• Journal of Life Science
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• v.32 no.7
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• pp.542-549
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• 2022

Polymethoxyflavones (PMFs) are flavonoids mainly found in citrus fruits and have been reported to exhibit a wide range of bioactivities, including anti-obesity, anti-cancer, and anti-inflammatory actions. To utilize PMFs as functional materials, it is necessary to develop a simple method of obtaining PMFs from citrus tissues containing a large amount of PMFs. It has been reported that Jinkyool (C. sunki Hort ex. Tanaka) peel contained a large amount of PMFs, but there are no studies on PMFs isolated from its leaves. In this study, we established a simple procedure for obtaining the PMF-rich fraction (PRF) from the leaves of Jinkyool and investigated the effects of PRF on lipid metabolism in 3T3-L1 cells. PRF inhibited lipogenesis during the differentiation of 3T3-L1 preadipocytes. It decreased the expression of peroxisome proliferator-activated receptor gamma (PPAR𝛾) and CCAAT/enhancer binding protein alpha (CEBP𝛼), FAS, and adipocyte fatty-acid-binding protein 2 (aP2). In mature 3T3-L1 adipocytes, PRF increases the phosphorylation of protein kinase A (PKA)/hormone-sensitive lipase (HSL), which are key factors involved in lipolysis. Moreover, it increases the phosphorylation of the AMP-activated protein kinase (AMPK)/acetyl-CoA carboxylase (ACC) involved in fatty acid oxidation. These results suggest that PRF from Jinkyool leaves can be used as an anti-obesity agent with the action of inhibiting lipogenesis and promoting lipolysis and fatty acid oxidation in 3T3-L1 adipocytes.

• Journal of Animal Science and Technology
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• v.63 no.5
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• pp.1126-1141
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• 2021

Recent evidence has shown that methionine (Met) supplementation can improve milk protein synthesis under hyperthermia (which reduces milk production). To explore the mechanism by which milk protein synthesis is affected by Met supplementation under hyperthermia, mammary alveolar (MAC-T) cells were incubated at a hyperthermic temperature of 42℃ for 6 h in media with different concentrations of Met. While the control group (CON) contained a normal amino acid concentration profile (60 ㎍/mL of Met), the three treatment groups were supplemented with Met at concentrations of 10 ㎍/mL (MET70, 70 ㎍/mL of Met), 20 ㎍/mL (MET80, 80 ㎍/mL of Met), and 30 ㎍/mL (MET90,90 ㎍/mL of Met). Our results show that additional Met supplementation increases the mRNA and protein levels of BCL2 (B-cell lymphoma-2, an anti-apoptosis agent), and decreases the mRNA and protein levels of BAX (Bcl-2-associated X protein, a pro-apoptosis agent), especially at an additional supplementary concentration of 20 ㎍/mL (group Met80). Supplementation with higher concentrations of Met decreased the mRNA levels of Caspase-3 and Caspase-9, and increased protein levels of heat shock protein (HSP70). The total protein levels of the mechanistic target of rapamycin (mTOR) and the mTOR signalling pathway-related proteins, AKT, ribosomal protein S6 kinase B1 (RPS6KB1), and ribosomal protein S6 (RPS6), increased with increasing Met supplementation, and peaked at 80 ㎍/mL Met (group Met80). In addition, we also found that additional Met supplementation upregulated the gene expression of αS1-casein (CSN1S1), β-casein (CSN2), and the amino acid transporter genes SLC38A2, SLC38A3 which are known to be mTOR targets. Additional Met supplementation, however, had no effect on the gene expression of κ-casein (CSN3) and solute carrier family 34 member 2 (SLC34A2). Our results suggest that additional Met supplementation with 20 ㎍/mL may promote the synthesis of milk proteins in bovine mammary epithelial cells under hyperthermia by inhibiting apoptosis, activating the AKT-mTOR-RPS6KB1 signalling pathway, and regulating the entry of amino acids into these cells.

