Title:Expression Analysis of Lanosterol Synthase Gene in Dynamic Accumulation of Triterpenoids in Sanghuangporus baumii
Volume: 29
Issue: 1
Author(s): Xu Tong Wang, Ting Ting Sun, Jian Sun, Shixin Wang and Li Zou*
Affiliation:
- College of Forestry, Northeast Forestry University, Harbin 150040, China
Keywords:
Lanosterol synthase, Sanghuangporus baumii, triterpenoids, dynamic accumulation, promoter, protein expression.
Abstract: Background: Sanghuangporus baumii is a traditional Chinese medicine with anti- cancer,
anti-tumor, and anti-inflammatory effects. Triterpenoids are one of the main medicinal ingredients
found in S. baumii. However, the dynamic changes of triterpenoids content and its molecular
regulation mechanism are still unclear.
Objective: Some studies have shown that Lanosterol synthase ( LS) is a key enzyme involved in the
mevalonate pathway (MVA pathway) to produce lanosterol, which is a precursor for synthesizing
S. baumii triterpenoids. Therefore, the study of LS gene and expression characteristics can provide
clues for the further study of triterpenoids synthesis.
Methods: The PCR, RACE PCR, RT-PCR, homologous recombination and prokaryotic expression
technology were used to research the gene characteristic and dynamic changes of LS transcription
level.
Results: The S. baumii LS sequence included a 5’-untranslated region (129 bp), a 3’-untranslated region
(87 bp), and an open reading frame (2,229 bp) encoding 734 amino acids. The S. baumii LS
protein was expressed in E. coli BL21 (DE3). The transcription start site of the S. baumii LS promoter
sequence ranged from 1 740 bp to 1790 bp. The LS promoter contained 12 CAAT-boxes, 5
ABREs, 6 G-Boxes, 6 CGTCA-motifs, and so on. The LS transcription levels were the highest on
day 11 in mycelia (1.6-fold), and the triterpenoids content also gradually increased. The transcription
levels began to decrease on day 13, but the triterpenoids content still increased.
Conclusion: The S. baumii LS was cloned and characterized to help to understand the mechanism
of triterpenoids synthesis. In addition, we studied the relationship between LS transcription level
and triterpenoid dynamic accumulation, and we found that they had a certain correlation.