PRMT5 promotes cellulase production by regulating the expression of cellulase gene eg2 through histone methylation in Ganoderma lucidum.

Background: Cellulase can degrade cellulose into reducing sugar, participating in the natural carbon cycle. Simultaneously, cellulase enhances the efficiency and quality of industrial production while also demonstrating significant potential in environmental protection and bioenergy development. Ganoderma lucidum, as a white rot fungus, secret a large amount of cellulase during growth. It is reported that some post-translational modification affects cellulase production. Protein arginine methyltransferase 5 (PRMT5) is involved in transcriptional regulation, RNA processing and signal transduction of biological processes. Therefore, this study primarily investigated whether and how PRMT5 was involved in the regulation of cellulase production in G. lucidum.

Results: Our study found that silencing prmt5 reduced the activity of cellulase by 23%, and the growth rate of G. lucidum mycelium in wood chip tube by approximately 71%. The degradation of agricultural waste corn straw and corn cob decreased by approximately 60% and 51%, respectively. These results suggest that PRMT5 may promote cellulase production in G. lucidum. Through ChIP-qPCR, we found that PRMT5 could positively regulate the expression of endoglucanase 2 (eg2) through histone methylation, and further study on the construction of eg2 silencing and overexpression strains showed that the expression of eg2 promoted cellulase activity.

Conclusions: Taken together, our results suggest that PRMT5 in G. lucidum promotes cellulase production by regulating the expression of cellulase gene eg2 through histone methylation.