Putative methyltranferase LaeA and LaeA-like proteins, which are conserved in many filamentous fungi, regulate the sporogenesis and biosynthesis of secondary metabolites. In this study, we reported the biological function of a LaeA-like methyltransferase, Penicillium oxalicum Mtr23B, which contains a methyltransf_23 domain and an S-adenosylmethionine binding domain, in controlling spore pigment formation and in the expression of secondary metabolic gene cluster and glycoside hydrolase genes. Additionally, we compared Mtr23B and LaeA, and determined their similarities and differences in terms of their roles in regulating the above biological processes. mtr23B had the highest transcriptional level among the 12 members of the methyltransf_23 family in P. oxalicum. The colony color of Δmtr23B (deletion of mtr23B) was lighter than that of ΔlaeA, although Δmtr23B produced ∼19.2-fold more conidia than ΔlaeA. The transcriptional levels of abrA, abrB/yA, albA/wA, arpA, arpB, and aygA, which are involved in the dihydroxynaphtalene–melanin pathway, decreased in Δmtr23B. However, Mtr23B had a little effect on brush-like structures and conidium formation, and had a different function from LaeA. Mtr23B extensively regulated glycoside hydrolase gene expression. The absence of Mtr23B remarkably repressed prominent cellulase- and amylase-encoding genes in the whole culture period, while the effect of LaeA mainly occurred in the later phases of prolonged batch cultures. Similar to LaeA, Mtr23B was involved in the expression of 10 physically linked regions containing secondary metabolic gene clusters; the highest regulatory activities of Mtr23B and LaeA were observed in BrlA-dependent cascades. Although LaeA interacted with VeA, Mtr23B did not interact with VeA directly. We assumed that Mtr23B regulates cellulase and amylase gene transcription by interacting with the CCAAT-binding transcription factor HAP5 and chromatin remodeling complex.

假定的甲基转移酶 LaeA 和 LaeA 样蛋白在许多丝状真菌中是保守的，可调节次生代谢物的孢子发生和生物合成。在这项研究中，我们报告了 LaeA 样甲基转移酶草酸青霉 Mtr23B的生物学功能，该酶包含一个甲基转移域和一个 S-腺苷甲硫氨酸结合域，在控制孢子色素形成和次级代谢基因簇和糖苷水解酶的表达方面的生物学功能基因。此外，我们比较了 Mtr23B 和 LaeA，并确定了它们在调节上述生物过程中的作用方面的异同。mtr23B在P中的methyltransf_23 家族的12 个成员中具有最高的转录水平。草酸。Δ的菌落颜色mtr23B（缺失的mtr23B）比Δ的打火机LAEA，虽然Δ mtr23B产生~19.2倍Δ更分生孢子LAEA。参与二羟基萘-黑色素通路的abrA、abrB / yA、albA / wA、arpA、arpB和aygA的转录水平在 Δ mtr23B 中降低. 然而，Mtr23B 对刷状结构和分生孢子形成的影响很小，并且具有与 LaeA 不同的功能。Mtr23B 广泛调节糖苷水解酶基因表达。在整个培养期间，Mtr23B 的缺失显着抑制了突出的纤维素酶和淀粉酶编码基因，而 LaeA 的作用主要发生在长时间分批培养的后期。与 LaeA 类似，Mtr23B 参与了 10 个包含次级代谢基因簇的物理连接区域的表达；在 BrlA 依赖性级联反应中观察到 Mtr23B 和 LaeA 的最高调节活性。尽管 LaeA 与 VeA 相互作用，但 Mtr23B 不直接与 VeA 相互作用。