Background: Laccases are green biocatalysts with wide industrial applications. The study of efficient and specific laccase producers remains a priority. Cerrena species have been shown to be promising basidiomycete candidates for laccase production. Although two sets of Cerrena genome data have been publicly published, no comprehensive bioinformatics study of laccase gene family in C. unicolor has been reported, particularly concerning the analysis of their three-dimensional (3D) structures and molecular docking to substrates, like ABTS and aflatoxin B₁ (AFB₁). Results: In this study, we conducted a comprehensive genome-wide analysis of laccase gene family in C. unicolor 87613. We identified eighteen laccase genes (CuLacs) and classified them into three clades using phylogenetic analysis. We characterized these laccases, including their location in contig 5,6,9,12,15,19,26,27, gene structures of different exon-intron arrangements, molecular weight ranging from 47.89 to 141.41 kDa, acidic pI value, 5–15 conserved protein motifs, signaling peptide of extracellular secretion (harbored by 13 CuLacs) and others. In addition, the analysis of cis-acting element in laccase promoters indicated that the transcription response of CuLac gene family was regulatable and complex under different environmental cues. Furthermore, analysis of transcription pattern revealed that CuLac8, 12 and CuLac2, 13 were the predominant laccases in response to copper ions or oxidative stress, respectively. Finally, we focused on the 3D structure analysis of CuLac proteins. Seven laccases with extra transmembrane domains or special sequences were particularly interesting. Predicted structures of each CuLac protein with or without these extra sequences showed altered interacting amino acid residues and binding sites, leading to varied affinities to both ABTS and AFB₁. As far as we know, it is the first time to discuss the influence of the extra sequence on laccase’s affinity to substrates. Conclusions: Our findings provide robust genetic data for a better understanding of the laccase gene family in C. unicolor 87613, and create a foundation for the molecular redesign of CuLac proteins to enhance their industrial applications.

N⁶-methyladenosine (m⁶A)-mediated epitranscriptomic regulation is critical for various physiological processes. Genetic studies demonstrate that proper m⁶A-methylation is required for mouse brain development and function. Revealing landscapes of m⁶A-methylation in the cerebral cortex at different developmental stages will help to understand the biological meaning of epitranscriptomic regulation. Here, we depict the temporal-specific m⁶A-methylation status in mouse embryonic and postnatal cortices using methylated RNA immunoprecipitation (MeRIP) sequencing. We identified unique m⁶A binding motifs in stage-specific RNAs and found that more RNA transcripts are temporally methylated in embryonic cortices than in postnatal ones. Moreover, we found that cortical transcription factors and genes associated with neurological disorders are broadly as well specifically methylated at m⁶A sites. Our study highlights the importance of epitranscriptomic regulation in the developing cortex and provides a fundamental reference for future mechanistic examinations of m⁶A methylation-mediated gene expression regulation in normal brain development and neurological disorders.

Background: White-rot fungi are known to naturally produce high quantities of laccase, which exhibit commendable stability and catalytic efficiency. However, their laccase production does not meet the demands for industrial-scale applications. To address this limitation, it is crucial to optimize the conditions for laccase production. However, the regulatory mechanisms underlying different conditions remain unclear. This knowledge gap hinders the cost-effective application of laccases. Results: In this study, we utilized transcriptomic and metabolomic data to investigate a promising laccase producer, Cerrena unicolor 87613, cultivated with fructose as the carbon source. Our comprehensive analysis of differentially expressed genes (DEGs) and differentially abundant metabolites (DAMs) aimed to identify changes in cellular processes that could affect laccase production. As a result, we discovered a complex metabolic network primarily involving carbon metabolism and amino acid metabolism, which exhibited contrasting changes between transcription and metabolic patterns. Within this network, we identified five biomarkers, including succinate, serine, methionine, glutamate and reduced glutathione, that played crucial roles in co-determining laccase production levels. Conclusions: Our study proposed a complex metabolic network and identified key biomarkers that determine the production level of laccase in the commercially promising Cerrena unicolor 87613. These findings not only shed light on the regulatory mechanisms of carbon sources in laccase production, but also provide a theoretical foundation for enhancing laccase production through strategic reprogramming of metabolic pathways, especially related to the citrate cycle and specific amino acid metabolism.

Rad6 functions as a ubiquitin-conjugating protein that regulates cellular processes in many fungal species. However, its role in filamentous entomopathogenic fungi remains poorly understood. This study characterizes Rad6 in Beauveria bassiana, a filamentous fungus widely employed as a critical fungicide globally. The results demonstrate a significant association between Rad6 and conidial properties, heat shock response, and UV-B tolerance. Concurrently, the mutant strain exhibited heightened sensitivity to oxidative stress, cell wall interfering agents, DNA damage stress, and prolonged heat shock. Furthermore, the absence of Rad6 significantly extended the median lethal time (LT₅₀) of Galleria mellonella infected by B. bassiana. This delay could be attributed to reduced Pr1 proteases and extracellular cuticle-degrading enzymes, diminished dimorphic transition rates, and dysregulated antioxidant enzymes. Additionally, the absence of Rad6 had a more pronounced effect on genetic information processing, metabolism, and cellular processes under normal conditions. However, its impact was limited to metabolism in oxidative stress. This study offers a comprehensive understanding of the pivotal roles of Rad6 in conidial and hyphal stress tolerance, environmental adaptation, and the pathogenesis of Beauveria bassiana.