College of Food Science and Technology, Huazhong Agricultural University, Wuhan, China.
College of Science, Huazhong Agricultural University, Wuhan, China.
Appl Biochem Biotechnol. 2022 Dec;194(12):5702-5716. doi: 10.1007/s12010-022-04030-3. Epub 2022 Jul 8.
Monascus species are the producers of Monascus azaphilone pigments (MonAzPs) and lipid-lowering component Monacolin K, which have been widely used as food colorant and health products. In this study, silent information regulator 2 (Sir2) homolog (MrSir2) was characterized, and its impacts on the development and MonAzPs production of Monascus ruber were evaluated. Enzyme activity test in vitro showed that MrSir2 was an NAD-dependent histone deacetylase. Compared to WT, Δmrsir2 strain accumulated more acetylated lysine residues of histone H3 subunit during its vegetative growth phase, and it exhibited accelerated mycelial aging, more spores, increased resistance to oxidative stress, and more MonAzPs production. RNA-Seq-based transcriptome analysis revealed that MrSir2 mainly regulated the gene expression in macromolecular metabolism such as carbohydrates, proteins, and nucleotides, as well as genes encoding cell wall synthesis and cell membrane component, indicating that MrSir2 probably facilitates the metabolic transition from the primary growth phase to the mycelial aging. Taken together, MrSir2 mainly targets H3 subunit at the vegetative growth phase and affects the development of M. ruber and MonAzPs production.
红曲霉属的 Monascus 种是 Monascus azaphilone 色素（MonAzPs）和降脂成分 Monacolin K 的生产者，这些成分已被广泛用作食品着色剂和保健品。在本研究中，对沉默信息调节因子 2（Sir2）同源物（MrSir2）进行了表征，并评估了其对红曲霉生长发育和 MonAzPs 生产的影响。体外酶活性测试表明，MrSir2 是一种 NAD 依赖性组蛋白去乙酰化酶。与 WT 相比，Δmrsir2 菌株在其营养生长阶段积累了更多组蛋白 H3 亚基的乙酰化赖氨酸残基，表现出菌丝老化加速、孢子增多、氧化应激抗性增强和 MonAzPs 产量增加。基于 RNA-Seq 的转录组分析表明，MrSir2 主要调控碳水化合物、蛋白质和核苷酸等大分子代谢以及细胞壁合成和细胞膜成分编码基因的表达，表明 MrSir2 可能有助于从初级生长阶段向菌丝老化的代谢转变。综上所述，MrSir2 主要在营养生长阶段针对 H3 亚基，并影响红曲霉的发育和 MonAzPs 的生产。
