Discovery of a Novel Macrocyclic ATP Citrate Lyase Inhibitor.

ATP citrate lyase (ACLY) is an important metabolic enzyme involved in the synthesis of fatty acid and cholesterol. The inhibition of ACLY is considered as a promising therapeutic strategy for various metabolic diseases and numerous malignancies. In this study, a novel macrocyclic compound has been identified as a potent ACLY inhibitor with the "ring closing" strategy for conformational restriction based on -.

Diversity synthesis of indole derivatives catalyst control cyclization reaction of 2-indolylmethanols and azonaphthalene.

A series of indole-fused scaffolds and derivatives was synthesized the cyclization reaction of 2-indolylmethanols with azonaphthalene. These reactions were realized under mild reaction conditions through catalyst control, providing structurally diverse indole derivatives with moderate to excellent yields. This protocol also shows good substrate adaptability, especially in six-membered ring products.

Deciphering the Pharmacological Mechanisms of Taohe-Chengqi Decoction Extract Against Renal Fibrosis Through Integrating Network Pharmacology and Experimental Validation and .

Taohe-Chengqi decoction (THCQ), a classical traditional Chinese medicinal (TCM) formula, has been extensively used for treating chronic kidney disease (CKD). However, the biological activity and mechanisms of action of its constituents against renal fibrosis have not yet been investigated thoroughly. This study was aimed at devising an integrated strategy for investigating the bioactivity constituents and possible pharmacological mechanisms of the n-butanol extract of THCQ (NE-THCQ) against renal fibrosis.

Opposite effects of Drosophila C3PO on gene silencing mediated by esi-2.1 and miRNA-bantam.

Translin/TRAX complex, also named as C3PO, is evolutionarily conserved and participates in diverse cellular processes in different organisms from yeast to human. C3PO plays a critical role in the activation of RNA-induced silencing complexes by promoting the unwinding and degradation of passenger strand of exogenous siRNAs (exo-siRNAs) in Drosophila and human. Moreover, human C3PO (hC3PO) has been found to broadly repress miRNAs by degrading miRNA precursors.

Human Virus-Derived Small RNAs Can Confer Antiviral Immunity in Mammals.

RNA interference (RNAi) functions as a potent antiviral immunity in plants and invertebrates; however, whether RNAi plays antiviral roles in mammals remains unclear. Here, using human enterovirus 71 (HEV71) as a model, we showed HEV71 3A protein as an authentic viral suppressor of RNAi during viral infection. When the 3A-mediated RNAi suppression was impaired, the mutant HEV71 readily triggered the production of abundant HEV71-derived small RNAs with canonical siRNA properties in cells and mice.

Drosophila Dicer-2 has an RNA interference-independent function that modulates Toll immune signaling.

Dicer-2 is the central player for small interfering RNA biogenesis in the Drosophila RNA interference (RNAi) pathway. Intriguingly, we found that Dicer-2 has an unconventional RNAi-independent function that positively modulates Toll immune signaling, which defends against Gram-positive bacteria, fungi, and some viruses, in both cells and adult flies. The loss of Dicer-2 expression makes fruit flies more susceptible to fungal infection.

Human Enterovirus Nonstructural Protein 2CATPase Functions as Both an RNA Helicase and ATP-Independent RNA Chaperone.

RNA helicases and chaperones are the two major classes of RNA remodeling proteins, which function to remodel RNA structures and/or RNA-protein interactions, and are required for all aspects of RNA metabolism. Although some virus-encoded RNA helicases/chaperones have been predicted or identified, their RNA remodeling activities in vitro and functions in the viral life cycle remain largely elusive. Enteroviruses are a large group of positive-stranded RNA viruses in the Picornaviridae family, which includes numerous important human pathogens.

The identification and characterization of nucleic acid chaperone activity of human enterovirus 71 nonstructural protein 3AB.

Human enterovirus 71 (EV71) belongs to the genus Enterovirus in the family Picornaviridae and has been recognized as one of the most important pathogens that cause emerging infectious disease. Despite of the importance of EV71, the nonstructural protein 3AB from this virus is little understood for its function during EV71 replication. Here we expressed EV71 3AB protein as recombinant protein in a eukaryotic expression system and uncovered that this protein possesses a nucleic acid helix-destabilizing and strand annealing acceleration activity in a dose-dependent manner, indicating that EV71 3AB is a nucleic acid chaperone protein.

