• BMB Reports
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• v.42 no.1
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• pp.1-5
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• 2009

Synaptic vesicles (SVs) are key structures for synaptic transmission in neurons. Numerous membrane-associated proteins are sorted from the Golgi complex to the axon and the presynaptic terminal. Protein-protein and protein-lipid interactions are involved with SV targeting in neurons. Interestingly, many SV proteins have lipid binding capability, primarily with either cholesterol or phosphoinositides (PIs). As examples, the major SV protein synaptophysin can bind to cholesterol, a major lipid component in SVs, while several other SV proteins, including synaptotagmin, can bind to PIs. Thus, lipid-protein binding plays a key role for the SV targeting of synaptic proteins. In addition, numerous SV proteins can be palmitoylated. Palmitoylation is thought to be another synaptic targeting signal. Here, we briefly describe the relationship between lipid binding and SV targeting.

• BMB Reports
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• v.34 no.2
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• pp.118-122
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• 2001

The translocation of ribose-binding protein (RBP) into the inverted membrane vesicles (IMV) of Escherichia coli and eukaryotic microsomes was studied using the in vitro translation/translocation system. It was found that RBP was translocated into heterologous eukaryotic microsomes co-translationally, as well as post-translationally However, RBP was translocated only past-translationally into IMV. Degradation fragments of RBP with the molar mass of 14 and 16 kDa were produced during the translocation into IMV However, the amount of the degradation products decreased and the mature form of RBP appeared in the presence of phenylmethylsulfonyl fluoride (PMSF). PMSF and GTP accelerated the translocation of RBF It was also found that SecB enhanced the post-translational translocation of RBP It appears that RBP is translocated via at least two targeting paths.

• Biomolecules & Therapeutics
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• v.31 no.4
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• pp.434-445
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• 2023

We investigated whether FTY-720 might have an effect on bleomycin-induced pulmonary fibrosis through inhibiting TGF-β1 pathway, and up-regulating autophagy. The pulmonary fibrosis was induced by bleomycin. FTY-720 (1 mg/kg) drug was intraperitoneally injected into mice. Histological changes and inflammatory factors were observed, and EMT and autophagy protein markers were studied by immunohistochemistry and immunofluorescence. The effects of bleomycin on MLE-12 cells were detected by MTT assay and flow cytometry, and the related molecular mechanisms were studied by Western Blot. FTY-720 considerably attenuated bleomycin-induced disorganization of alveolar tissue, extracellular collagen deposition, and α-SMA and E-cadherin levels in mice. The levels of IL-1β, TNF-α, and IL-6 cytokines were attenuated in bronchoalveolar lavage fluid, as well as protein content and leukocyte count. COL1A1 and MMP9 protein expressions in lung tissue were significantly reduced. Additionally, FTY-720 treatment effectively inhibited the expressions of key proteins in TGF-β1/TAK1/P38MAPK pathway and regulated autophagy proteins. Similar results were additionally found in cellular assays with mouse alveolar epithelial cells. Our study provides proof for a new mechanism for FTY-720 to suppress pulmonary fibrosis. FTY-720 is also a target for treating pulmonary fibrosis.

• Experimental and Molecular Medicine
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• v.50 no.11
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• pp.12.1-12.12
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• 2018

Drugs targeting the epidermal growth factor receptor (EGFR), such as cetuximab and panitumumab, have been prescribed for metastatic colorectal cancer (CRC), but patients harboring KRAS mutations are insensitive to them and do not have an alternative drug to overcome the problem. The levels of ${\beta}$-catenin, EGFR, and RAS, especially mutant KRAS, are increased in CRC patient tissues due to mutations of adenomatous polyposis coli (APC), which occur in 90% of human CRCs. The increases in these proteins by APC loss synergistically promote tumorigenesis. Therefore, we tested KYA1797K, a recently identified small molecule that degrades both ${\beta}$-catenin and Ras via $GSK3{\beta}$ activation, and its capability to suppress the cetuximab resistance of KRAS-mutated CRC cells. KYA1797K suppressed the growth of tumor xenografts induced by CRC cells as well as tumor organoids derived from CRC patients having both APC and KRAS mutations. Lowering the levels of both ${\beta}$-catenin and RAS as well as EGFR via targeting the $Wnt/{\beta}$-catenin pathway is a therapeutic strategy for controlling CRC and other types of cancer with aberrantly activated the $Wnt/{\beta}$-catenin and EGFR-RAS pathways, including those with resistance to EGFR-targeting drugs attributed to KRAS mutations.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.8
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• pp.3905-3909
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• 2012

