• Title/Summary/Keyword: protein-RNA interaction

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Pathway Analysis in HEK 293T Cells Overexpressing HIV-1 Tat and Nucleocapsid

  • Lee, Min-Joo;Park, Jong-Hoon
    • Journal of Microbiology and Biotechnology
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    • v.19 no.10
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    • pp.1103-1108
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    • 2009
  • The human immunodeficiency virus (HIV)-l protein Tat acts as a transcription transactivator that stimulates expression of the infected viral genome. It is released from infected cells and can similarly affect neighboring cells. The nucleocapsid is an important protein that has a related significant role in early mRNA expression, and which contributes to the rapid viral replication that occurs during HIV-1 infection. To investigate the interaction between the Tat and nucleocapsid proteins, we utilized cDNA micro arrays using pTat and flag NC cotransfection in HEK 293T cells and reverse transcription-polymerase chain reaction to validate the micro array data. Four upregulated genes and nine downregulated genes were selected as candidate genes. Gene ontology analysis was conducted to define the biological process of the input genes. A proteomic approach using PathwayStudio determined the relationship between Tat and nucleocapsid; two automatically built pathways represented the interactions between the upregulated and downregulated genes. The results indicate that the up- and downregulated genes regulate HIV-1 replication and proliferation, and viral entry.

Backbone assignment and structural analysis of anti-CRISPR AcrIF7 from Pseudomonas aeruginosa prophages

  • Kim, Iktae;Suh, Jeong-Yong
    • Journal of the Korean Magnetic Resonance Society
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    • v.25 no.3
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    • pp.39-44
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    • 2021
  • The CRISPR-Cas system provides adaptive immunity for bacteria and archaea against invading phages and foreign plasmids. In the Class 1 CRISPR-Cas system, multi-subunit Cas proteins assemble with crRNA to bind to DNA targets. To disarm the bacterial defense system, bacteriophages evolved anti-CRISPR (Acr) proteins that actively inhibit the host CRISPR-Cas function. Here we report the backbone resonance assignments of AcrIF7 protein that inhibits the type I-F CRISPR-Cas system of Pseudomonas aeruginosa using triple-resonance nuclear magnetic resonance spectroscopy. We employed various computational methods to predict the structure and binding interface of AcrIF7, and assessed the model with experimental data. AcrIF7 binds to Cas8f protein via flexible loop regions to inhibit target DNA binding, suggesting that conformational heterogeneity is important for the Cas-Acr interaction.

LINC01232 Promotes Gastric Cancer Proliferation through Interacting with EZH2 to Inhibit the Transcription of KLF2

  • Liu, Jing;Li, Zhen;Yu, Guohua;Wang, Ting;Qu, Guimei;Wang, Yunhui
    • Journal of Microbiology and Biotechnology
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    • v.31 no.10
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    • pp.1358-1365
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    • 2021
  • To clarify the role of long intergenic nonprotein-coding RNA 1232 (LINC01232) in the progression of gastric cancer and the potential mechanism, we analyzed the expression of LINC01232 in TCGA database using the GEPIA online tool, and the LINC01232 level in gastric cancer cell lines was detected by quantitative real time-polymerase chain reaction (qRT-PCR) as well. Cell proliferation assay, colony formation assay, transwell assay and tumor formation experiment in nude mice were conducted to observe the biological behavior changes of gastric cancer cells through the influence of LINC01232 knockdown. LncATLAS database and subcellular isolation assay were used for subcellular distribution of LINC01232 in gastric cancer cells. The interaction among LINC01232, zeste homolog 2 (EZH2) and kruppel-like factor 2 (KLF2) was clarified by RNA-protein interaction prediction (RPISeq), RNA immunoprecipitation (RIP), qRT-PCR and chromatin immunoprecipitation (ChIP) assay. Rescue experiments were further conducted to elucidate the biological function of LINC01232/KLF2 axis in the progression of gastric cancer. LINC01232 was upregulated in stomach adenocarcinoma (STAD) tissues and gastric cancer lines. LINC01232 knockdown inhibited the proliferative capacities of gastric cancer cells in vitro, and impaired in vivo tumorigenicity. LINC01232 was mainly distributed in the cell nucleus where it epigenetically repressed KLF2 expression via binding to the enhancer of EZH2, which was capable of binding to promoter regions of KLF2 to induce histone H3 lysine 27 trimethylation (H3K27me3). LINC01232 exerts oncogenic activities in gastric cancer via inhibition of KLF2, and therefore, the knockdown of KLF2 could reverse the regulatory effect of LINC01232 in the proliferative ability of gastric cancer cells.

