Regulatory genes in fungal secondary metabolism

Summary: This chapter focuses on the main aspects of regulation of genes involved in the fungal secondary metabolism. Fungal secondary metabolism is a critically controlled process, and the genes involved in this process are clustered on specific locations on the chromosomes. The number of gene clusters varies for different fungal species. Genes involved in the regulation of secondary metabolism are highly responsive to physico-chemical stimuli that occur as a result of environmental and cellular conditions. This chapter also discusses the various biochemical pathways and the enzymes involved in the syntheses of different classes of metabolites. Control of transcription of secondary metabolite genes occurs either due to global or pathway-specific transcription factors or as a result of chromatin mediation. The extreme interest in understanding this process has come from the vast range of products of secondary metabolism produced by fungi that have gone on to become some of the most useful pharmaceutical products. These products have proved to be extremely useful as antibacterial, anti-fungal, tyrosine kinase inhibitors and immunosuppressant agents. Furthermore, many of these products are known mycotoxins. Therefore, understanding the mechanism behind the production of these metabolites has allowed scientists to over-express the associated genes in other hosts to increase the yield of these products for industrial, pharmaceutical and medicinal purposes.