• Journal of Microbiology and Biotechnology
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• 제33권12호
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• pp.1563-1575
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• 2023

Acyl-coenzyme A (CoA):diacylglycerol acyltransferase 2 (DGAT2) catalyzes the last stage of triacylglycerol (TAG) synthesis, a process that forms ester bonds with diacylglycerols (DAG) and fatty acyl-CoA substrates. The enzymatic role of Dgat2 has been studied in various biological species. Still, the full description of how Dgat2 channels fatty acids in skeletal myocytes and the consequence thereof in glucose uptake have yet to be well established. Therefore, this study explored the mediating role of Dgat2 in glucose uptake and fatty acid partitioning under short interfering ribonucleic acid (siRNA)-mediated Dgat2 knockdown conditions. Cells transfected with Dgat2 siRNA downregulated glucose transporter type 4 (Glut4) messenger RNA (mRNA) expression and decreased the cellular uptake of [1-¹⁴C]-labeled 2-deoxyglucose up to 24.3% (p < 0.05). Suppression of Dgat2 deteriorated insulin-induced Akt phosphorylation. Dgat2 siRNA reduced [1-¹⁴C]-labeled oleic acid incorporation into TAG, but increased the level of [1-¹⁴C]-labeled free fatty acids at 3 h after initial fatty acid loading. In an experiment of chasing radioisotope-labeled fatty acids, Dgat2 suppression augmented the level of cellular free fatty acids. It decreased the level of re-esterification of free fatty acids to TAG by 67.6% during the chase period, and the remaining pulses of phospholipids and cholesteryl esters were decreased by 34.5% and 61%, respectively. Incorporating labeled fatty acids into beta-oxidation products increased in Dgat2 siRNA transfected cells without gene expression involving fatty acid oxidation. These results indicate that Dgat2 has regulatory function in glucose uptake, possibly through the reaction of TAG with endogenously released or recycled fatty acids.

• Journal of Plant Biotechnology
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• 제39권4호
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• pp.242-252
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• 2012

Seed storage oils are essential resources for not only human and animal diets but also industrial applications. The primary goal of this study was to increase seed oil content through comparative analysis of two seed-specific promoters, AtFAE1 from Arabidopsis Fatty Acid Elongase 1 gene and BnNapin from Brassica napus seed storage protein gene. AtWRI1 and AtDGAT1 genes encoding an AP2-type transcription factor and a Diacylglycerol Acyltransferase 1 enzyme, respectively, were expressed under the control of AtFAE1 and BnNapin promoters in Arabidopsis. The total seed oil content in all transgenic plants was increased by 8-11% compared with wild-type seeds. The increased level of oil content in AtWRI1 and AtDGAT1 transgenic lines under the control of both promoters was similar, although the activity of the BnNapin promoter is much stronger than that of AtFAE1 promoter in the mature stage of developing seeds where storage oil biosynthesis occurs at a maximum rate. This result demonstrates that the AtFAE1 promoter as well as the BnNapin promoter can be used to increase the seed oil content in transgenic plants.

• Asian-Australasian Journal of Animal Sciences
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• 제22권7호
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• pp.943-954
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• 2009

