• Journal of Applied Biological Chemistry
• /
• v.58 no.3
• /
• pp.201-208
• /
• 2015

The role of RNA-binding proteins (RBPs) to regulate expression of genes seems to be very important. RBPs play important roles in RNA related bioprocess such as transcription, pre-mRNA splicing, polyadenylation, transport, localization, translation, turn over and maintenance of structure. Despite of many researches on RNA binding proteins, detailed mechanisms of these proteins have not been fully understood. It seems that many parts of RBPs remains unknown and should be characterized for the better understanding of gene expression. Recently, genetic, biochemical, and bioinformatic analysis of genomes revealed a vast array of RBPs and many parts are interesting to understand bioprocessing including gene expression.

• BMB Reports
• /
• v.48 no.5
• /
• pp.239-240
• /
• 2015

Dysregulation of cytokine expression causes inflammatory diseases or chronic infection conditions. We have identified that Tat-activating regulatory DNA-binding protein-43 (TDP-43) is involved in cytokine RNA processing in order to promote an optimal immune response. The interaction of TDP-43 with spliceosomal components from the Cajal body leads to the formation of a novel sub-nuclear body called the Interleukin (IL)-6 and IL-10 Splicing Activating Compartment (InSAC). TDP-43 binds to the IL-6 and IL-10 RNAs in a sequence-dependent manner. In cell-based studies, we observed that lipopoly-saccharide (LPS) stimulation induces the formation of the InSAC through TDP-43 ubiquitination, thereby influencing the processing and expression levels of IL-6 RNA. Moreover, TDP-43 knockdown in vivo results in a decrease in IL-6 production and its RNA splicing and stability. Thus, these findings demonstrate that the InSAC is linked to the activation and modulation of the immune response. [BMB Reports 2015; 48(5): 239-240]

• BMB Reports
• /
• v.52 no.12
• /
• pp.671-678
• /
• 2019

The random V(D)J recombination process ensures the diversity of the primary immunoglobulin (Ig) repertoire. In two thirds of cases, imprecise recombination between variable (V), diversity (D), and joining (J) segments induces a frameshift in the open reading frame that leads to the appearance of premature termination codons (PTCs). Thus, many B lineage cells harbour biallelic V(D)J-rearrangements of Ig heavy or light chain genes, with a productively-recombined allele encoding the functional Ig chain and a nonproductive allele potentially encoding truncated Ig polypeptides. Since the pattern of Ig gene expression is mostly biallelic, transcription initiated from nonproductive Ig alleles generates considerable amounts of primary transcripts with out-of-frame V(D)J junctions. How RNA surveillance pathways cooperate to control the noise from nonproductive Ig genes will be discussed in this review, focusing on the benefits of nonsense- mediated mRNA decay (NMD) activation during B-cell development and detrimental effects of nonsense-associated altered splicing (NAS) in terminally differentiated plasma cells.

• BMB Reports
• /
• v.44 no.11
• /
• pp.725-729
• /
• 2011

We report a novel mechanism of a CDH1 splicing mutation in a patient with signet ring cell carcinoma of the stomach. A 27-year-old man complaining of aggravated dyspepsia was diagnosed with signet ring cell carcinoma. Both his father and uncle had died of stomach cancer at a young age. DNA sequencing analysis of the CDH1 gene revealed a splice site mutation (c.833-2A>G). By RNA/cDNA sequencing analysis, CDH1 c.833-2A>G generated a new acceptor site within intron 6, causing the insertion of a 79-bp intronic sequence between exon 6 and 7 (r.833-79_833-1ins), and resulting in a frame shift. E-cadherin immunohistochemical staining revealed a loss of CDH1 expression. This study reveals the disease-causing mechanism of this splicing mutation, and emphasizes the need for functional studies using RNA samples for the accurate interpretation of detected splicing variant. This is the first reported case of a CDH1 mutation in a Korean patient.

• The Zoological Society Korea : Newsletter
• /
• v.17 no.1
• /
• pp.22-30
• /
• 2000

• Journal of Life Science
• /
• v.19 no.4
• /
• pp.549-552
• /
• 2009

Genetic mutations by gene fusion result from chromosomal rearrangement, trans-splicing, and intergenic splicing. Trans-splicing is a phenomenon in which two pre-mRNAs grow together into one. We analyzed the trans-splicing products in embryonic stem cells. By using bioinformatic tools, 70 trans-splicing transcripts were identified. They are classified into 6 types according to fusion pattern: 5'UTR-5'UTR, 5'UTR-3'UTR, 3'UTR-3'UTR, 5'UTR-CDS, 3'UTR-CDS, CDS-CDS. The fusion products are more abundant in CDS regions than in UTR regions, which contain multiple intron numbers. Chromosome analysis showing gene fusion via trans-splicing indicated that chromosomes 17 and 19 were activated. These data are of great use for further studies in relation to fusion genes and human diseases.

