Evidence of cAMP involvement in cellobiohydrolase expression and secretion by Trichoderma reesei in presence of the inducer sophorose

BMC Microbiology

Research Article

Roberto Nascimento Silva¹  Renato Graciano de Paula¹  Karoline Maria Vieira Nogueira¹  Mariana do Nascimento Costa¹  Flávia Costa Mendonça-Natividade²  Rafael Ricci-Azevedo² 

[1] Department of Biochemistry and Immunology, Ribeirão Preto Medical School, University of São Paulo, 14049-900, Ribeirão Preto, SP, Brazil;Department of Cell Biology and Molecular and Pathogenic Bioagents, Ribeirão Preto Medical School, University of São Paulo, 14049-900, Ribeirão Preto, SP, Brazil;

关键词: Carbon source;    Cellulases;    Saprophytic fungus;    Secondary messenger;    Signaling pathways;   

DOI  :  10.1186/s12866-015-0536-z

 received in 2015-07-30, accepted in 2015-09-25,  发布年份 2015

来源: Springer

【 摘 要 】

BackgroundThe signaling second messenger cyclic AMP (cAMP) regulates many aspects of cellular function in all organisms. Previous studies have suggested a role for cAMP in the regulation of gene expression of cellulolytic enzymes in Trichoderma reesei (anamorph of Hypocrea jecorina).MethodsThe effects of cAMP in T. reesei were analyzed through both activity and expression of cellulase, intracellular cAMP level measurement, western blotting, indirect immunofluorescence and confocal microscopy.ResultsTo elucidate the involvement of cAMP in the cellulase expression, we analyzed the growth of the mutant strain ∆acy1 and its parental strain QM9414 in the presence of the inducers cellulose, cellobiose, lactose, or sophorose, and the repressor glucose. Our results indicated that cAMP regulates the expression of cellulase in a carbon source-dependent manner. The expression cel7a, and cel6a genes was higher in the presence of sophorose than in the presence of cellulose, lactose, cellobiose, or glucose. Moreover, intracellular levels of cAMP were up to four times higher in the presence of sophorose compared to other carbon sources. Concomitantly, our immunofluorescence microscopy and western blot data suggest that in the presence of sophorose, cAMP may regulate secretion of cellulolytic enzymes in T. reesei.ConclusionsThese results allow us to better understand the role of cAMP and expand our knowledge on the signal transduction pathways involved in the regulation of cellulase expression in T. reesei. Finally, our data may help develop new strategies to improve the expression of cel7a and cel6a genes, and therefore, favor their application in several biotechnology fields.

【 授权许可】

CC BY   
© Nogueira et al. 2015