• BMB Reports
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• v.38 no.3
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• pp.259-265
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• 2005

Proteins must fold into their correct three-dimensional conformation in order to attain their biological function. Conversely, protein aggregation and misfolding are primary contributors to many devastating human diseases, such as prion-mediated infections, Alzheimer's disease, type II diabetes and cystic fibrosis. While the native conformation of a polypeptide is encoded within its primary amino acid sequence and is sufficient for protein folding in vitro, the situation in vivo is more complex. Inside the cell, proteins are synthesized or folded continuously; a process that is greatly assisted by molecular chaperones. Molecular chaperones re a group of structurally diverse and mechanistically distinct proteins that either promote folding or prevent the aggregation of other proteins. With our increasing understanding of the proteome, it is becoming clear that the number of proteins that can be classified as molecular chaperones is increasing steadily. Many of these proteins have novel but essential cellular functions that differ from that of more 'conventional' chaperones, such as Hsp70 and the GroE system. This review focuses on the emerging role of molecular chaperones in protein quality control, i.e. the mechanism that rids the cell of misfolded or incompletely synthesized polypeptides that otherwise would interfere with normal cellular function.

• Journal of fish pathology
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• v.17 no.3
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• pp.191-198
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• 2004

Temporal changes of plasma vitellogenin (VTG), alkaline-labile protein phosphorus (ALPP), calcium (Ca), glutamate pyruvate transaminase (GPT) and hepatosomatic index (HSI) were examined in the $estradiol-17\beta$ ${E_2}$-administered immature rockfish, Sebastes schlegeli. Fish were intraperitoneally injected with ${E_2}$ (5 ㎎/kg B.W.) in 70% ethanol and then plasma were extracted at 0, 1, 3, 6, 9, 12 and 15 days. VTG band was detected at a molecular weight position of about 170 kDa on Day 3 in SDS-PAGE. This band became more distinct at 6 days but its was gradually thinned with time-course, and not detected at 15 days. Plasma ALPP and Ca increased suddenly at 1 day and the highest concentrations were detected at 6 days and then these concentrations decreased gradually with time-course. ALPP and Ca concentrations at 15 days after E2 administration were very similar to that before E2 administration. GPT was increased at 1 day and higher GPT was detected at 3 days. However, GPT was gradually decreased with time-course. GPT and HSI at 15 days after E2 administration were also very similar to that before E2 administration. HSI was also increased at 1 day and the highest value was detected at 3 days and then gradually decreased with time-course. These results suggest that plasma ALPP, Ca, GPT and HSI could be utilized as a biomarker of exogenous E2 exposure in coastal ecosystem, because the changes of ALPP, Ca, GPT and HSI after E2 administration are very similar to that of VTG.

• International Journal of Oncology
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• v.56 no.6
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• pp.1509-1520
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• 2020

The phosphoinositide 3-kinase (PI3K) signaling pathway plays an important role in human cancer as it regulates critical cellular functions, such as survival, proliferation and metabolism. In the present study, a novel PI3Kα inhibitor (HS-146) was synthesized and its anticancer effects on MCF-7, MDA-MB-231, SKBR3 and BT-474 human breast cancer cell lines were confirmed. HS-146 was found to be most effective in inhibiting the proliferation of MCF-7 cells and in inducing cell cycle arrest in the G0/G1 phase by downregulating cyclin D1, cyclin E, cyclin-dependent kinase (Cdk)2 and Cdk4, and upregulating p21Waf1/Cip1 protein levels in this cell line. The induction of apoptosis by HS-146 was confirmed by DAPI staining and western blot analysis. Cell shrinkage and nuclear condensation, which are typical morphological markers of apoptosis, were increased by HS-146 in the MCF-7 cells in a concentration-dependent manner, and HS-146 also increased the protein expression levels of cleaved poly(ADP-ribose) polymerase (PARP) and decreased the protein expression levels of Mcl-1 and caspase-7. In addition, HS-146 effectively decreased the phosphorylation levels of downstream PI3K effectors, such as Akt, mammalian target of rapamycin (mTOR), glycogen synthase kinase 3β (GSK3β), p70S6K1 and eukaryotic translation initiation factor 4E-binding protein 1 (4E-BP1). Hypoxia-inducible factor (HIF)-1α and vascular endothelial growth factor (VEGF) expression were also suppressed by HS-146 under hypoxic conditions, and HS-146 inhibited the migration and invasion of MCF-7 cells in a concentration-dependent manner. On the whole, the findings of the present study suggest that HS-146, a novel PI3Kα inhibitor, may be an effective novel therapeutic candidate that suppresses breast cancer proliferation and metastasis by inhibiting the PI3K/Akt/mTOR pathway.

