TY - JOUR
T1 - Effect of cell wall integrity stress and RlmA transcription factor on asexual development and autolysis in Aspergillus nidulans
AU - Kovács, Zsuzsanna
AU - Szarka, Máté
AU - Kovács, Szilvia
AU - Boczonádi, Imre
AU - Emri, Tamás
AU - Abe, Keietsu
AU - Pócsi, István
AU - Pusztahelyi, Tünde
N1 - Funding Information:
The Authors are indebted to the Cell Biology Work Group of the Department of Microbial Biotechnology and Cell Biology for the microscopic work. TP also thanks Ms. Melinda Takács and Mrs. Lászlóné Gábor Tóth for their technical assistance. This project was supported financially by the TÁMOP 4.2.1./B-09/1/KONV-2010-0007 project, which is co-financed by the European Union and the European Social Fund.
PY - 2013/5
Y1 - 2013/5
N2 - The cell wall integrity (CWI) signaling pathway is responsible for cell wall remodeling and reinforcement upon cell wall stress, which is proposed to be universal in fungal cultures. In Aspergillus nidulans, both the deletion of rlmA encoding the RlmA transcription factor in CWI signaling and low concentrations of the cell wall polymer intercalating agent Congo Red caused significant physiological changes. The gene deletion mutant Δ. rlmA strain showed decreased CWI and oxidative stress resistances, which indicated the connection between the CWI pathway and the oxidative stress response system. The Congo Red stress resulted in alterations in the cell wall polymer composition in submerged cultures due to the induction of the biosynthesis of the alkali soluble fraction as well as the hydrolysis of cell wall biopolymers. Both RlmA and RlmA-independent factors induced by Congo Red stress regulated the expression of glucanase (ANID_00245, engA) and chitinase (chiB, chiA) genes, which promoted the autolysis of the cultures and also modulated the pellet sizes. CWI stress and rlmA deletion affected the expression of brlA encoding the early conidiophore development regulator transcription factor BrlA and, as a consequence, the formation of conidiophores was significantly changed in submerged cultures. Interestingly, the number of conidiospores increased in surface cultures of the Δ. rlmA strain. The in silico analysis of genes putatively regulated by RlmA and the CWI transcription factors AnSwi4/AnSwi6 in the SBF complex revealed only a few jointly regulated genes, including ugmA and srrA coding for UgmA UDP-galactopyranose mutase and SrrA stress response regulator, respectively.
AB - The cell wall integrity (CWI) signaling pathway is responsible for cell wall remodeling and reinforcement upon cell wall stress, which is proposed to be universal in fungal cultures. In Aspergillus nidulans, both the deletion of rlmA encoding the RlmA transcription factor in CWI signaling and low concentrations of the cell wall polymer intercalating agent Congo Red caused significant physiological changes. The gene deletion mutant Δ. rlmA strain showed decreased CWI and oxidative stress resistances, which indicated the connection between the CWI pathway and the oxidative stress response system. The Congo Red stress resulted in alterations in the cell wall polymer composition in submerged cultures due to the induction of the biosynthesis of the alkali soluble fraction as well as the hydrolysis of cell wall biopolymers. Both RlmA and RlmA-independent factors induced by Congo Red stress regulated the expression of glucanase (ANID_00245, engA) and chitinase (chiB, chiA) genes, which promoted the autolysis of the cultures and also modulated the pellet sizes. CWI stress and rlmA deletion affected the expression of brlA encoding the early conidiophore development regulator transcription factor BrlA and, as a consequence, the formation of conidiophores was significantly changed in submerged cultures. Interestingly, the number of conidiospores increased in surface cultures of the Δ. rlmA strain. The in silico analysis of genes putatively regulated by RlmA and the CWI transcription factors AnSwi4/AnSwi6 in the SBF complex revealed only a few jointly regulated genes, including ugmA and srrA coding for UgmA UDP-galactopyranose mutase and SrrA stress response regulator, respectively.
KW - Aspergillus nidulans
KW - Autolysis
KW - Cell wall
KW - Cell wall integrity
KW - Conidiophore
KW - Oxidative stress
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U2 - 10.1016/j.fgb.2013.02.004
DO - 10.1016/j.fgb.2013.02.004
M3 - Article
C2 - 23485399
AN - SCOPUS:84877050409
VL - 54
SP - 1
EP - 14
JO - Fungal Genetics and Biology
JF - Fungal Genetics and Biology
SN - 1087-1845
ER -