• Journal of Applied Biological Chemistry
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• v.66
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• pp.186-196
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• 2023

Dyglomera^® is an aqueous ethanol extract derived from the fruit and pods of Dichrostachys glomerata. A previous study has revealed that Dyglomera regulates adipogenesis and lipolysis by modulating AMP-activated protein kinase (AMPK) phosphorylation and increased expression levels of lipolysis-related proteins in white adipose tissue of high fat diet-induced mice and 3T3-L1 adipocyte cells. To further investigate mechanisms of Dyglomera, additional studies were performed using 3T3-L1 cells. Results revealed that Dyglomera downregulated adipogenesis by inhibiting the protein kinase B/mammalian target of rapamycin signaling pathway and reconfirmed that it downregulated gene expression levels of proliferator-activated receptor (PPAR)-γ, CCAAT enhancer binding protein α, sterol-regulation element-binding protein-1c. Dyglomera also reduced adipokines such as tumor necrosis factor alpha, interleukin-1β, and interleukin 6 by regulating leptin expression. Moreover, Dyglomera promoted beige-and-brown adipocyte-related phenotypes and regulated metabolism by increasing mitochondrial number and expression levels of genes such as T-box protein 1, transmembrane protein 26, PR domain 16, and cluster of differentiation 40 as well as thermogenic factors such as uncoupling protein 1, proliferator-activated receptor-gamma co-activator-1α, Sirtuin 1, and PPARα through AMPK activation. Thus, Dyglomera not only can inhibit adipogenesis, but also can promote lipolysis and thermogenesis and regulate metabolism by affecting adipokine secretion from 3T3-L1 adipocytes.

• Animal cells and systems
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• v.12 no.3
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• pp.143-148
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• 2008

Heterogeneous nuclear ribonucleoprotein E1(hnRNP E1) is one of the primary pre-mRNA binding proteins in human cells. It consists of 356 amino acid residues and harbors three hnRNP K homology(KH) domains that mediate RNA-binding. The hnRNP E1 protein was shown to play important roles in mRNA stabilization and translational control. In order to enhance our understanding of the cellular functions of hnRNP E1, we searched for interacting proteins through a yeast two-hybrid screening while using HeLa cDNA library as target. One of the cDNA clones was found to be human ribosomal protein L18a cDNA(GenBank accession number BC071920). We demonstrated in this study that human ribosomal protein L18a, a constituent of ribosomal protein large subunit, interacts specifically with hnRNP E1 in the yeast two-hybrid system. Such an interaction was observed for the first time in this study, and was also verified by biochemical assay.

• Journal of Food Hygiene and Safety
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• v.18 no.1
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• pp.25-29
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• 2003

The p60 protein of Listeria spp. is a Listeria-Genus-specific, major extra-cellular protein, which is used as an indicator protein for the detection of these bacteria from contaminated foods. In this study, p60 protein were recombinantly produced in E. coli and were purified using amylose resin based column chromatography. Purified recombinant-p6O was used to generate monoclonal antibody against native p60. Antibody from hybridoma cell line, 1H4, specificically reacted with native p60 protein isolated from pathogenic Listeria spp. such as L. monocytogenes, L. ivanovii, L. welshimeri II, but did not or relatively weakly reacted with non-pathogenic Listeia species, L. innocua or other bacterial proteins. Antibody from 1H4 was produced using ascites fluid method and it may be useful to develop the Listeria-detection kits based on immunological method.

• Journal of Life Science
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• v.30 no.1
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• pp.10-17
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• 2020

Kinesin-1 is microtubule-dependent plus-end direct molecular motor protein essential for intracellular transport. It is a member of the kinesin superfamily proteins (KIFs) which transport cargo, including organelles, vesicles, neurotransmitter receptors, cell-signaling molecules, and protein complexes through interaction between its light chain subunit and the cargo. Kinesin light chain 1 (KLC1) is a non-motor subunit that associates with the kinesin heavy chain (KHC). Although KLC1 interacts with many different adaptor proteins and scaffolding proteins, its binding proteins have not yet been fully identified. We used the yeast two-hybrid assay to identify proteins that interact with the tetratricopeptide repeat (TPR) domain of KLC1, and found an interaction between KLC1 and EH domain-binding protein 1 like 1 (EHBP1L1). EHBP1L1 bound to the region containing all six TPR repeats of KLC1 and did not interact with KIF5B (a motor protein of kinesin 1) or KIF3A (a motor protein of kinesin 2) in the yeast two-hybrid assay. The carboxyl-terminus of the coiled-coil domain of EHBP1L1 is essential for interaction with KLC1. However, another EHBP1L1 isoform, EHBP1, did not interact with KLC1 in the yeast two-hybrid assay. KLC1 interacted with GST-EHBP1L1 and its coiled-coil domain but not with GST only. When co-expressed in HEK-293T cells, EHBP1L1 co-localized with KLC1 and co-immunoprecipitated with KLC1 and KIF5B but not KIF3A. These results suggest that kinesin 1 motor protein may transport EHBP1L1-associated cargo in cells.

