Publications by authors named "Sun-Yong Kim"

The effects of ultraviolet (UV) radiation on brain function have previously been investigated; however, the specific neurotransmitter-mediated mechanisms responsible for UV radiation-induced neurobehavioral changes remain elusive. In this study, we aimed to explore the mechanisms underlying UV radiation-induced neurobehavioral changes. In a mouse model, we observed that UV irradiation of the skin induces deficits in hippocampal memory, synaptic plasticity, and adult neurogenesis, as well as increased dopamine levels in the skin, adrenal glands, and brain.

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Multiple brain regions are engaged in classical fear conditioning. Despite evidence for cerebellar involvement in fear conditioning, the mechanisms by which cerebellar outputs modulate fear learning and memory remain unclear. We identify a population of deep cerebellar nucleus (DCN) neurons with monosynaptic glutamatergic projections to the lateral parabrachial nucleus (lPBN) (DCN neurons) in mice.

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Poly[(R)-3-hydroxybutyrate-co-(R)-3-hydroxyhexanoate] [P(3HB-co-3HHx)] has a high potential to serve as a commercial bioplastic due to its biodegradability, thermoplastic and mechanical properties. The properties of this copolymer are greatly affected by the composition of 3HHx monomer. One of the most efficient ways to modulate the composition of 3HHx monomer in P(3HB-co-3HHx) is by manipulating the (R)-3HHx-CoA monomer supply.

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Glutamine synthetase (GS) is a decameric enzyme that plays a key role in nitrogen metabolism. Acetylation of the N-terminal degron (N-degron) of GS is essential for ubiquitylation and subsequent GS degradation. The full-length GS structure showed that the N-degron is buried inside the GS decamer and is inaccessible to the acetyltransferase.

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Vesicle amine transport protein-1 (VAT-1) has been implicated in the regulation of vesicular transport, mitochondrial fusion, phospholipid transport and cell migration, and is a potential target of anticancer drugs. Little is known about the molecular function of VAT-1. The amino acid sequence indicates that VAT-1 belongs to the quinone oxidoreductase subfamily, suggesting that VAT-1 may possess enzymatic activity in unknown redox processes.

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Biodegradable polyester polyhydroxyalkanoate (PHA) is a promising bioplastic material for industrial use as a replacement for petroleum-based plastics. PHA synthase PhaC forms an active dimer to polymerize acyl moieties from the substrate acyl-coenzyme A (CoA) into PHA polymers. Here we present the crystal structure of the catalytic domain of PhaC from Chromobacterium sp.

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AKT/PKB is downregulated by the ubiquitin-proteasome system (UPS), which plays a key role in cell survival and tumor progression in various types of cancer. The objective of this study was to determine the relationship between the sequential ubiquitination of lysine residues K284 to K214 in AKT and R-HSPA5 (the arginylated form of HSPA5), which contribute to the autophagic/lysosomal degradation of AKT when impaired proteasomal activity induces cellular stress. Results show that proteasome inhibitors (PIs) increased ATE1 (arginyltransferase 1)-mediated R-HSPA5 levels in a reactive oxygen species (ROS)-dependent manner.

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SHP2 is an unusual protein phosphatase that functions as an activator for several signaling pathways, including the RAS pathway, while most other phosphatases suppress their downstream signaling cascades. The physiological and pathophysiological roles of SHP2 have been extensively studied in the field of cancer research. Mutations in the gene which encodes SHP2 are also highly associated with developmental disorders, such as Noonan syndrome (NS), and cognitive deficits including learning disabilities are common among NS patients.

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Non-thermal plasma (NTP) has been studied as a novel therapeutic tool for cancer that does not damage healthy cells. In this study, we show that NTP-treated solutions (NTS) can induce death in various leukemia cells through mechanistic target of rapamycin (mTOR) ubiquitination. Previously, we manufactured and demonstrated the efficacy of NTS in solid cancers.

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The GST pull-down assay is an intuitive and fast in vitro method for analyzing protein-protein or protein-ligand interactions and is comprised of a "bait" which is a GST-fused protein expressed in E. coli host or a baculovirus expression system and a "prey" which comprises putative binding partner protein(s) or other ligand molecule(s). This method is suitable for examining the direct interaction between two purified proteins and estimating the extent of the affinity.

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AKT (also known as protein kinase B, PKB) plays an important role in cell survival or tumor progression. For these reasons, AKT is an emerging target for cancer therapeutics. Previously our studies showed that mitochondrial E3 ubiquitin protein ligase 1 (MUL1, also known as MULAN/GIDE/MAPL) is suppressed in head and neck cancer (HNC) and acts as negative regulator against AKT.

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Background And Purpose: This study was to evaluate the diagnostic value of improved motion-sensitized driven-equilibrium (iMSDE)-prepared 3D T1-weighted magnetic resonance imaging (MRI) (iMSDE-3DMRI) in intracranial vertebrobasilary dissection (VBD) and to compare iMSDE-3DMRI images with those obtained using 2D high-resolution (HR) MRI with respect to their diagnostic performance in VBD.

Materials And Methods: We retrospectively reviewed 105 lesions from 102 patients who underwent multimodal imaging and contrast-enhanced iMSDE-3DMRI (CE-iMSDE-3DMRI). The 2D-HRMRI protocol comprised four axial HR images.