• 한국생물공학회:학술대회논문집
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• 2001.11a
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• pp.719-722
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• 2001

Silk proteins from Nephila clavipes are fibrous proteins containing repetitive sequences with both crystalline and amorphous domains. In order to obtain high-level production of silk protein, the synthetic genes had 16 contiguous units of the consensus repeat sequence of the silk protein were expressed in Escherichia coli BL21(DE3) under the strong inducible T7 promoter. For production of recombinant silk protein in large amounts, pH-stat fed-batch cultures were carried out. The recombinant silk protein was produced as soluble forms in E. coli, and the recombinant silk protein content was as high as 11% of the total protein. When cells were induced at $OD_{600}$ of 60, the amount of silk protein produced was 6.49 g/L. After simple purification steps, 9.2 mg of silk protein that was more than 80% pure was obtained from a 50 mL culture, and the recovery yield was 26.3%.

• Genomics & Informatics
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• v.18 no.4
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• pp.39.1-39.8
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• 2020

Alzheimer's disease (AD) is a chronic, progressive brain disorder that slowly destroys affected individuals' memory and reasoning faculties, and consequently, their ability to perform the simplest tasks. This study investigated the hub genes of AD. Proteins interact with other proteins and non-protein molecules, and these interactions play an important role in understanding protein function. Computational methods are useful for understanding biological problems, in particular, network analyses of protein-protein interactions. Through a protein network analysis, we identified the following top 10 hub genes associated with AD: PTGER3, C3AR1, NPY, ADCY2, CXCL12, CCR5, MTNR1A, CNR2, GRM2, and CXCL8. Through gene enrichment, it was identified that most gene functions could be classified as integral to the plasma membrane, G-protein coupled receptor activity, and cell communication under gene ontology, as well as involvement in signal transduction pathways. Based on the convergent functional genomics ranking, the prioritized genes were NPY, CXCL12, CCR5, and CNR2.

• Journal of the Korean Magnetic Resonance Society
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• v.21 no.2
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• pp.50-54
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• 2017

Cupin-superfamily proteins represent the most functionally diverse groups of proteins and include a huge number of functionally uncharacterized proteins. Recently, YaiE, a cupin protein from Escherichia coli has been suggested to be involved in a novel activity of pyrimidine/purine nucleoside phosphorylase (PPNP). In the present study, we achieved a complete backbone NMR assignments of YaiE, by a series of heteronuclear multidimensional NMR experiments on its [$^{13}C/^{15}N$]-enriched sample. Subsequently, secondary structure analysis using the assigned chemical shift values identified 10 obvious ${\beta}-strands$ and a tentative $3_{10}-helix$. Taken all together, the results constitute the first structural characterization of a putative PPNP cupin protein.

• Preventive Nutrition and Food Science
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• v.7 no.3
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• pp.299-304
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• 2002

Volatile flavor compounds in the headspace of swiss cheese whey protein concentrate (WPC) were analyzed by dynamic headspace analyzer, gas chromatography, and mass spectrometer. Sixty one compounds were detected from the headspace of dry WPC and 23 compounds from the headspace of an aqueous solution of WPC. The major components were propanol, hexanal, 2-butanone, 2-pentanone, 2,3-butanedion, 2-propanol, acetic acid, dimethyl disulfide and benzothiazole. An external dynamic headspace sampler, devised for this study, effectively collected volatiles from the headspace of dry WPC and aqueous WPC solutions.

• Molecules and Cells
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• v.47 no.1
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• pp.100001.1-100001.8
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• 2024

In eukaryotes, a primary protein quality control (PQC) process involves the destruction of conformationally misfolded proteins through the ubiquitin-proteasome system. Because approximately one-third of eukaryotic proteomes fold and assemble within the endoplasmic reticulum (ER) before being sent to their destinations, the ER plays a crucial role in PQC. The specific functions and biochemical roles of several E3 ubiquitin ligases involved in ER-associated degradation in mammals, on the other hand, are mainly unknown. We identified 2 E3 ligases, ubiquitin protein ligase E3 component N-recognin 1 (UBR1) and ubiquitin protein ligase E3 component N-recognin 2 (UBR2), which are the key N-recognins in the N-degron pathway and participate in the ER stress response in mammalian cells by modulating their stability. Cells lacking UBR1 and UBR2 are hypersensitive to ER stress-induced apoptosis. Under normal circumstances, these proteins are polyubiquitinated through Lys48-specific linkages and are then degraded by the 26S proteasome. In contrast, when cells are subjected to ER stress, UBR1 and UBR2 exhibit greater stability, potentially as a cellular adaptive response to stressful conditions. Although the precise mechanisms underlying these findings require further investigation, our findings show that cytoplasmic UBR1 and UBR2 have anti-ER stress activities and contribute to global PQC in mammals. These data also reveal an additional level of complexity within the mammalian ER-associated degradation system, implicating potential involvement of the N-degron pathway.

