The sulfur metabolism regulator MetR is a global regulator controlling phytochrome-dependent light responses in Aspergillus nidulans

Zhenzhong Yu; Jia Gao; Olumuyiwa Igbalajobi; Marek Skoneczny; Marzena Sieńko; Agnieszka M Maciejewska; Jerzy Brzywczy; Reinhard Fischer

doi:10.1016/j.scib.2020.11.001

The sulfur metabolism regulator MetR is a global regulator controlling phytochrome-dependent light responses in Aspergillus nidulans

Sci Bull (Beijing). 2021 Mar 30;66(6):592-602. doi: 10.1016/j.scib.2020.11.001. Epub 2020 Nov 9.

Authors

Zhenzhong Yu¹, Jia Gao², Olumuyiwa Igbalajobi³, Marek Skoneczny⁴, Marzena Sieńko⁴, Agnieszka M Maciejewska⁴, Jerzy Brzywczy⁴, Reinhard Fischer⁵

Affiliations

¹ Department of Microbiology, Institute for Applied Biosciences, Karlsruhe Institute of Technology (KIT)-South Campus, Karlsruhe D-76131, Germany; Key Laboratory of Plant Immunity, Jiangsu Provincial Key Lab for Organic Solid Waste Utilization, Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, National Engineering Research Center for Organic-based Fertilizers, Nanjing Agricultural University, Nanjing 210095, China. Electronic address: yuzhenzhong@njau.edu.cn.
² Department of Microbiology, Institute for Applied Biosciences, Karlsruhe Institute of Technology (KIT)-South Campus, Karlsruhe D-76131, Germany.
³ Department of Microbiology, Institute for Applied Biosciences, Karlsruhe Institute of Technology (KIT)-South Campus, Karlsruhe D-76131, Germany; Michael Smith Laboratories, Department of Microbiology and Immunology, University of British Columbia, Vancouver, British Columbia VGT 1Z4, Canada.
⁴ Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warszawa 02-106, Poland.
⁵ Department of Microbiology, Institute for Applied Biosciences, Karlsruhe Institute of Technology (KIT)-South Campus, Karlsruhe D-76131, Germany. Electronic address: reinhard.fischer@kit.edu.

PMID: 36654429
DOI: 10.1016/j.scib.2020.11.001

Abstract

Phytochrome-dependent light signaling has been studied in several fungi. In Aspergillus nidulans light-stimulated phytochrome activates the high-osmolarity glycerol (HOG) signaling pathway and thereby controls the expression of a large number of genes, many of which are related to stress responses. In a genome-wide expression analysis in A. nidulans we found that phytochrome, fphA, is under strict expression control of the central regulator of the sulfur-starvation response, MetR. This transcriptional regulator is required for the expression of genes involved in inorganic sulfur assimilation. In the presence of organic sulfur, MetR is probably ubiquitinated and possibly degraded and the transcription of sulfur-assimilation genes, e.g., sulfate permease, is turned off. The expression analysis described here revealed, however, that MetR additionally controls the expression of hundreds of genes, many of which are required for secondary metabolite production. We also show that metR mutation phenocopies fphA deletion, and five other histidine-hybrid kinases are down-regulated in the metR1 mutant. Furthermore, we found that light and phytochrome regulate the expression of at least three carbon-sulfur hydrolases. This work is a further step towards understanding the interplay between light sensing and metabolic pathways.

Keywords: Cys3; Met4; Phytochrome; Sulfur metabolism; Transcriptome.