• Journal of Life Science
• /
• v.32 no.6
• /
• pp.463-467
• /
• 2022

As a result of applying the COG (Cluster of Orthologous Groups of Protein) algorithm to 1,309 species to confirm the conserved genes of prokaryotes, ribosomal protein S11 (COG0100) was identified. The numbers of conservative genes were 2, 5, 5, and 6 in 1,308, 1,307, 1,306, and 1,305 species, respectively. Twenty-nine genes were conserved in over 1,302 species, and they encoded 23 ribosomal proteins, 3 tRNA synthetases, 2 translation factors, and 1 RNA polymerase subunit. Most of them were related to protein production, suggesting the importance of protein expression in prokaryotes. The highest conservative COG was COG0048 (ribosomal protein S12) among the 29 COGs. The 29 conserved genes usually have one protein for each prokaryote. COG0090 (ribosomal protein L2) had not only the lowest conservation value but also the largest standard deviation of phylogenetic distance value. As COG0090 is not only a member of the ribosome, but also a regulator of replication and transcription, it could be inferred that prokaryotes have large variations in COG0090 to survive in various environments. This study could provide data necessary for basic science, tumor control, and development of antibacterial agents.

• Journal of Microbiology and Biotechnology
• /
• v.21 no.4
• /
• pp.387-390
• /
• 2011

Nude mice (BALB/c) were grafted with human 293 cells and PERV (porcine endogenous retrovirus)-IRES-EGFP (a packageable retroviral vector plasmid containing an internal ribosome entry site-enhanced green fluorescent protein)-producing pig PK15 cells in order to determine whether the pig cells could transmit PERV-IRES-EGFP to mice and human 293 cells in vivo. None of the transplanted human 293 cell lines were infected by PERV, but PCR analysis identified PERV-B provirus integration into both the heart and salivary gland of the inoculated nude mice. Our data indicate that hearts and salivary glands can be used to identify PERV-B receptors.

• Journal of Microbiology and Biotechnology
• /
• v.30 no.1
• /
• pp.38-43
• /
• 2020

Hand, foot, and mouth disease (HFMD) is caused by enterovirus 71 (EV71) in infants and children under six years of age. HFMD is characterized by fever, mouth ulcers, and vesicular rashes on the palms and feet. EV71 also causes severe neurological manifestations, such as brainstem encephalitis and aseptic meningitis. Recently, frequent outbreaks of EV71 have occurred in the Asia-Pacific region, but currently, no effective antiviral drugs have been developed to treat the disease. In this study, we investigated the antiviral effect of salvianolic acid B (SalB) on EV71. SalB is a major component of the Salvia miltiorrhiza root and has been shown to be an effective treatment for subarachnoid hemorrhages and myocardial infarctions. HeLa cells were cultured in 12-well plates and treated with SalB (100 or 10 ㎍/ml) and 10⁶ PFU/ml of EV71. SalB treatment (100 ㎍/ml) significantly decreased the cleavage of the eukaryotic eIF4G1 protein and reduced the expression of the EV71 capsid protein VP1. In addition, SalB treatment showed a dramatic decrease in viral infection, measured by immunofluorescence staining. The Akt signaling pathway, a key component of cell survival and proliferation, was significantly increased in EV71-infected HeLa cells treated with 100 ㎍/ml SalB. RT-PCR results showed that the mRNA for anti-apoptotic protein Bcl-2 and the cell cycle regulator Cyclin-D1 were significantly increased by SalB treatment. These results indicate that SalB activates Akt/PKB signaling and inhibits apoptosis in infected HeLa cells. Taken together, these results suggest that SalB could be used to develop a new therapeutic drug for EV71-induced HFMD.

• Molecules and Cells
• /
• v.45 no.12
• /
• pp.911-922
• /
• 2022

A structural protein of SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2), nucleocapsid (N) protein is phosphorylated by glycogen synthase kinase (GSK)-3 on the serine/arginine (SR) rich motif located in disordered regions. Although phosphorylation by GSK-3β constitutes a critical event for viral replication, the molecular mechanism underlying N phosphorylation is not well understood. In this study, we found the putative alpha-helix L/FxxxL/AxxRL motif known as the GSK-3 interacting domain (GID), found in many endogenous GSK-3β binding proteins, such as Axins, FRATs, WWOX, and GSKIP. Indeed, N interacts with GSK-3β similarly to Axin, and Leu to Glu substitution of the GID abolished the interaction, with loss of N phosphorylation. The N phosphorylation is also required for its structural loading in a virus-like particle (VLP). Compared to other coronaviruses, N of Sarbecovirus lineage including bat RaTG13 harbors a CDK1-primed phosphorylation site and Gly-rich linker for enhanced phosphorylation by GSK-3β. Furthermore, we found that the S202R mutant found in Delta and R203K/G204R mutant found in the Omicron variant allow increased abundance and hyper-phosphorylation of N. Our observations suggest that GID and mutations for increased phosphorylation in N may have contributed to the evolution of variants.