The RNA binding of protein A from Wuhan nodavirus is mediated by mitochondrial membrane lipids.

RNA replication of positive-strand (+)RNA viruses requires the lipids present in intracellular membranes, the sites of which viral replicases associate with. However, the direct effects of membrane lipids on viral replicases are still poorly understood. Wuhan nodavirus (WhNV) protein A, which associates with mitochondrial membranes, is the sole replicase required for RNA replication.

The self-interaction of a nodavirus replicase is enhanced by mitochondrial membrane lipids.

RNA replication of positive-strand (+)RNA viruses requires the protein-protein interactions among viral replicases and the association of viral replicases with intracellular membranes. Protein A from Wuhan nodavirus (WhNV), which closely associate with mitochondrial membranes, is the sole replicase required for viral RNA replication. Here, we studied the direct effects of mitochondrial membrane lipids (MMLs) on WhNV protein A activity in vitro.

Flock house virus RNA polymerase initiates RNA synthesis de novo and possesses a terminal nucleotidyl transferase activity.

Flock House virus (FHV) is a positive-stranded RNA virus with a bipartite genome of RNAs, RNA1 and RNA2, and belongs to the family Nodaviridae. As the most extensively studied nodavirus, FHV has become a well-recognized model for studying various aspects of RNA virology, particularly viral RNA replication and antiviral innate immunity. FHV RNA1 encodes protein A, which is an RNA-dependent RNA polymerase (RdRP) and functions as the sole viral replicase protein responsible for RNA replication.

A cypovirus VP5 displays the RNA chaperone-like activity that destabilizes RNA helices and accelerates strand annealing.

For double-stranded RNA (dsRNA) viruses in the family Reoviridae, their inner capsids function as the machinery for viral RNA (vRNA) replication. Unlike other multishelled reoviruses, cypovirus has a single-layered capsid, thereby representing a simplified model for studying vRNA replication of reoviruses. VP5 is one of the three major cypovirus capsid proteins and functions as a clamp protein to stabilize cypovirus capsid.

Characterization of a nodavirus replicase revealed a de novo initiation mechanism of RNA synthesis and terminal nucleotidyltransferase activity.

Nodaviruses are a family of positive-stranded RNA viruses with a bipartite genome of RNAs. In nodaviruses, genomic RNA1 encodes protein A, which is recognized as an RNA-dependent RNA polymerase (RdRP) and functions as the sole viral replicase protein responsible for its RNA replication. Although nodaviral RNA replication has been studied in considerable detail, and nodaviruses are well recognized models for investigating viral RNA replication, the mechanism(s) governing the initiation of nodaviral RNA synthesis have not been determined.

Newly discovered insect RNA viruses in China.

Insects are a group of arthropods and the largest group of animals on Earth, with over one million species described to date. Like other life forms, insects suffer from viruses that cause disease and death. Viruses that are pathogenic to beneficial insects cause dramatic economic losses on agriculture.

Membrane association of Wuhan nodavirus protein A is required for its ability to accumulate genomic RNA1 template.

One common feature of positive-strand RNA viruses is the association of viral RNA and viral RNA replicase proteins with specific intracellular membranes to form RNA replication complexes. Wuhan nodavirus (WhNV) encodes protein A, which is the sole viral RNA replicase. Here, we showed that WhNV protein A closely associates with mitochondrial outer membranes and colocalizes with viral RNA replication sites.

The nonstructural protein 2C of a Picorna-like virus displays nucleic acid helix destabilizing activity that can be functionally separated from its ATPase activity.

Picorna-like viruses in the Picornavirales order are a large group of positive-strand RNA viruses that include numerous important pathogens for plants, insects, and humans. In these viruses, nonstructural protein 2C is one of the most conserved proteins and contains ATPase activity and putative RNA helicase activity. Here we expressed 2C protein of Ectropis obliqua picorna-like virus (EoV; genus Iflavirus, family Iflaviridae, order Picornavirales) in a eukaryotic expression system and determined that EoV 2C displays ATP-independent nucleic acid helix destabilizing and strand annealing acceleration activity in a concentration-dependent manner, indicating that this picornaviral 2C is more like an RNA chaperone than like the previously predicted RNA helicase.

