A thorough genetic, physiological and molecular characterisation of the genes involved in three pathways of nitrogen utilisation in the fungus Aspergillus nidulans has already been achieved. This has included the sequencing of all regulatory and many of the structural genes concerned with thes pathways. This proposal seeks to dissect, through mutational analysis,
the functional domains of each of the regulatory genes and to establish the possible interactions between the protein encoded by the wide domain regulatory gene area, mediating nitrogen metabolite repression (and thus ensuring preferential utilisation of favoured nitrogen sources), and those
encoded by the specific regulatory genes for each pathway, mediating induction by respective substrates. Moreover, this analysis might shed light on the interactions between these transcription factors and more general components of the transcriptional apparatus.
While the objectives of this proposal relate only to fundamental science, the understanding of the utilisation of nitrogen sources in a model eukaryotic microbe is of obvious practical importance. Furthermore, although this proposal aims to understand the nature of transcriptional complexes in
one model organism, the fact that the specific transcription factors belong to a class of DNA-binding proteins probably restricted to the fungi whilst the wide domain AREA proteins belongs to a group whose origin predates the divergence between fungi and metazoa will shed light on the evolution of the transcriptional apparatus.
Funding SchemeCSC - Cost-sharing contracts
W12 0HS London