• Biomolecules & Therapeutics
• /
• v.26 no.6
• /
• pp.576-583
• /
• 2018

Human rhinoviruses (HRV) are one of the major causes of common cold in humans and are also associated with acute asthma and bronchial illness. Heat-shock protein 90 (Hsp90), a molecular chaperone, is an important host factor for the replication of single-strand RNA viruses. In the current study, we examined the effect of the Hsp90 inhibitor pochonin D, in vitro and in vivo, using a murine model of human rhinovirus type 1B (HRV1B) infection. Our data suggested that Hsp90 inhibition significantly reduced the inflammatory cytokine production and lung damage caused by HRV1B infection. The viral titer was significantly lowered in HRV1B-infected lungs and in Hela cells upon treatment with pochonin D. Infiltration of innate immune cells including granulocytes and monocytes was also reduced in the bronchoalveolar lavage (BAL) by pochonin D treatment after HRV1B infection. Histological analysis of the lung and respiratory tract showed that pochonin D protected the mice from HRV1B infection. Collectively, our results suggest that the Hsp90 inhibitor, pochonin D, could be an attractive antiviral therapeutic for treating HRV infection.

• Bulletin of the Korean Chemical Society
• /
• v.33 no.11
• /
• pp.3676-3680
• /
• 2012

An Epstein-Barr virus (EBV)-based plasmid contains the EBV nuclear antigen 1 (EBNA1) gene and EBV replication origin (oriP) sequence. Since EBNA1 (the only EBV-encoded protein) is combined with oriP, it is replicated simultaneously with chromosomal DNA in human, primate, and canine cells and is faithfully segregated at a stable copy number upon cell division. Consequently, it can be used to stably express gene inserts over a prolonged time in target cells. We have previously shown that the polyamidoamine (PAMAM) dendrimer can be surface-modified with L-arginine. Arginine is present at a high frequency in the transactivator of transcription (Tat) sequences of human immunodeficiency virus (HIV). It presents high membrane permeability and permits effective transfer of DNA inside the cells. In this study, we constructed two kinds of recombinant DNA by inserting the luciferase gene and enhanced green fluorescence protein (eGFP) gene as reporter genes into the pCEP4 plasmid vector. We measured dynamic light scattering (DLS) and zeta potential after preparing PAMAM-based cationic polymer/EBV-based plasmid complexes. We performed transfection of HEK 293 cell lines with the polyplexes, and monitored luciferase activity and green fluorescence protein (GFP) expression. Our results show that PAMAM-based cationic polymer/EBV plasmid complexes provide enhanced and sustained gene expression.

• Molecules and Cells
• /
• v.41 no.2
• /
• pp.127-133
• /
• 2018

Chromatin remodeling factors are involved in many cellular processes such as transcription, replication, and DNA damage response by regulating chromatin structure. As one of chromatin remodeling factors, remodeling and spacing factor 1 (RSF1) is recruited at double strand break (DSB) sites and regulates ataxia telangiectasia mutated (ATM) -dependent checkpoint pathway upon DNA damage for the efficient repair. RSF1 is overexpressed in a variety of cancers, but regulation of RSF1 levels remains largely unknown. Here, we showed that protein levels of RSF1 chromatin remodeler are temporally upregulated in response to different DNA damage agents without changing the RSF1 mRNA level. In the absence of SNF2h, a binding partner of RSF1, the RSF1 protein level was significantly diminished. Intriguingly, the level of RSF1-3SA mutant lacking ATM-mediated phosphorylation sites significantly increased, and upregulation of RSF1 levels under DNA damage was not observed in cells overexpressing ATM kinase. Furthermore, failure in the regulation of RSF1 level caused a significant reduction in DNA repair, whereas reconstitution of RSF1, but not of RSF1-3SA mutants, restored DSB repair. Our findings reveal that temporal regulation of RSF1 levels at its post-translational modification by SNF2h and ATM is essential for efficient DNA repair.