• Korean Journal of Veterinary Research
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• v.36 no.3
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• pp.577-598
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• 1996

This study was conducted to identify the effects of caffeine or combinations of caffeine and iron or vitamin E on the lipid and protein components or blood chemistry levels of the serum as well as the total homogenate, mitochondrial and microsomal fraction of the rat(Sprague-Dawley, female) liver. Chronic test were conducted to determine those effects. The chronic test was conducted by dividing rats into 5 groups according to the type of drugs and dosages administrated as follows; the control(group A), and group B was given 25mg/kg caffeine orally once daily for 30 days, group C was given 50mg/kg caffeine orally once daily for 30 days, group D was given 25mg/kg caffeine and orally ferric chloride once daily for 30 days and group E was given 25mg/kg caffeine and 25mg/kg vitamin E once daily for 30 days. The concentrations of glucose, urea nitrogen, uric acid, creatinine, total protein, albumin, A/G ratio, triglyceride, total cholesterol, HDL-cholesterol, free fatty acid, phospholipid as well as the activities of alanine aminotransferase(ALT), aspartate aminotransferase(AST) and alkaline phosphatase(ALP) were measured in the serum of each experimental groups. The concentrations of the carbonyl group and malondiaidehyde(MDA) and the patterns of the SDS-PAGE(Sodium Dodecyl Sulfate - Polyacrylamide Gel Electrophoresis) and fatty acid compositions in free fatty acids and phospholipids were analyzed to determine the oxidative damages and metabolic changes on the lipid and protein components in the serum, and total homogenate, mitochondrial and microsomal fractions of the rat liver. The results obtained from this study were summarized as follows; 1. Body weights of groups B, C, D and E were significantly decreased(p < 0.01) in comparison with that of the control in the chronic test. 2. The concentrations of serum glucose in groups B(124.5mg/dl), C(130.1mg/dl), D(122.1mg/dl), E(119.3mg/dl) were significantly higher(p < 0.01) in comparison to that of the control(101.5mg/dl). But, there were no significant differences in the concentrations of urea nitrogen, uric acid, creatinine, total protein, albumin and A/G ratio in comparison to that of the control. 3. The concentrations of total cholesterol and HDL-cholesterol in serum of groups B(69.6, 53.4mg/dl), C(73.0, 56.3mg/dl), D(68.9, 51.1mg/dl) and E(68.2, 51.3mg/dl) were significantly higher(p < 0.01) in comparison to that of the control(52.6, 38.8mg/dl). On the other hand, the concentrations of triglyceride in serum of groups B(45.0mg/dl), C(40.4mg/dl), D(33.8mg/dl) and E(47.2mg/dl) were significantly lower(p < 0.01) in comparison to that of the control(66.2mg/dl). There were no significant differences in the activities of ALT, AST and ALP in comparison to that of the control. 4. The concentrations of free fatty acid and phospholipid in serum of groups B(45.7, 154.4mg/dl), C(50.0, 167.2mg/dl), D(52.5, 148.4mg/dl) and E(41.1, 159.2mg/dl) were higher(p < 0.01) in comparison to that of the control(35.2, 125.3mg/dl). And the concentrations of the carbonyl group and malondialdehyde in serum of group D(1.82, 0.52nM/mg protein) were significantly higher(p < 0.01) in comparison to the control(1.53nM/mg protein). 5. The concentrations of carbonyl group in total homogenate, mitochondrial and microsomal fraction of group D(1.45, 0.94, 1.67nM/mg protein) were significantly higher (p < 0.01) in comparison to the control(1.16, 0.66, 1.27nM/mg protein). And the concentrations of malondialdehyde in the total homogenate, mitochondrial and microsomal fraction of group D(6.70, 6.10, 1.36nM/mg protein) were significantly higher(p < 0.01) in comparison to the control(5.17, 3.64, 0.68nM/mg protein). 6. As the analytical results of the fatty acid compositions of free fatty acid in serum, the proportions of stearic acid and arachidonic acid of groups B(16.52, 12.62%), C(17.52, 15.18%), D(19.73, 13.47%) and E(17.62, 13.28%) were significantly higher(p < 0.01) in comparison to the control(14.75, 7.88%), but the proportions of oleic acid and linoleic acid of groups B(12.97, 32.59%), C(10.88, 31.23%), D(12.37, 30.66%) and E(11.95, 32.41%) were significantly lower(p < 0.01) in comparison to the control(16.44, 35.12%). Otherwise, as the results of the fatty acid compositions of phospholipid in serum, the proportions of stearic acid and arachidonic acid of groups B(39.37, 16.39%), C(40.63, 17.83%), D(42.73, 15.39%) and E(39.16, 15.70%) were significantly higher(p < 0.01) in comparison to the control(37.74, 14.24%), but the proportions of oleic acid and linoleic acid of groups B(4.03, 14.38%), C(3.54, 12.38%), D(4.52, 11.68%) and E(4.29, 13.64%) were significantly lower(p < 0.01) in comparison to the control(5.53, 16.14%). 7. As the analytical results of the fatty acid compositions of free fatty acid in total homogenate, mitochondrial and microsomal fraction of liver, the proportions of oleic acid of groups B(7.8**, 8.73**, 6.88%) and C(6.89**, 7.75**, 6.58%) were lower(**:p < 0.01) in comparison to the control(8.67, 10.08, 7.81%), but the proportions of arachidonic acid of group C(22.62, 19.79, 23.71%) were significantly higher(p < 0.01) in comparison to the control(20.93, 18.47, 22.24%). And the proportions of palmitic acid of group D(25.95**, 26.16, 26.34**%) were significantly higher(**:p < 0.01) in comparison to the control(24.43, 25.42, 23.34%). In addition, the proportions of linoleic acid of group D(23.43, 25.02, 23.95%) were also significantly higher(p < 0.01) in comparison to the control(22.17, 23.75, 21.26%). The proportions of stearic acid of group D(19.87, 19.76**%) in mitochondrial and microsomal fraction were lower(**:p < 0.01) in comparison to the control(21.01, 24.18%), and the proportions of stearic acid of group E(16.71*, 19.65**%) in mitochondrial and microsomal fraction were significantly lower(**:p < 0.01, *:p < 0.05) in comparison to the control(21.01, 24.18%), and the proportions of linoleic acid of group E(25.04, 29.20, 26.48%) in total homogenate, mitochondria and microsome were significantly higher(p < 0.01) in comparison to the control(22.17, 23.75, 21.26%). 8. As the results of the fatty acid compositions of phospholipid in total homogenate, mitochondrial and microsomal fraction of liver, the proportions of palmitic acid of group D(17.58**, 18.78*, 18.23%**) were significantly higher(**:p < 0.01, *:p < 0.05) in comparison to the control(16.28, 17.22, 16.38%), and the proportions of stearic acid of group D(36.41, 37.23, 39.53%) were also significantly higher(p < 0.01) in comparison to the control(34.18, 34.16, 36.04%). But the proportions of oleic acid(3.41*, 3.11**, 3.12**%) and linoleic acid (18.03**, 15.79**, 14.74**%) of group D were significantly lower(**:p < 0.01, *:p < 0.05) in comparison to the control(oleic : 3.63, 3.72, 3.79%, linoleic : 20.03, 18.71, 18.48%). 9. In order to determine the oxidative damages to the protein in serum, mitochondrial and microsomal fraction of the rat liver, the patterns of the SDS-PAGE were identified, but the results of SDS-PAGE were not significantly different between the control and experimental groups.