Synergistic Effect of Interleukin-18 on the Expression of Lipopolysaccharide-Induced IP-10 (CXCL-10) mRNA in Mouse Peritoneal Macrophages

  • Kim, Hyo-Young;Kim, Jae-Ryong;Kim, Hee-Sun
    • Journal of Microbiology and Biotechnology
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    • v.16 no.10
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    • pp.1605-1612
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    • 2006
  • Interleukin (IL)-18, a member of the family of IL-l cytokine, is one of the principal inducers of $interferon-{\gamma}(IFN-{\gamma})$ in T lymphocytes and natural killer cells. The objective of the present study was to evaluate the effect of IL-18 on the expression of chemokine IP-10 (CXCL-10) mRNA in mouse peritoneal macrophages. IL-18 had very weak direct effect or synergistic effect with IL-12 on the expression of IP-10 mRNA in C57BL/6 mouse peritoneal macrophages. However, IL-18 pretreatment was found to playa cooperative role in the expression of lipopolysaccharide (LPS)-induced IP-10 mRNA. For the expression of LPS-induced IP-10 mRNA, the synergistic effect was detected after 16 h of IL-18 pretreatment prior to LPS stimulation. The expression level of CD14 in cells stimulated with LPS was not changed by IL-18 pretreatment, and the level of $IFN-{\gamma}$ production during IL-18 pretreatment plus LPS stimulation was barely discernible ($0.36{\pm}0.31pg/ml$). Namely, the synergistic effect of IL-18 pretreatment was not related to a change of LPS receptor, CD14 expression, and the production of $IFN-{\gamma}$ by the interaction between IL-18 and LPS. The synergistic effect of IL-18 pretreatment on the expression of LPS-induced IP-10 was related to not NF-kB but AP-1 activation, and associated with the extracellular signal-regulated kinase (ERK) pathway, one of the mitogen-activated protein kinase signaling pathways. These results provide useful information that may elucidate the mechanisms underlying the effect of IL-18 on the expression of IP-10 mRNA.

Over-Expression of Phospholipase D Isozymes Down-Regulates Protein Kinase CKII Activity via Proteasome-Dependent CKIIβ Degradation in NIH3T3 Cells

  • Yoon, Soo-Hyun;Min, Do Sik;Bae, Young-Seuk
    • Molecules and Cells
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    • v.27 no.3
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    • pp.299-305
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    • 2009
  • Over-expression of phospholipase D (PLD) 1 or PLD2 down-regulated CKII activity in NIH3T3 cells. The same results were found with catalytically inactive mutants of PLD isozymes, indicating that the catalytic activity of PLD is not required for PLD-mediated CKII inhibition. Consistent with this, 1-butanol did not alter CKII activity. The reduction in CKII activity in PLD-over-expressing NIH3T3 cells was due to reduced protein level, but not mRNA level, of the $CKII{\beta}$ subunit. This PLD-induced $CKII{\beta}$ degradation was mediated by ubiquitin-proteasome machinery, but MAP kinase and mTOR were not involved in $CKII{\beta}$ degradation. PLD isozymes interacted with the $CKII{\beta}$ subunit. Immunocytochemical staining revealed that PLD and $CKII{\beta}$ colocalize in the cytoplasm of NIH3T3 cells, especially in the perinuclear region. PLD binding to $CKII{\beta}$ inhibited $CKII{\beta}$ autophosphorylation, which is known to be important for $CKII{\beta}$ stability. In summary, the current data indicate that PLD isozymes can down-regulate CKII activity through the acceleration of $CKII{\beta}$ degradation by ubiquitin-proteasome machinery.