• Journal of Microbiology and Biotechnology
• /
• v.27 no.1
• /
• pp.189-196
• /
• 2017

Kaposi's sarcoma-associated herpesvirus (KSHV) is associated with formation of Kaposi's sarcoma, multicentric Castleman's disease, and primary effusion lymphoma. Replication and transcription activator (RTA) genes are expressed upon reactivation of KSHV, which displays a biphasic life cycle consisting of latent and lytic replication phases. RTA protein expression results in KSHV genome amplification and successive viral lytic gene expression. Transcriptional activity of viral lytic genes is regulated through epigenetic modifications. In Raji cells latently infected with Epstein-Barr virus, various modifications, such as acetylation and methylation, have been identified at specific lysine residues in histone H4 during viral reactivation, supporting the theory that expression of specific lytic genes is controlled by histone modification processes. Data obtained from chromatin immunoprecipitation and quantitative real-time PCR analyses revealed alterations in the H4K8ac and H4K20me3 levels at lytic gene promoters during reactivation. Our results indicate that H4K20me3 is associated with the maintenance of latency, while H4K8ac contributes to KSHV reactivation in infected TREx BCBL-1 RTA cells.

• Journal of Microbiology and Biotechnology
• /
• v.28 no.10
• /
• pp.1736-1748
• /
• 2018

Brucella abortus can survive and replicate within host macrophages, and great efforts have been made to demonstrate the genes involved in pathogenicity, such as internalization, in Brucella research. Here, intracellular responses were compared between THP-1 macrophage cells stimulated with B. abortus wild-type and four mutants (C1, C10, C27, and C32) using microarray to demonstrate the role of genes related to intracellular survival and replication. These mutants were generated by deleting genes encoding BAB_RS13225 (4-hydrobenzoate 3-monooxygenase, PHBH), BAB_RS00455 (heme exporter protein cytochrome C, CcmC), BAB_RS03675 (exopolyphosphatase, PPX), and BAB_RS13225 (peptidase M24). The results showed that mutants C1 and C10 induced significant suppression of survival levels and cytokine expression relative to wild-type in the THP-1 macrophage cells. These findings suggest that the BAB_RS13225 and BAB_RS00455 genes play important roles in survival within human macrophages. Conversely, mutants C27 and C32 induced significantly higher survival level than wild-type in the cells inhibiting cellular signal transduction. It is assumed that the BAB_RS03675 and BAB_RS13225 genes play a role in cellular resistance to B. abortus. Therefore, the disrupted genes are involved in B. abortus intracellular growth, and especially in its survival, and they could be effective targets for understanding the intracellular bacterium, B. abortus.

• Journal of the Korea Organic Resources Recycling Association
• /
• v.12 no.2
• /
• pp.61-71
• /
• 2004

These studies were conducted to investigate the effects of feeding dried leftover food (DLF) on growth, feed conversion and carcass characteristics of growing and finishing pigs. In experiment 1, seventy-five three-way cross-hybrids ($Yorkshire{\times}Landrace{\times}Duroc$) pigs weighing approximately 22 kg of body weight on average were assigned to five treatments in a completely randomized design. Each treatment had three replications with five pigs per replication. All pigs were fed experimental diets for 60 days. In experiment 2, seventy-five three-way cross-hybrids pigs weighing approximately 70 kg of body weight were fed experimental diets for 49 days. Each treatment had three replications with five pigs per replication. The treatments included 1) group offered control diet without DLF, 2) group offered diet containing DLF at 25%, 3) group offered diet containing DLF at 50%, 4) group offerred diet containing DLF at 25% with 10% higher protein level and 5) group offerred diet containing DLF at 50% and 20% higher protein level. Average daily gain of growing pigs was highest in control group among all the treatment groups except group offered diet containing DLF at 25% with no significant difference (P>0.05). Feed intake of DLF-offered groups were lower than that of control group while feed intake of groups fed diets containing DLF at 50% with 20% higher protein level was significantly higher (P<0.05) than that of control group. Feed conversion of growing pigs was not significantly different amont treatments although it seemed to be slightly improved in groups fed diets containing DLF at 25%. Average daily gain of finishing pigs fed diets containing DLF was significantly lower than that of control group. However there was no significant differences in average daily gain between groups fed diets containing DLF at 25% with 10% higher protein level and control group (P>0.05). Feed intakes were significantly decreased in DLF-fed groups compared to control group while there was no significant differences in feed intake between groups fed diets containing DLF with 10% and 20% higher protein levels and control group (P>0.05). Feed conversion was lowest in groups fed diets containing DLF at 25% with 10% higher protein level. However, there were no significant differences in feed conversion between groups fed diets containing DLF at 25% with 10% higher protein level and control group. Feed conversion of groups fed diets containing DLF at 50% was significantly higher than that of control group (P<0.05). Carcass weight was decreased with increasing levels of DLF in the diets. There were no significant differences in dressing percentage, backfat thickness and carcass grade among treatments. Feed cost per 1 kg body weight gain of finishing pigs was lowest in groups fed diets containing DLF at 25% with 10% higher protein level.