State Key Laboratory of Development Biology of Freshwater Fish, Hunan Provincial Key Laboratory for Microbial Molecular Biology, College of Life Science, Hunan Normal University, Lushan Road 36, Changsha, 410081, China.
Microb Cell Fact. 2021 Jul 22;20(1):141. doi: 10.1186/s12934-021-01630-2.
Acetoin utilization protein (acuC) is a type I histone deacetylase which is highly conserved in bacteria. The acuC gene is related to the acetylation/deacetylation posttranslational modification (PTM) system in S. spinosa. Spinosyns, the secondary metabolites produced by Saccharopolyspora spinosa, are the active ingredients in a family of insect control agents. However, the specific functions and influences of acuC protein in S. spinosa are yet to be characterized.
The knockout strain and overexpression strain were constructed separately with the shuttle vector pOJ260. The production of spinosyns A and D from S. spinosa-acuC were 105.02 mg/L and 20.63 mg/L, which were 1.82-fold and 1.63-fold higher than those of the wild-type strain (57.76 mg/L and 12.64 mg/L), respectively. The production of spinosyns A and D from S. spinosa-ΔacuC were 32.78 mg/L and 10.89 mg/L, respectively. The qRT-PCR results of three selected genes (bldD, ssgA and whiA) confirmed that the overexpression of acuC affected the capacities of mycelial differentiation and sporulation. Comparative proteomics analysis was performed on these strains to investigate the underlying mechanism leading to the enhancement of spinosad yield.
This study first systematically analysed the effects of overexpression acuC on the growth of S. spinosa and the production of spinosad. The results identify the differentially expressed proteins and provide evidences to understand the acetylation metabolic mechanisms which can lead to the increase of secondary metabolites.
乙酰利用蛋白（acuC）是一种 I 型组蛋白去乙酰化酶，在细菌中高度保守。acuC 基因与棘孢小单孢菌中的乙酰化/去乙酰化翻译后修饰（PTM）系统有关。 多杀菌素是由棘孢小单孢菌产生的次级代谢产物，是一类杀虫剂的有效成分。然而，acuC 蛋白在棘孢小单孢菌中的具体功能和影响尚未得到表征。
分别使用穿梭载体 pOJ260 构建了敲除菌株和过表达菌株。与野生型菌株（57.76mg/L 和 12.64mg/L）相比，棘孢小单孢菌 acuC 的 spinosyns A 和 D 的产量分别为 105.02mg/L 和 20.63mg/L，提高了 1.82 倍和 1.63 倍。棘孢小单孢菌-ΔacuC 的 spinosyns A 和 D 的产量分别为 32.78mg/L 和 10.89mg/L。三个选定基因（bldD、ssgA 和 whiA）的 qRT-PCR 结果证实 acuC 的过表达影响了菌丝分化和孢子形成的能力。对这些菌株进行了比较蛋白质组学分析，以研究导致多杀菌素产量提高的潜在机制。
本研究首次系统分析了过表达 acuC 对棘孢小单孢菌生长和多杀菌素生产的影响。结果鉴定了差异表达蛋白，并为理解导致次生代谢物增加的乙酰化代谢机制提供了证据。
