Cloning and characterization of ribonuclease T2 gene (RNHe30) from the basidiomycete, Hericium erinaceum

Genome-wide identification and characterization of legume T2 Ribonuclease gene family and analysis of GmaRNS9, a soybean T2 Ribonuclease gene, function in nodulation

T2 ribonuclease family (RNaseT2) proteins are secretory and nonspecific endoribonucleases that have a large conserved biological role. Family members of RNaseT2 are found in every organism and carry out important biological functions. However, little is known about the functions of these proteins in legumes, including potential roles in symbiotic nodulation. This study aimed to characterize and perform bioinformatic analysis of RNaseT2 genes in four legume species that their genome was sequenced. In total, 60 RNaseT2 genes were identified and characterized. By analyzing their phylogeny, we divided these RNaseT2 into five clades. Expression analysis of RNaseT2 genes indicated that these genes are expressed in various tissues, and the most expression level was related to the pod, flower, and root. Moreover, GmaRNS9 expression analysis in soybean was consistent with in silico studies and demonstrated that this gene usually has high root tip expression. GmaRNS9 expression was reduced by Bradyrhizobium japonicum inoculation and nodule formation. Reduced expression of this gene was possibly controlled by the GmNARK gene either directly or pleiotropically through increased phosphorus requirements during increased nodulation. However, the nutrient stress (phosphate and nitrate starvation) led to an increase in the expression level of GmRNS9. In silico and quantitative gene expression analyses showed that RNaseT2 genes could play important roles in the growth and development of legumes as well as nodulation.

Erinacerins, Novel Glioma Inhibitors from Hericium erinaceus, Induce Apoptosis of U87 Cells through Bax/Capase-2 Pathway

BACKGROUND

Glioma is the most common tumor of the central nervous system. Hericium erinaceus, which has been reported to have a variety of pharmacological activities, is a widely used Traditional Chinese Medicine (TCM), and also a kind of delicious food accepted by the public.

METHODS AND RESULTS

In this study, two new natural products, compounds 1 and 2, were isolated and identified from Hericium erinaceus. They were named erinacerin O and erinacerin P, respectively, after the structural identification, and their effects on human glioma cell line U87 were evaluated. Erinacerin P (2) exhibited obvious cytotoxicity on human glioma cell line U87. The IC50 value of 2 was 19.32μg/mL. The results showed that the apoptosis of U87 cells treated with 2 increased and the morphology of U87 cells altered significantly. Flow cytometry experiment showed that 2 could significantly increase the apoptosis rate of U87 cells and reduce DNA replication. Western blot results suggested the Bax/capase-3 pathway was involved in the U87 cell apoptosis induced by 2.

CONCLUSION

Erinacerin O and Erinacerin P are novel compounds obtained from Hericium erinaceus and Erinacerin P could be a potential novel glioma inhibitor.

Stable and transient transformation, and a promoter assay in the selective lignin-degrading fungus, Ceriporiopsis subvermispora

A genetic transformation system was developed for the selective white rot basidiomycete Ceriporiopsis subvermispora using a modified protocol with polyethylene glycol and CaCl₂ treatment of the protoplasts and plasmids harboring recombinant hygromycin phosphotransferase (hph) driven by a homologous promoter. During repeated transfer on fresh potato dextrose agar plates containing 100 µg/ml hygromycin B, most transformants lost drug resistance, while the remaining isolates showed stable resistance over five transfers. No drug-resistant colonies appeared in control experiments without DNA or using a promoter-less derivative of the plasmid, indicating that a transient expression of the recombinant hph was driven by the promoter sequence in these unstable drug-resistant transformants. Southern blot analysis of the stable transformants revealed random integration of the plasmid DNA fragment in the chromosome at different copy numbers. This transformation system yielding mostly transient transformants was successfully used for promoter assay experiments, and only a 141-bp fragment was found to be essential for the basic promoter function of glyceraldehyde dehydrogenase gene (gpd) in this fungus. Subsequent mutational analyses suggested that a TATAA sequence is important for the basic promoter function of gpd gene. The promoter assay system will enable the functional analysis of gene expression control sequences quickly and easily, mostly in the absence of undesirable effects from differences in copy number and chromosomal position of an integrated reporter gene among stable transformants.

Structure elucidation of a bioactive polysaccharide from fruiting bodies of Hericium erinaceus in different maturation stages

HPB-3, a heteropolysaccharide, with a mean molecular weight of 1.5×10(4)Da, was obtained from the maturating-stage IV, V and VI fruiting body of Hericium erinaceus, exhibited higher macrophages stimulation activities, was able to upregulate the functional events mediated by activated macrophages, such as production of nitric oxide (NO). Monosaccharide composition analysis showed that HPB-3 comprised l-fucose, d-galactose and d-glucose in the ratio of 5.2:23.9:1. Its chemical structure was characterized by sugar and methylation analysis, along with (1)H and (13)C NMR spectroscopy, including (1)H-(1)H COSY, TOCSY, NOESY, HMQC and HMBC experiments. The results indicated that HPB-3 contained a-(1/6)-linked galactopyranosyl backbone, partially with a side chain composed of α-l-fucopyranose at the O-2 position. The predicted primary structure of the polysaccharide was established as below.