• Journal of Yeungnam Medical Science
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• v.14 no.1
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• pp.67-76
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• 1997

The occurrence of multidrug resistance (MDR) is one of the main obstacles in the successful chemotherapeutic treatment of cancer. In this study The gene expressions of multidrug resistance-associated protein (MRP), c-myc and c-fos were investigated in L1210 cells. Adriamycin- or vincristine-resistant L1210 cells, L1210AdR or L1210VcR, respectively, has been identified to overexpression of mdr1 gene. The expression leve of MRP gene in L1210AdR and L1210Cis was more decreased than that in L1210 cells. The c-myc and c-fos genes were expressed both in L1210 and resistant sublines. In L1210AdR, the expressions level of c-myc and c-fos genes were decreased than in L1210. However, in L1210VcR and L1210Cis, c-myc and c-fosgene expressionwere rather increased than L1210. These results suggested that MRP does not contribute in resistance of drug-resistant L1210 cells and there is no relations between MRP and mdr1 gene expression. The expression of c-myc and c-fos gene may be changed during transformation of L1210 to drug-resistant sublines.

• Korean Journal of Food Science and Technology
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• v.12 no.4
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• pp.263-271
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• 1980

Detoxified and deallergenized castor bean protein isolate was prepared from defatted castor bean pomace for use in animal feedstuffs and human foods. Succinylation and acetylation of the ${\varepsilon}-amino$ groups of the protein improved markedly the water solubility of the protein at $pH\;7{\sim}8$. The results of the amino acid analysis of the protein isolate revealed that the sulfur-containing amino acids and L-lysine were limiting amino acids and that succinylation and acetylation caused some little loss of the amino acid content. The L-methionine enriched plastein was synthesized from the protein isolate or the acylated protein isolates and DL-methionine ethyl ester by one step process with papain. By this method the extent of incorporation of L-methionine was about 50%. Pepsin hydrolyzed both unmodified and modified protein isolates at the same rate (about 92%). Tryptic hydrolysis, however, was less for the succinylated protein isolates (about 42%) and less for the acetylated protein isolates (about 26%). The protein efficiency ratio of L-methionine enriched protein isolate (about 2.5 weight %) was 90% that of reference casein. The protein efficiency ratio values of succinylated (88%) and acetylated (84%) protein isolate were 55 and 69% of reference casein, respectively.

• Journal of Physiology & Pathology in Korean Medicine
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• v.30 no.6
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• pp.432-438
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• 2016

This study was peformed to investigate the mechanism of ethanol extract of Eclipta Prostrata (L.) L. (EEP) induced melanogenesis. EEP enhanced tyrosinase activity and melanin contents of B16F10 cells. Moreover, EEP increased the protein expression of tyrosinase and tyrosinase-related protein 1 (TRP-1). But EEP did not increase the protein expression of tyrosinase-related protein 2 (TRP-2). These results suggest that melanogenesis-promoting effect of EEP was involved in regulation of tyrosinaase and TRP-1 protein, and EEP may be a potent pigmentation darkening agent in hypopigmentation condition.

• Korean Journal of Plant Tissue Culture
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• v.25 no.3
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• pp.177-181
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• 1998

This study was carried out to investigate activity difference in the superoxide dismutase (SOD) and peroxidase (POD) of tomato callus transformed with Agrobacterium containing the GUS gene. Than those of other two tomato cultivars, the hypocotyl explant of JA101 was shown to have higher POD and SOD specific activity of 23 unit/mg protein and 2,156 unit/mg protein, respectively. Relatively high frequency of callus formation was obtained from the hypocotyl explant on MS medium containing 1 mg/L 2,4-D for 30 days and its POD(47 unit/mg protein) and SOD (95,786 unit/mg protein) specific activities were higher than other 2,4-D concentration. The hypocotyl explant and callus cocultivated with Agrobacterium for 72 hours were transferred to MS medium supplemented with 1 mg/L 2,4-D, 30 mg/L kanamycin, 30 g/L sucrose and 4 g/L Gelrite. The hypocotyl explants transferred to the medium formed callus with 45.5% effeciency after 8 weeks. The transformation efficiency confirmed by GUS assay was 21.6%. POD specific activity of the transformed callus (54 unit/mg protein) were somewhat lower than the non-transformed callus (64 unit/mgg protein) and SOD specific activity of the transformed callus (30,300 unit/mg protein) were also lower than the non-transformed callus (37,077 unit/mg protein). However there was no significant difference in POD and SOD isozyme patterns between the transformed and the non-transformed calluses. From these results, it revealed that there was no difference of antioxidant enzyme activities between the transformed callus and the non-transformed callus in tomato.