Diacylglycerol acyltransferase (DGAT) is a key enzyme that catalyzes the final and rate-limiting step of triglyceride synthesis. Both DGAT1 and DGAT2 genes code proteins with DGAT activity. Studies have shown DGAT1 polymorphisms associate with intramuscular fat deposition in beef cattle, but fewer associations between DGAT2 and beef cattle economic traits have been reported. The objective of this study was to investigate single nucleotide polymorphism (SNP) in intron3 of bovine DGAT2 and evaluate the associations of that with carcass, meat quality, and fat yield traits. Test animals were 157 commercial feedlot steers belonging to 3 Chinese native breeds (22 for Luxi, 24 for Jinnan, and 23 for Qinchuan), 3 cross populations (20 for Charolais${\times}$Fuzhou, 18 for Limousin ${\times}$Luxi, and 17 for Simmental${\times}$Jinan) and 1 Taurus pure breed population (16 Angus steers). In the current study, 15 SNP were discovered in intron3 and exon4 of DGAT2 at positions 65, 128, 178, 210, 241, 255, 270, 312, 328, 334, 365, 366, 371, 415, and 437 (named as their positions in PCR amplified fragments). Only 7 of them (128, 178, 241, 270, 312, 328, and 371) were analyzed, because SNP in three groups (65-128-255, 178-210-365 and 241-334-366) were in complete linkage disequilibrium within the group, and SNP 415 was a deletion and 437 was a null mutation. Frequencies for rare alleles in the 3 native breed populations were higher than in the 3 cross populations for 178 (p = 0.04), 270 (p = 0.001), 312 (p = 0.03) and 371 (p = 0.002). A general linear model was used to evaluate the associations between either SNP genotypes or allele substitutions and the measured traits. Results showed that SNP 270 had a significant association with the fat yield associated with kidney, pelvic cavity, heart, intestine, and stomach (KPHISY). Animals with genotype CC and CT for 270 had less (CC: -7.71${\pm}$3.3 kg and CT: -5.34${\pm}$2.5 kg) KPHISY than animals with genotype TT (p = 0.02). Allele C for 270 was associated with an increase of -4.26${\pm}$1.52 kg KPHISY (p = 0.006) and $-0.92{\pm}0.45%$ of retail cuts weight percentage (NMP, Retail cuts weight/slaughter body weight) (p = 0.045); allele G for 312 was associated with an increase of -5.45${\pm}$2.41 kg KPHISY (p = 0.026). An initial conclusion was that associations do exist between DGAT2 gene and carcass fat traits. Because of the small sample size of this study, it is proposed that further effort is required to validate these findings in larger populations.

• Asian-Australasian Journal of Animal Sciences
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• 제20권6호
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• pp.817-820
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• 2007

The effects of diacylglycerol O-acyltransferase (DGAT1) candidate gene polymorphism on the economic traits of Hanwoo were studied. Through sequencing analysis, two polymorphism sites at K232A and T11993C were established and were analyzed by PCR-RFLP. The PCR-RFLP analysis for K232A showed that the frequencies of alleles K and A were 0.75 and 0.25, respectively, and the frequencies of genotypes for K/K, K/A and A/A were estimated as 0.509, 0.491 and 0, respectively. In the PCR-RFLP analysis for T11993C, we found allele frequencies of 0.773 and 0.227 for T and A, respectively, and 0.546, 0.454 and 0 for the T/T, T/C and C/C genotype frequencies, respectively. No significant effects on economic traits in Hanwoo were found in the separate analysis of K232A and T11993C polymorphisms, but the interaction between K232A and T11993C showed a significant effect (p<0.005) on marbling score. The DGAT1 candidate gene was found to have a significant effect not only on milk yield and component traits but also on the metabolism of intramuscular fat.

• Food Science and Biotechnology
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• 제18권1호
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• pp.95-102
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• 2009