• BMB Reports
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• v.51 no.10
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• pp.484-485
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• 2018

Receptor-interacting protein kinase-3 (RIP3 or RIPK3) is a serine-threonine kinase largely essential for necroptotic cell death; it also plays a role in some inflammatory diseases. High levels of RIP3 are likely sufficient to activate necroptotic and inflammatory pathways downstream of RIP3 in the absence of an upstream stimulus. For example, we have previously detected high levels or RIP3 in the skin of Toxic Epidermal Necrolysis patients; this correlates with increased phosphorylation of MLKL found in these patients. We have long surmised that there are molecular mechanisms to prevent anomalous activity of the RIP3 protein, and so prevent undesirable cell death and inflammatory effects when inappropriately activated. Recent discovery that Carboxyl terminus of Hsp 70-Interacting Protein (CHIP) could mediate ubiquitylation- and lysosome-dependent RIP3 degradation provides a potential protein that has this capacity. However, while screening for RIP3-binding proteins, we discovered that pellino E3 ubiquitin protein ligase 1 (PELI1) also interacts directly with RIP3 protein; further investigation in this study revealed that PELI1 also targets RIP3 for proteasome-dependent degradation. Interestingly, unlike CHIP, which targets RIP3 more generally, PELI1 preferentially targets kinase active RIP3 that has been phosphorylated on T182, subsequently leading to RIP3 degradation.