Funding Source
National Science Foundation, National Institutes of Health
Grant Number
MCB-9874646, NSF MCB-0236393, SO6GM08008
Department
Department of Biology
Document Type
Article
Publication Date
9-2006
Abstract
In contrast to most primary metabolism genes, the genes involved in secondary metabolism and certain nutrient utilization pathways are clustered in fungi. Recently a nuclear protein, LaeA, was found to be required for the transcription of several secondary metabolite gene clusters in Aspergillus nidulans. Here we show that LaeA regulation does not extend to nutrient utilization or the spoC1 sporulation clusters. One of the secondary metabolite clusters regulated by LaeA contains the positive regulatory (i.e. aflR) and biosynthetic genes required for biosynthesis of sterigmatocystin (ST), a carcinogenic toxin. Analysis of ST gene cluster expression indicates LaeA regulation of the cluster is location specific as transcription of genes bordering the ST cluster are unaffected in a ΔlaeA mutant and placement of a primary metabolic gene, argB, in the ST cluster resulted in argB silencing in the ΔlaeA background. ST cluster gene expression was remediated when an additional copy of aflR was placed outside of the cluster but not when placed in the cluster. Site-specific mutation of an s-adenosyl methionine (AdoMet) binding site in LaeA generated a ΔlaeA phenotype suggesting the protein to be a methyltransferase.
Recommended Citation
Bok, J. W.; Noordermeer, D.; Ireland, Shubha Kale; and Keller, N. P., "Secondary Metabolic Gene Cluster Silencing in Aspergillus Nidulans" (2006). Faculty and Staff Publications. 181.
https://digitalcommons.xula.edu/fac_pub/181
Comments
DOI: 10.1111/j.1365-2958.2006.05330.x
PubMed ID: 16968230
Acknowledgements This research was funded by NSF Grant MCB-9874646 and NSF MCB-0236393 to N.P.K. and NIH (MBRS) Grant No. SO6GM08008 to S.P.K