The COP9 signalosome mediates transcriptional and metabolic response for hormones, oxidative stress protection and cell wall rearrangement during fungal development

Krystyna Nahlik (1) , Marc Dumkow (1) , Özgür Bayram (1) , Kerstin Helmstaedt (1) , Silke Busch (1) , Oliver Valerius (1) , Jennifer Gerke (1) , Michael Hoppert (2) , Elke Schwier (1) , Lennart Opitz (3) , Mieke Westermann (4) , Stephanie Grond (4) , Kirstin Feussner (1) , Cornelia Goebel (5) , Alexander Kaever (3) , Peter Meinecke (3) , Ivo Feussner (5) , Gerhard H Braus (6)

1 Molecular Microbiology & Genetics
2 Microbiology
3 Centre for Statistics
4 Institut für Organische und Biomolekulare Chemie
5 Albrecht-von-Haller Institut für Pflanzenwissenschaften
6 Molecular Microbiology & Genetics

The COP9 signalosome complex (CSN) is a crucial regulator of ubiquitin ligases. Defects in CSN result in embryonic impairment and death in higher eukaryotes, whereas the filamentous fungus Aspergillus nidulans survives without CSN, but is unable to complete sexual development. We investigated overall impact of CSN activity on A. nidulans cells by combined transcriptome, proteome and metabolome analysis. Absence of csn5/csnE affects transcription of at least 15 % of genes during development, including numerous oxidoreductases. csnE deletion leads to changes in the fungal proteome indicating impaired redox regulation and hypersensitivity to oxidative stress. CSN promotes the formation of asexual spores by regulating developmental hormones produced by PpoA and PpoC dioxygenases. We identify more than 100 metabolites, including orsellinic acid derivatives, accumulating preferentially in the csnE mutant. We also show that CSN is required to activate glucanases and other cell wall recycling enzymes during development. These findings suggest a dual role for CSN during development: it is required early for protection against oxidative stress and hormone regulation and is later essential for control of the secondary metabolism and cell wall rearrangement.

Mots clés: Life Sciences

Krystyna Nahlik, Marc Dumkow, Özgür Bayram, Kerstin Helmstaedt, Silke Busch, et al.. The COP9 signalosome mediates transcriptional and metabolic response for hormones, oxidative stress protection and cell wall rearrangement during fungal development. Molecular Microbiology, 2010, 78 (4), pp.964. ⟨10.1111/j.1365-2958.2010.07384.x⟩. ⟨hal-00580344⟩