Periplaneta fuliginosa densovirus nonstructural protein NS1 contains an endonuclease activity that is regulated by its phosphorylation.

Periplaneta fuliginosa densovirus (PfDNV) is a single-stranded DNA virus, belonging to Densovirinae subfamily, Parvoviridae family. Parvovirus nonstructural protein 1 (NS1) contains various activities required for parvoviral DNA replication, like endonuclease, helicase and ATPase, which are regulated by serine/threonine phosphorylation. However, for PfDNV, NS1 endonuclease activity has not been determined.

Identification and characterization of RNA duplex unwinding and ATPase activities of an alphatetravirus superfamily 1 helicase.

Dendrolimus punctatus tetravirus (DpTV) belongs to the genus omegatetravirus of the Alphatetraviridae family. Sequence analysis predicts that DpTV replicase contains a putative helicase domain (Hel). However, the helicase activity in alphatetraviruses has never been formally determined.

Identification and characterization of Iflavirus 3C-like protease processing activities.

Viral replication and capsid assembly in the viruses in the order Picornavirales requires polyprotein proteolytic processing by 3C or 3C-like (3CL) proteases. We identified and characterized the 3CL protease of Ectropis obliqua virus (EoV) of the newly established family Iflaviridae (order Picornavirales). The bacterially expressed EoV 3CL protease domain autocatalytically released itself from larger precursors by proteolytic cleavage, and cleavage sites were determined via N-terminal sequencing of the cleavage products.

Targeting of dicer-2 and RNA by a viral RNA silencing suppressor in Drosophila cells.

RNA interference (RNAi) is a eukaryotic gene-silencing mechanism that functions in antiviral immunity in diverse organisms. To combat RNAi-mediated immunity, viruses encode viral suppressors of RNA silencing (VSRs) that target RNA and protein components in the RNAi machinery. Although the endonuclease Dicer plays key roles in RNAi immunity, little is known about how VSRs target Dicer.

RNA binding by a novel helical fold of b2 protein from wuhan nodavirus mediates the suppression of RNA interference and promotes b2 dimerization.

Wuhan nodavirus (WhNV) is a newly identified member of the Nodaviridae family with a bipartite genome of positive-sense RNAs. A nonstructural protein encoded by subgenomic RNA3 of nodaviruses, B2, serves as a potent RNA silencing suppressor (RSS) by sequestering RNA duplexes. We have previously demonstrated that WhNV B2 blocks RNA silencing in cultured Drosophila cells.

Internal initiation is responsible for synthesis of Wuhan nodavirus subgenomic RNA.

Nodaviruses are small nonenveloped spherical viruses with a bipartite genome of RNAs. In nodaviruses, subgenomic RNA3 (sgRNA3) plays a critical role in viral replication and survival, as it coordinates the replication of two viral genomic RNAs (RNA1 and RNA2) and encodes protein B2, which is a potent RNA-silencing inhibitor. Despite its importance, the molecular mechanism of nodaviral sgRNA3 synthesis is still poorly understood.

Characterization of Wuhan Nodavirus subgenomic RNA3 and the RNAi inhibition property of its encoded protein B2.

Wuhan Nodavirus (WhNV) is the first reported nodavirus isolated from insect in China. The viral genome consists of two positive-strand RNA, RNA1 and RNA2. RNA1 is 3149 nucleotides in length, and contains three putative Open Reading Frames (ORFs) which encode proteins A, B1 and B2, respectively.

Expression and characterization of RNA-dependent RNA polymerase of Ectropis obliqua virus.

Replication of positive-strand RNA virus is mediated by a virus- encoded RNA-dependent RNA polymerase (RdRp). To study the replication of Ectropis obliqua virus (EoV), a newly identified insect virus belonging to the family Iflaviradae, we expressed the RNA polymerase domain in Escherichia coli and purified it on a Ni-chelating HisTrap affinity column. It is demonstrated that EoV RdRp initiated RNA synthesis in a primerand poly (A)-dependent manner in vitro.