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HSPA5/GRP78/BiP plays an important role in cell survival or tumor progression. For these reasons, HSPA5 is an emerging therapeutic target in cancer development. Here we report that HSPA5 contributes to head and neck cancer (HNC) survival via maintenance of lysosomal activity; however, a nonthermal plasma (NTP, considered as a next-generation cancer therapy)-treated solution (NTS) inhibits HNC progression through HSPA5-dependent alteration of lysosomal activity.

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A viral responsive protein 15 from Penaeus monodon (PmVRP15) has been reported to be important for white spot syndrome virus (WSSV) infection in vivo. This work aims to characterize PmVRP15 and investigate its possible role in nuclear import/export of the virus. Circular dichroism spectra showed that PmVRP15 contains high helical contents (82%).

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Polyhydroxyalkanoate (PHA) is a promising candidate for use as an alternative bioplastic to replace petroleum-based plastics. Our understanding of PHA synthase PhaC is poor due to the paucity of available three-dimensional structural information. Here we present a high-resolution crystal structure of the catalytic domain of PhaC from Chromobacterium sp.

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Patients who have large cerebral infarctions may not be good candidates for endovascular treatment. Various methods for determining infarct volume have been used in clinical studies. We evaluated the effectiveness of several methods for measuring infarct volume, especially regarding futile outcomes despite endovascular treatment.

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MOB1 protein is a key regulator of large tumor suppressor 1/2 (LATS1/2) kinases in the Hippo pathway. MOB1 is present in an autoinhibited form and is activated by MST1/2-mediated phosphorylation, although the precise mechanisms responsible for autoinhibition and activation are unknown due to lack of an autoinhibited MOB1 structure. Here, we report on the crystal structure of full-length MOB1B in the autoinhibited form and a complex between the MOB1B core domain and the N-terminal regulation (NTR) domain of LATS1.

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Background And Purpose: The outcomes of acute internal carotid artery (ICA) terminus occlusions are poor. We classified ICA terminus occlusions into 2 groups according to the occlusion pattern of the circle of Willis and hypothesized that clinical outcomes would significantly differ between them.

Methods: Consecutive patients with acute ICA terminus occlusions evaluated by baseline computed tomographic angiography were enrolled.

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This study aimed to investigate the relationships among parameters from dynamic contrast-enhanced (DCE) MRI, diffusion-weighted MRI (DWI), and F-fluorodeoxyglucose (F-FDG) PET in patients with primary head-and-neck squamous cell carcinoma (HNSCC).A total of 34 patients with primary HNSCC underwent DCE-MRI, DWI, and F-FDG PET before treatment. The perfusion parameters (Ktrans, Ktransmax, Kep, Ve, Vp, and AUC60) from DCE-MRI and ADC (ADCmean, ADCmin) values from DWI were calculated within the manually placed ROI around the main tumor.

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Background And Purpose: The goal of stent retriever-based thrombectomy is removal of embolic clots in patients with intracranial large artery occlusion. However, outcomes of stent retrieval may differ between acute arterial occlusions due to intracranial atherosclerotic disease (IAD) and those due to embolism. This case series describes the outcomes of stent retriever-based thrombectomy and rescue treatments in 9 patients with IAD-related occlusion.

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Recent research on non-thermal plasma (NTP, an ionized gas) has identified it as a novel cancer therapeutic tool. However, the molecular mechanism remains unclear. In this study, we demonstrated NTP induced cell death of head and neck cancer (HNC) through the AKT ubiquitin-proteasome system.

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By virtue of the critical roles of Akt in vascular endothelial cell (EC) survival and function, cigarette smoke-induced Akt reduction may contribute to EC death and dysfunction in smokers' lungs. One of the negative Akt regulatory mechanisms is K48-linked Akt ubiquitination and subsequent proteasomal degradation. Here, we assessed the involvement of mitochondrial E3 ubiquitin protein ligase 1 (MUL1), recently revealed as a novel Akt ubiquitin E3 ligase, in cigarette smoke-induced Akt ubiquitination and its contribution to pulmonary EC death and dysfunction.

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We show that ATE1-encoded Arg-transfer RNA transferase (R-transferase) of the N-end rule pathway mediates N-terminal arginylation of multiple endoplasmic reticulum (ER)-residing chaperones, leading to their cytosolic relocalization and turnover. N-terminal arginylation of BiP (also known as GRP78), protein disulphide isomerase and calreticulin is co-induced with autophagy during innate immune responses to cytosolic foreign DNA or proteasomal inhibition, associated with increased ubiquitylation. Arginylated BiP (R-BiP) is induced by and associated with cytosolic misfolded proteins destined for p62 (also known as sequestosome 1, SQSTM1) bodies.

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Although obesity is clearly identified as a risk factor for diabetes, the relationship between diabetes and metabolically healthy status of obesity is less clear. This study was aimed to evaluate the incidental risk of diabetes according to metabolically healthy status of obesity. 31,834 Korean men without diabetes categorized into six groups according to their metabolically healthy status stratified by degree of obesity were followed up for 5 years: metabolically healthy normal weight (MH-NW), metabolically healthy overweight (MH-OW), metabolically healthy obese (MHO), metabolically unhealthy normal weight (MU-NW), metabolically unhealthy overweight (MU-OW), and metabolically unhealthy obese (MUO).

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