scholarly journals Ginsenoside Compound K Assisted G-Quadruplex Folding and Regulated G-Quadruplex-Containing Transcription

Molecules ◽  
2021 ◽  
Vol 26 (23) ◽  
pp. 7339
Author(s):  
Yan Zhang ◽  
Zhidong Qiu ◽  
Ming Zhu ◽  
Ye Teng

Ginsenoside compound K (CK) is one of the major metabolites of the bioactive ingredients in Panax ginseng, which presents excellent bioactivity and regulates the expression of important proteins. In this work, the effects of CK on G-quadruplexes (G4s) were quantitatively analyzed in the presence and absence of their complementary sequences. CK was demonstrated to facilitate the formation of G4s, and increase the quantity of G4s in the competition with duplex. Thermodynamic experiments suggested that the electrostatic interactions were important for G4 stabilization by CK. CK was further found to regulate the transcription of G4-containing templates, reduce full-length transcripts, and decrease the transcription efficiency. Our results provide new evidence for the pharmacological study of ginsenosides at the gene level.

2014 ◽  
Vol 9 (1) ◽  
pp. 11 ◽  
Author(s):  
Carmen Ka-Man Law ◽  
Hoi-Hin Kwok ◽  
Po-Ying Poon ◽  
Chi-Chiu Lau ◽  
Zhi-Hong Jiang ◽  
...  

Cell Research ◽  
2014 ◽  
Vol 24 (6) ◽  
pp. 770-773 ◽  
Author(s):  
Xing Yan ◽  
Yun Fan ◽  
Wei Wei ◽  
Pingping Wang ◽  
Qunfang Liu ◽  
...  

2019 ◽  
Vol 46 (5) ◽  
pp. 5323-5332 ◽  
Author(s):  
Xijun Chen ◽  
Hui Li ◽  
Qing Yang ◽  
Xingcheng Lan ◽  
Jifeng Wang ◽  
...  

2020 ◽  
Vol 11 ◽  
Author(s):  
Silin Zhang ◽  
Meilan Zhang ◽  
Jiaxin Chen ◽  
Jiaqi Zhao ◽  
Jielin Su ◽  
...  

This study aimed to demonstrate that ginsenoside compound K (20 (S)-ginsenoside CK; CK) downregulates Bcl-2-associated transcription factor 1 (Bclaf1), which inhibits the hypoxia-inducible factor-1α (HIF-1α)-mediated glycolysis pathway to inhibit the proliferation of liver cancer cells. Treatment of hepatoma cells (Bel-7404 and Huh7) under hypoxic conditions with different concentrations of CK showed that CK inhibited the proliferation of hepatoma cells in a time- and concentration-dependent manner; furthermore, the ability of the cells to form colonies was reduced, and cell growth was blocked in the G0/G1 phase. CK promoted the degradation of HIF-1α ubiquitination in liver cancer cells by regulating the expression of HIF-1α and related ubiquitination proteins; moreover, it reduced the activity of key enzymes involved in glycolysis, the pressure of cellular glycolysis, and the rate of real-time ATP production, thereby inhibiting the glycolysis pathway. It also decreased the expression of Bclaf1 in hypoxic liver cancer cells and thus reduced the ability of Bclaf1 to bind to HIF-1α. CK treatment of Bel-7404 and Huh7 cells with CRISPR/Cas9-engineered knock out of Bclaf1 gene under hypoxic conditions further suppressed the expression of HIF-1α, promoted HIF-1α ubiquitination, and inhibited the glycolysis pathway. In a rat model of primary liver cancer induced by diethylnitrosamine, positron emission tomography and computed tomography scans showed that after CK administration, tumor tissue volumes were reduced and glucose uptake capacity decreased. Increased Bclaf1 and HIF-1α expression promoted the ubiquitination of HIF-1α and inhibited the glycolysis pathway, thereby inhibiting the proliferation of liver cancer cells. In summary, this study confirmed by in vitro and in vivo experiments that in hypoxic liver cancer cells CK downregulates the expression of Bclaf1, inhibits the HIF-1α-mediated glycolysis pathway, and inhibits cell proliferation, suggesting that the CK-mediated effects on Bclaf1 may represent a novel therapeutic approach for the treatment of liver cancer patients.


2015 ◽  
Vol 112 (31) ◽  
pp. 9608-9613 ◽  
Author(s):  
Brahim Heddi ◽  
Vee Vee Cheong ◽  
Herry Martadinata ◽  
Anh Tuân Phan

Four-stranded nucleic acid structures called G-quadruplexes have been associated with important cellular processes, which should require G-quadruplex–protein interaction. However, the structural basis for specific G-quadruplex recognition by proteins has not been understood. The DEAH (Asp-Glu-Ala-His) box RNA helicase associated with AU-rich element (RHAU) (also named DHX36 or G4R1) specifically binds to and resolves parallel-stranded G-quadruplexes. Here we identified an 18-amino acid G-quadruplex-binding domain of RHAU and determined the structure of this peptide bound to a parallel DNA G-quadruplex. Our structure explains how RHAU specifically recognizes parallel G-quadruplexes. The peptide covers a terminal guanine base tetrad (G-tetrad), and clamps the G-quadruplex using three-anchor-point electrostatic interactions between three positively charged amino acids and negatively charged phosphate groups. This binding mode is strikingly similar to that of most ligands selected for specific G-quadruplex targeting. Binding to an exposed G-tetrad represents a simple and efficient way to specifically target G-quadruplex structures.


Sign in / Sign up

Export Citation Format

Share Document