Influence of Cmr1 in the Regulation of Antioxidant Function Melanin Biosynthesis in Aureobasidium pullulans

We have successfully identified the transcription factor Cmr1 from the fungus Aureobasidium pullulans Hit-lcy3T, which regulates melanin biosynthesis genes. Bioinformatics analysis revealed that the Cmr1 gene encodes a protein of 945 amino acids, containing two Cys(2)His(2) zinc finger domains and a Zn(II)(2)Cys(6) binuclear cluster domain located at the N-terminus of Cmr1. To investigate the function of the Cmr1 gene, we performed gene knockout and overexpression experiments. Our results showed that Cmr1 is a key regulator of melanin synthesis in Hit-lcy3(T), and its absence caused developmental defects. Conversely, overexpression of Cmr1 significantly increased the number of chlamydospores in Hit-lcy3(T) and improved melanin production. RT-qPCR analysis further revealed that overexpression of Cmr1 enhanced the expression of several genes involved in melanin biosynthesis, including Cmr1, PKS, SCD1, and THR1. Melanin extracted from the Hit-lcy3(T) was characterized using UV and IR spectroscopy. Furthermore, we assessed the antioxidant properties of Hit-lcy3(T) melanin and found that it possesses strong scavenging activity against DPPH center dot, ABTS center dot, and OH center dot, but weaker activity against O-2(-). These findings suggest that Hit-lcy3(T) melanin holds promise for future development as a functional food additive.

Automated summary

We have identified the transcription factor Cmr1 from the fungus Aureobasidium pullulans Hit-lcy3T, which regulates melanin biosynthesis genes. Gene knockout and overexpression experiments showed that Cmr1 is a key regulator of melanin synthesis in Hit-lcy3(T), and overexpression of Cmr1 enhanced melanin production and the expression of genes involved in melanin biosynthesis. The melanin extracted from Hit-lcy3(T) exhibited antioxidant properties and holds promise as a functional food additive.