 segmentation defects that are correlated with a diminution of the kni expression domain. Genetic interaction studies demonstrate that a bcd mutation enhances the A4 defect of dsp1(1). We present in vitro and in vivo evidences for a direct interaction between DSP1 and Bicoid, mediated by the BCD homeodomain and the HMG box of DSP1. Finally, we show by immunoprecipitation of cross-linked chromatin the association of DSP1 with the kni-regulating region and discuss the potential mechanism of DSP1-mediated activation of kni.