Ovarian cancer is the fifth leading cause of cancer death in women aged 35 to 74 years. Although there are several popular hypothesis of ovarian cancer pathogenesis, the genetic mechanisms are far from being clear. Recently, systems biology approaches such as network-based methods have been successfully applied to elucidate the mechanisms of diseases. In this study, we constructed a crosstalk network among ovarian cancer related pathways by integrating protein-protein interactions and KEGG pathway information. Several significant pathways were identified to crosstalk with each other in ovarian cancer, such as the chemokine, Notch, Wnt and NOD-like receptor signaling pathways. Results from these studies will provide the groundwork for a combination therapy approach targeting multiple pathways which will likely be more effective than targeting one pathway alone.

• Molecules and Cells
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• v.46 no.6
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• pp.348-350
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• 2023

• BMB Reports
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• v.50 no.11
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• pp.554-559
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• 2017

MicroRNAs (miRNAs) are ~22nt-long single-stranded RNA molecules that form a RNA-induced silencing complex with Argonaute (AGO) protein to post-transcriptionally downregulate their target messenger RNAs (mRNAs). To understand the regulatory mechanisms of miRNA, discovering the underlying functional rules for how miRNAs recognize and repress their target mRNAs is of utmost importance. To determine functional miRNA targeting rules, previous studies extensively utilized various methods including high-throughput biochemical assays and bioinformatics analyses. However, targeting rules reported in one study often fail to be reproduced in other studies and therefore the general rules for functional miRNA targeting remain elusive. In this review, we evaluate previously-reported miRNA targeting rules and discuss the biological impact of the functional miRNAs on gene-regulatory networks as well as the future direction of miRNA targeting research.

• Molecules and Cells
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• v.46 no.1
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• pp.21-32
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• 2023

MicroRNAs (miRNAs) play cardinal roles in regulating biological pathways and processes, resulting in significant physiological effects. To understand the complex regulatory network of miRNAs, previous studies have utilized massivescale datasets of miRNA targeting and attempted to computationally predict the functional targets of miRNAs. Many miRNA target prediction tools have been developed and are widely used by scientists from various fields of biology and medicine. Most of these tools consider seed pairing between miRNAs and their mRNA targets and additionally consider other determinants to improve prediction accuracy. However, these tools exhibit limited prediction accuracy and high false positive rates. The utilization of additional determinants, such as RNA modifications and RNA-binding protein binding sites, may further improve miRNA target prediction. In this review, we discuss the determinants of functional miRNA targeting that are currently used in miRNA target prediction and the potentially predictive but unappreciated determinants that may improve prediction accuracy.

• Biomolecules & Therapeutics
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• v.24 no.5
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• pp.453-468
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• 2016

There is a conserved ATPase domain in topoisomerase II (topo II) and heat shock protein 90 (Hsp90) which belong to the GHKL (gyrase, Hsp90, histidine kinase, and MutL) family. The inhibitors that target each of topo II and Hsp90 are intensively studied as anti-cancer drugs since they play very important roles in cell proliferation and survival. Therefore the development of dual targeting anti-cancer drugs for topo II and Hsp90 is suggested to be a promising area. The topo II and Hsp90 inhibitors, known to bind to their ATP binding site, were searched. All the inhibitors investigated were docked to both topo II and Hsp90. Four candidate compounds as possible dual inhibitors were selected by analyzing the molecular docking study. The pharmacophore model of dual inhibitors for topo II and Hsp90 were generated and the design of novel dual inhibitor was proposed.

• Biomolecules & Therapeutics
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• v.4 no.4
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• pp.398-401
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• 1996

The glucose transporters found in the plasma membrane of all animal cells are known to have 12 putative transmembrane domains. Among 7 cytoplasmic loops, the fourth loop is the largest one. Since previous studies showed that cofilin, an actin-modulating protein, was found to interact with the largest cytoplasmic loop of (Na, K)ATPase, we tested if cofilin interacts with the largest cytoplasmic loop of Glut4. We demonstrated by the two-hybrid system that the largest cytoplasmic loop of Glut4 did not show any interaction with cofilin, suggesting that cofilin is not required for the membrane targeting process of other membrane proteins but only for a P-type ATPase.