Carl Wu's group has maintained a focus on gene regulation and chromatin structure, with emphasis on the molecular analysis of transcription factors regulating the heat shock protein (hsp) genes. This group has expanded its efforts in the heat stress signal transduction pathway, in order to capitalize on major advances made over the past year, which included the definition of a novel regulatory domain for the heat shock transcript ion factor HSF, and the demonstration that the cellular environment plays a critical role in modulating the heat shock-dependent trimerization of HSF. The completion of these projects was celebrated by publications in Science and Nature. During this year studies on crucial post-translational modifications of HSF that are induced by heat shock were initiated using mass spectrometry, the most powerful technique currently available for this purpose. Investigations on the role of chromatin structure on heat shock gene expression were also continued by in vitro reconstitution techniques, and preliminary findings on the ability of the GAGA factor to specifically disrupt nucleosomes on the hsp70 promoter were positive. If confirmed by additional studies, this finding may open a new area of research in transcription factor-chromatin interactions with broad significance for gene regulation.