• Asian-Australasian Journal of Animal Sciences
• /
• v.32 no.8
• /
• pp.1095-1103
• /
• 2019

Objective: Among stress responses, the unfolded protein response (UPR) is a well-known mechanism related to endoplasmic reticulum (ER) stress. ER stress is induced by a variety of external and environmental factors such as starvation, ischemia, hypoxia, oxidative stress, and heat stress. Inositol requiring enzyme $1{\alpha}$ ($IRE1{\alpha}$)-X-box protein 1 (XBP1) is the most conserved pathway involved in the UPR and is the main component that mediates $IRE1{\alpha}$ signalling to downstream ER-associated degradation (ERAD)- or UPR-related genes. XBP1 is a transcription factor synthesised via a novel mechanism called 'frame switch splicing', and this process has not yet been studied in the horse XBP1 gene. Therefore, the aim of this study was to confirm the frame switch splicing of horse XBP1 and characterise its dynamics using Thoroughbred muscle cells exposed to heat stress. Methods: Primary horse muscle cells were used to investigate heat stress-induced frame switch splicing of horse XBP1. Frame switch splicing was confirmed by sequencing analysis. XBP1 amino acid sequences and promoter sequences of various species were aligned to confirm the sequence homology and to find conserved cis-acting elements, respectively. The expression of the potential XBP1 downstream genes were analysed by quantitative real-time polymerase chain reaction. Results: We confirmed that splicing of horse XBP1 mRNA was affected by the duration of thermal stress. Twenty-six nucleotides in the mRNA of XBP1 were deleted after heat stress. The protein sequence and the cis-regulatory elements on the promoter of horse XBP1 are highly conserved among the mammals. Induction of putative downstream genes of horse XBP1 was dependent on the duration of heat stress. We confirmed that both the mechanisms of XBP1 frame switch splicing and various binding elements found in downstream gene promoters are highly evolutionarily conserved. Conclusion: The frame switch splicing of horse XBP1 and its dynamics were highly conserved among species. These results facilitate studies of ER-stress in horse.

• Tuberculosis and Respiratory Diseases
• /
• v.84 no.1
• /
• pp.55-66
• /
• 2021

Background: Particulate matter 10 (PM₁₀; airborne particles <10 ㎛) inhalation has been demonstrated to induce airway and lung diseases. In this study, we investigate the effects of PM₁₀ inhalation on RNA expression in lung tissues using a murine model. Methods: Female BALB/c mice were affected with PM₁₀, ovalbumin (OVA), or both OVA and PM₁₀. PM₁₀ was administered intranasally while OVA was both intraperitoneally injected and intranasally administered. Treatments occurred 4 times over a 2-week period. Two days after the final challenges, mice were sacrificed. Full RNA sequencing using lung homogenates was conducted. Results: While PM₁₀ did not induce cell proliferation in bronchoalveolar fluid or lead to airway hyper-responsiveness, it did cause airway inflammation and lung fibrosis. Levels of interleukin 1β, tumor necrosis factor-α, and transforming growth factor-β in lung homogenates were significantly elevated in the PM₁₀-treated group, compared to the control group. The PM₁₀ group also showed increased RNA expression of Rn45a, Snord22, Atp6v0c-ps2, Snora28, Snord15b, Snora70, and Mmp12. Generally, genes associated with RNA splicing, DNA repair, the inflammatory response, the immune response, cell death, and apoptotic processes were highly expressed in the PM₁₀-treated group. The OVA/PM₁₀ treatment did not produce greater effects than OVA alone. However, the OVA/PM₁₀-treated group did show increased RNA expression of Clca1, Snord22, Retnla, Prg2, Tff2, Atp6v0c-ps2, and Fcgbp when compared to the control groups. These genes are associated with RNA splicing, DNA repair, the inflammatory response, and the immune response. Conclusion: Inhalation of PM₁₀ extensively altered RNA expression while also inducing cellular inflammation, fibrosis, and increased inflammatory cytokines in this murine mouse model.

• BMB Reports
• /
• v.55 no.7
• /
• pp.348-353
• /
• 2022

Gastrointestinal cancer is associated with a high mortality rate. Here, we report that the splice variant of NRP/B contributes to tumorigenic activity in highly malignant gastric cancer through dissociation from the tumor repressor, HDAC5. NRP/B mRNA expression is significantly higher in the human gastric cancer tissues than in the normal tissues. Further, high levels of both the NRP/B splice variant and Lgr5, but not the full-length protein, are found in highly tumorigenic gastric tumor cells, but not in non-tumorigenic cells. The loss of NRP/B markedly inhibits cell migration and invasion, which reduces tumor formation in vivo. Importantly, the inhibition of alternative splicing increases the levels of NRP/B-1 mRNA and protein in AGS cells. The ectopic expression of full-length NRP/B exhibits tumor-suppressive activity, whereas NRP/B-2 induces the noninvasive human gastric cancer cells tumorigenesis. The splice variant NRP/B-2 which loses the capacity to interact with tumor repressors promoted oncogenic activity, suggesting that the BTB/POZ domain in the N-terminus has a crucial role in the suppression of gastric cancer. Therefore, the regulation of alternative splicing of the NRP/B gene is a potential novel target for the treatment of gastrointestinal cancer.

• Molecules and Cells
• /
• v.39 no.3
• /
• pp.179-185
• /
• 2016

Posttranscriptional regulation of RNA metabolism, including RNA processing, intron splicing, editing, RNA export, and decay, is increasingly regarded as an essential step for fine-tuning the regulation of gene expression in eukaryotes. RNA-binding proteins (RBPs) are central regulatory factors controlling posttranscriptional RNA metabolism during plant growth, development, and stress responses. Although functional roles of diverse RBPs in living organisms have been determined during the last decades, our understanding of the functional roles of RBPs in plants is lagging far behind our understanding of those in other organisms, including animals, bacteria, and viruses. However, recent functional analysis of multiple RBP family members involved in plant RNA metabolism and elucidation of the mechanistic roles of RBPs shed light on the cellular roles of diverse RBPs in growth, development, and stress responses of plants. In this review, we will discuss recent studies demonstrating the emerging roles of multiple RBP family members that play essential roles in RNA metabolism during plant growth, development, and stress responses.