Cystathionine Gamma-Lyase Regulate Psilocybin Biosynthesis in Gymnopilus dilepis Mushroom via Amino Acid Metabolism Pathways

Psilocybin content in the fungus Gymnopilus dilepis is regulated by cysteine and methionine metabolism. Treating mycelia with S-adenosyl-l-homocysteine significantly reduced psilocybin levels, while the stipe contained more psilocybin than the pileus. Transcriptome analysis linked differential gene expression to cysteine and methionine pathways, with Cystathionine gamma-lyase (CTH) transcription positively correlating with psilocybin content. Adding a CTH inhibitor lowered psilocybin and L-serine; supplementing L-cysteine restored both, suggesting L-cysteine or CTH positively regulates psilocybin synthesis via L-serine and 4-hydroxy-L-tryptophan. This reveals a new molecular mechanism for psilocybin biosynthesis.

Study at a glance

Abstract

As a potential medicine for the treatment of depression, psilocybin has gradually attracted attention. To elucidate the molecular mechanism regulating psilocybin synthesis in Gymnopilus dilepis, ultra-performance liquid chromatography (UPLC) was used to detect the changes in psilocybin content after S-adenosyl-l-homocysteine (SAH) treatment and the changes of psilocybin content in different parts (stipe and pileus), and RNA-Seq was used to explore the mechanism of psilocybin content changes. In this study, the psilocybin content in G. dilepis mycelia treated with SAH was significantly lower than that in the control group, and the content of psilocybin in the stipe was significantly higher than that in the pileus. Transcriptome analysis revealed that differential expression genes (DEGs) were associated with cysteine and methionine metabolism. In particular, the transcription levels of genes encoding Cystathionine gamma-lyase (CTH) in different treatments and different parts were positively correlated with psilocybin content. In addition, we found that the exogenous addition of CTH activity inhibitor (DL-propargylglycine, PAG) could reduce the content of psilocybin and L-serine, and the content of psilocybin and L-serine returned to normal levels after L-cysteine supplementation, suggesting that psilocybin synthesis may be positively correlated with L-cysteine or CTH, and L-cysteine regulates the synthesis of psilocybin by affecting L-serine and 4-hydroxy-L-tryptophan. In conclusion, this study revealed a new molecular mechanism that affects psilocybin biosynthesis, which can provide a theoretical basis for improving psilocybin synthesis and the possibility for the development of biomedicine.