Circadian Clock Gene Per1 Mediates BMP2-induced Osteoblast Differentiation in MC3T3-E1 Cells (MC3T3-E1 세포에서 BMP2에 의한 조골세포의 분화에 일주기 유전자 Per1이 미치는 영향)

  • Min, Hyeon-Young;Jang, Won-Gu
    • Journal of Life Science
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    • v.27 no.5
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    • pp.501-508
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    • 2017
  • Bone morphogenetic proteins (BMPs) are multifunctional cytokines that play important roles in a variety of cellular functions. Among BMP family members, BMP2 efficiently promotes osteoblast differentiation through Smad-mediated runt-related transcription factor 2 (Runx2) expression. Several recent studies suggest that BMPs are associated with clock genes, in particular Bmal1. Bmal1 protein heterodimerizes with Clock protein and then induces period 1 (Per1) expression. However, the role of Per1 on osteoblast differentiation remains unclear. In this study, we investigated whether Per1 is involved in osteoblast differentiation. MC3T3-E1 cells were treated with BMP2 for induction of osteoblastic differentiation. Osteogenic maker gene and Per1 mRNA expression were measured using real-time PCR. Interestingly, BMP2 treatment induced Per1 mRNA expression in MC3T3-E1 cells. To further investigate the function of Per1 on osteoblast differentiation, MC3T3-E1 cells were transiently transfected with pCMV-Per1. Per1 overexpression increased Runx2 mRNA and protein levels. Also, mRNA expression and promoter activity of osteocalcin were upregulated by Per1 overexpression. To investigate the effect of interaction between Per1 and osteogenic condition, MC3T3-E1 cells were cultured in osteogenic medium containing ascorbic acid and ${\beta}$-glycerophosphate. Osteogenic medium-induced ALP staining level and mineralization were synergistically increased by overexpression of Per1. Taken together, these results demonstrate that Per1 is a positive regulator of osteoblast differentiation.

Genetic Screening of the Dazl-Interacting Protein Genes

  • Lee, Kyung-Ho;Lee, Seong-Ju;Rhee, Kun-Soo
    • Animal cells and systems
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    • v.10 no.4
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    • pp.227-231
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    • 2006
  • Micro-deletions at specific loci of the Y chromosome have been observed frequently in male infertility patients, suggesting that genes in these regions are involved in male germ cell development. DAZ is a representative male infertility gene at the AZFc locus of the Y chromosome. Since DAZ contains an RNA binding motif along with so-called a DAZ domain, it was proposed to participate in RNA metabolism during spermatogenesis. A mouse gene homologous to the human DAZ gene has been cloned and named Dazl (DAZlike). Dazl is autosomal and expressed in the testis and also at a low level in the ovary. Male mice homozygous for the Dazl null allele have small testes with a few spermatogonia and almost complete absence of germ cells beyond the spermatogonial stage, suggesting the requirement of Dazl for entry or progression through meiosis. However, its exact cellular functions have not been understood yet. In order to investigate cellular functions of Dazl, we decided to isolate candidate interacting protein genes of the mouse Dazl, using yeast two-hybrid screening. A number of candidate Dazlinteracting proteins have been isolated, such as Bprp, Acf, Hgs, Murr1, Nbak3 and Ranbp9, but dynein light chain 1 (Dlc1) was most predominant. A strong interaction of Dazl with Dlc1 suggests that Dazl might function as an mRNA adaptor to the dynein motor complex.

LINC00703 Acts as a Tumor Suppressor via Regulating miR-181a/KLF6 Axis in Gastric Cancer

  • Yang, Haiyang;Peng, Minqi;Li, Yanjiao;Zhu, Renjie;Li, Xiang;Qian, Zhengjiang
    • Journal of Gastric Cancer
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    • v.19 no.4
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    • pp.460-472
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    • 2019
  • Purpose: Long noncoding RNA 00703 (LINC00703) was found originating from a region downstream of Kruppel-like factor 6 (KLF6) gene, having 2 binding sites for miR-181a. Since KLF6 has been reported as a target of miR-181a in gastric cancer (GC), this study aims to investigate whether LINC00703 regulates the miR-181a/KLF6 axis and plays a functional role in GC pathogenesis. Materials and Methods: GC tissues, cell lines, and nude mice were included in this study. RNA binding protein immunoprecipitation (RIP) and pull-down assays were used to evaluate interaction between LINC00703 and miR-181a. Quantitative real-time polymerase chain reaction and western blot were applied for analysis of gene expression at the transcriptional and protein levels. A nude xenograft mouse model was used to determine LINC00703 function in vivo. Results: We revealed that LINC00703 competitively interacts with miR-181a to regulate KLF6. Overexpression of LINC00703 inhibited cell proliferation, migration/invasion, but promoted apoptosis in vitro, and arrested tumor growth in vivo. LINC00703 expression was found to be decreased in GC tissues, which was positively correlated with KLF6, but negatively with the miR-181a levels. Conclusions: LINC00703 may have an anti-cancer function via modulation of the miR-181a/KLF6 axis. This study also provides a new potential diagnostic marker and therapeutic target for GC treatment.

