Structural basis of exoribonuclease-mediated mRNA transcription termination.

Efficient termination is required for robust gene transcription. Eukaryotic organisms use a conserved exoribonuclease-mediated mechanism to terminate the mRNA transcription by RNA polymerase II (Pol II). Here we report two cryogenic electron microscopy structures of Saccharomyces cerevisiae Pol II pre-termination transcription complexes bound to the 5'-to-3' exoribonuclease Rat1 and its partner Rai1.

Cryo-EM structures of the plant plastid-encoded RNA polymerase.

Chloroplasts are green plastids in the cytoplasm of eukaryotic algae and plants responsible for photosynthesis. The plastid-encoded RNA polymerase (PEP) plays an essential role during chloroplast biogenesis from proplastids and functions as the predominant RNA polymerase in mature chloroplasts. The PEP-centered transcription apparatus comprises a bacterial-origin PEP core and more than a dozen eukaryotic-origin PEP-associated proteins (PAPs) encoded in the nucleus.

A cryo-EM structure of KTF1-bound polymerase V transcription elongation complex.

De novo DNA methylation in plants relies on transcription of RNA polymerase V (Pol V) along with KTF1, which produce long non-coding RNAs for recruitment and assembly of the DNA methylation machinery. Here, we report a cryo-EM structure of the Pol V transcription elongation complex bound to KTF1. The structure reveals the conformation of the structural motifs in the active site of Pol V that accounts for its inferior RNA-extension ability.

Pol IV and RDR2: A two-RNA-polymerase machine that produces double-stranded RNA.

DNA methylation affects gene expression and maintains genome integrity. The DNA-dependent RNA polymerase IV (Pol IV), together with the RNA-dependent RNA polymerase RDR2, produces double-stranded small interfering RNA precursors essential for establishing and maintaining DNA methylation in plants. We determined the cryo–electron microscopy structures of the Pol IV–RDR2 holoenzyme and the backtracked transcription elongation complex.

[Acupoint catgut embedding improves dysmenorrhea by suppressing activation of NLRP3 inflammasomes in uterine tissues in primary dysmenorrhea rats].

Objective: To observe the effect of acupoint catgut embedding on the expression of nucleotide-binding oligomerization domain (NOD)-like receptor protein 3 (NLRP3) inflammasome, interleukin (IL)-1β and IL-18 in the uterine tissue of primary dysmenorrhea (PD) rats, so as to explore its underlying mechanisms in improving PD.

Methods: Forty female SD rats were randomly divided into control, model, acupoint catgut embedding and medication groups (＝10 in each group). The PD model was established by subcutaneous injection of Estradiol Benzoate (0.

[Effects of exogenous ABA on translocation of photosynthate to fruit of Fuji apple during late stage of fruit rapid-swelling.].

To clarify the effects and underlying mechanism of ABA on sugar accumulation in apple fruits, C trace technique was used to examined the effects of different ABA levels (0, 50, 100 and 150 mg·L) and fluoridone (ABA biosynthesis inhibitor) on translocation of photosynthate to fruit during late stage of fruit rapid-swelling in five-year-old 'Yanfu3'/M26/Malus hupehensis Rehd. The results showed that the activities of related enzyme in sugar metabolism, the relative expression of sucrose transporter gene MdSUT1, MdSUT2.2 and sorbitol transporter gene MdSOT3 tended to increase first and then decrease with increasing ABA concentration, with a peak in 100 mg·LABA treatment.

[Effects of split combined application of organic-inorganic fertilizers on plant growth, N absorption, utilization and loss of Gala apple tree].

Fifteen-year-old 'Gala'/M. hupehensis Rehd. trees and N trace technique were used to explore the effects of split combined application of organic-inorganic fertilizers on plant growth, N absorption, utilization and loss.

Pathological Changes in APP/PS-1 Transgenic Mouse Models of Alzheimer's Disease Treated with Ganoderma Lucidum Preparation.

Objective To explore the efficacy of ganoderma lucidum preparation(Ling Zhi) in treating APP/PS-1 transgenic mouse models of Alzheimer's disease(AD).Methods APP/PS-1 transgenic mice of 4 months were randomly divided into model group,ganoderma lucidum treatment groups,including high [2250 mg/(kg·d)] and middle [750 mg/(kg·d)] dose groups,i.e.

Effectiveness of Ganoderma lucidum preparation in treating simian acquired immune deficiency syndrome.

Objective: To explore the effectiveness of the traditional Chinese herbal medicine Lingzhi (Ganoderma lucidum) preparation in treating simian acquired immune deficiency syndrome (SAIDS).

Methods: Five female adult Chinese rhesus monkeys were inoculated rectally with SIVmac239, and were all diagnosed as SAIDS by laboratory and clinical examinations 17 months later. Of these 5 monkeys, 3 (#393, #374, and #381; treatment group) were orally administered with Ganoderma lucidum (2 spores powder capsules plus 2 spores oil capsules on a daily basis), and the remaining other two monkeys (#348 and #361) served as control and did not receive treatment.

Beneficial effect of HHI-I on cerebral microcirculation, blood-brain barrier in rats and anti-hypoxic activity in mice.

Objective: To investigate the effect of HHI-I (I) on the cerebral microcirculation, the blood-brain barrier permeability in rats and anti-hypoxic activity in mice.

Methods: (1) The blood microcirculation of the brain in rats was investigated by laser Doppler flowmetry with the probes laid on the cerebral pia mater or inserted into the brain parenchyma. (2) The protective action of HHI-I against the brain microcirculation disturbance induced by intravenous injection of high-molecular dextran (10%, 9 mL/kg) was observed.

[Comparison of intravenous and intrarectal SIVmac239 infections in rhesus monkeys of Chinese origin].

Objective: To investigate the biological and clinical features of Chinese rhesus monkeys after intravenous (IV) and intrarectal (IR) challenge with SIVmac239 in rhesus monkeys of Chinese origin, and compare the differences between the routes of infection.

Methods: Rhesus monkeys of Chinese origin were inoculated with SIVmac239 either by IV (n = 19) or IR (n = 6) routes. Simian immunodeficiency virus (SIV)-specific antibody titer, CD4 + T cell counting, plasma SIV load, lymph node pathology, and clinical manifestations were compared between these two groups 232 or 168 days after challenging.

[Autoantibodies and autoimmunity in simian immunodeficiency virus-infected monkeys].

Objective: To study the relationship between simian acquired immunodeficiency syndromn (SAIDS) and autoimmunity in simian immunodeficiency virus (SIV)-infected monkeys.

Methods: Indirect immunofluorescence assays were performed to detect plasma or serum autoantibodies in SIV-infected monkeys. The heart, liver, spleen, lung, kidney, and lymph node of BALB/c mice, a strain of endothelial cell ECV304, and granulocytes were used as target antigens.

Protective effect of YHI and HHI-I against experimental acute pancreatitis in rabbits.

AIM:To observe the protective effect of combined i.v. administraction of Yuanhu injection (YHI) and Huoxuehuayu injection-I (HHI-I) against acute pancreatitis (AP) in rabbits.