Anti-inflammatory effect of sulforaphane on LPS-stimulated RAW 264.7 cells and ob/ob mice

  • Ranaweera, Sachithra S.;Dissanayake, Chanuri Y.;Natraj, Premkumar;Lee, Young Jae;Han, Chang-Hoon
    • Journal of Veterinary Science
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    • v.21 no.6
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    • pp.91.1-91.15
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    • 2020
  • Background: Sulforaphane (SFN) is an isothiocyanate compound present in cruciferous vegetables. Although the anti-inflammatory effects of SFN have been reported, the precise mechanism related to the inflammatory genes is poorly understood. Objectives: This study examined the relationship between the anti-inflammatory effects of SFN and the differential gene expression pattern in SFN treated ob/ob mice. Methods: Nitric oxide (NO) level was measured using a Griess assay. The inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) expression levels were analyzed by Western blot analysis. Pro-inflammatory cytokines (tumor necrosis factor [TNF]-α, interleukin [IL]-1β, and IL-6) were measured by enzyme-linked immunosorbent assay (ELISA). RNA sequencing analysis was performed to evaluate the differential gene expression in the liver of ob/ob mice. Results: The SFN treatment significantly attenuated the iNOS and COX-2 expression levels and inhibited NO, TNF-α, IL-1β, and IL-6 production in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells. RNA sequencing analysis showed that the expression levels of 28 genes related to inflammation were up-regulated (> 2-fold), and six genes were down-regulated (< 0.6-fold) in the control ob/ob mice compared to normal mice. In contrast, the gene expression levels were restored to the normal level by SFN. The protein-protein interaction (PPI) network showed that chemokine ligand (Cxcl14, Ccl1, Ccl3, Ccl4, Ccl17) and chemokine receptor (Ccr3, Cxcr1, Ccr10) were located in close proximity and formed a "functional cluster" in the middle of the network. Conclusions: The overall results suggest that SFN has a potent anti-inflammatory effect by normalizing the expression levels of the genes related to inflammation that were perturbed in ob/ob mice.

Fatty Acid Binding Protein 5 (FABP5) Promotes Aggressiveness of Gastric Cancer Through Modulation of Tumor Immunity

  • Mei-qing Qiu;Hui-jun Wang;Ya-fei Ju;Li Sun;Zhen Liu;Tao Wang;Shi-feng Kan;Zhen Yang;Ya-yun Cui;You-qiang Ke;Hong-min He;Shu Zhang
    • Journal of Gastric Cancer
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    • v.23 no.2
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    • pp.340-354
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    • 2023
  • Purpose: Gastric cancer (GC) is the second most lethal cancer globally and is associated with poor prognosis. Fatty acid-binding proteins (FABPs) can regulate biological properties of carcinoma cells. FABP5 is overexpressed in many types of cancers; however, the role and mechanisms of action of FABP5 in GC remain unclear. In this study, we aimed to evaluate the clinical and biological functions of FABP5 in GC. Materials and Methods: We assessed FABP5 expression using immunohistochemical analysis in 79 patients with GC and evaluated its biological functions following in vitro and in vivo ectopic expression. FABP5 targets relevant to GC progression were determined using RNA sequencing (RNA-seq). Results: Elevated FABP5 expression was closely associated with poor outcomes, and ectopic expression of FABP5 promoted proliferation, invasion, migration, and carcinogenicity of GC cells, thus suggesting its potential tumor-promoting role in GC. Additionally, RNA-seq analysis indicated that FABP5 activates immune-related pathways, including cytokine-cytokine receptor interaction pathways, interleukin-17 signaling, and tumor necrosis factor signaling, suggesting an important rationale for the possible development of therapies that combine FABP5-targeted drugs with immunotherapeutics. Conclusions: These findings highlight the biological mechanisms and clinical implications of FABP5 in GC and suggest its potential as an adverse prognostic factor and/or therapeutic target.