The aerial parts of garland (Chrysanthemum coronarium L.) were extracted in 80% aqueous methanol (MeOH) and the concentrated extract was then partitioned using ethyl acetate (EtOAc), n-butanol (n-BuOH), and $H_2O$, successively. EtOAc and n-BuOH fractions resulted in 4 glycerides with the application of octadecyl silica gel and silica gel column chromatography. The chemical structures of the glycerides were determined using several spectroscopic methods, including nuclear magnetic resonance (NMR) and mass spectrometry (MS) as (2S)-1-O-palmitoyl-sn-glycerol (1), (2S)-1-O-oleoyl-2-O-oleoyl- 3-O-$\beta$-D-galactopyranosyl-sn-glycerol (2), (2S)-1-O-palmitoyl-2-O-linoleoyl-3-O-phosphorouscholine-sn-glycerol (3), and (2S)-1-O-linolenoyl-2-O-palmitoyl-3-O-[$\alpha$-D-galactopyrasyl-($1{\rightarrow}6$)-$\beta$-D-galactopyranosyl]-sn-glycerol (4). The free fatty acids of these glycerides were determined with gas chromatography (GC)-MS analysis following alkaline hydrolysis and methylation. These glycerides demonstrated an inhibitory effect on acyl-CoA: cholesterol acyltransferase (ACAT, compound 1: $45.6{\pm}0.2%$ at $100{\mu}g/mL$), diacylglycerol acyltransferase (DGAT, compound 1: $59.1{\pm}0.1%$ at $25{\mu}g/mL$), farnesyl protein transferase (FPTase, compound 2: $98.0{\pm}0.1%$; compound 3: $55.2{\pm}0.1%$ at $100{\mu}g/mL$), and $\beta$-secretase ($IC_{50}$, compound 4: $2.6{\mu}g/mL$) activity. This paper is the first report on the isolation of these glycerides from garland and their inhibitory activity on ACAT, DGAT, FPTase, and $\beta$-secretase.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2017년도 9th Asian Crop Science Association conference
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• pp.191-191
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• 2017

Hydroxy fatty acid (HFA) is an important industrial resource that known to be extracted from seeds of Castor or Lesquerella. However, mass production of HFA from those crops are difficult because of their behavior or life cycle. In this study, we applied HFA synthesis related gene FAH12, RcPDAT1, RcLPCAT, RcDGAT2, and RcPDCT on bioenergy crop Camelina sativa. Furthermore, we determined NaCl or cold stress tolerance changes of transgenic Camelina. RcFAH12, RcPDAT1, RcLPCAT, RcDGAT2, and RcPDCT genes were cloned into multigene expression vector which is engineered with seed specific promoter of FAE1 or Napin. Combination of HFA genes multi-expression vector constructs were divided into Set3 (RcFAH12, RcPDAT1-2, RcLPCAT), Set4 (RcFAH12, RcDGAT2, RCPDAT1-2, RcLPCAT), and Set5 (RcFAH12, RcDGAT2, RCPDAT1-2, RcLPCAT, RcPDCT). Transgenic HFA synthesis Camelina plants were generated using agrobacterium-mediated vacuum infiltration system. Results of fatty acid composition of T1 transgenic Camelina seeds analyzed by GC-MS showed 9.5, 9.0, and 13.6 % of HFA contents in Set3#6, Set4#8, and Set5#10, respectively. Therefore, seeds of T2 generation were harvest from Set5#10 which is shown highest HFA contents, and, 17.7, 8.1 and 10.5 % of HFA contents were determined in Set5#10-5, Set5#10-8, and Set#10-10, respectively. However, 7.7% of C18:2 and 22.3 % of C18:3 among unsaturated fatty acids were decreased in Set5#10-5 than WT. Meanwhile, we confirmed abiotic stress responses in T2 transgenic Camelina Set5#10-5 and Set5#10-10 under 0, 100, 150, and 200 mM NaCl or 25, 15, and $10^{\circ}C$ temperature for 5 weeks. Both Set5#10-5 and Set5#10-10 showed lower growth in height than WT in control and NaCl condition. Growth of leaf length and width were similar in WT and Set5#10-10 but lower in Set5#10-5 under NaCl stress. Number of opened flowers showed that both transgenic Camelina were lower than WT under normal condition. But, WT and Set5#10-10 showed similar opened flower number in 100 and 200 mM NaCl. In cold stress, 15 and $10^{\circ}C$ treatment for 5 weeks did not showed significant changes in between WT and both transgenic lines even they showed different growth rate in control condition. Taken together, growth and development are delayed by expression of exogenous HFA related genes in transgenic lines but relative abiotic stress sensitivity is similar with WT. In conclusion, reduced C18:2 or C18:3 fatty acid composition of seed by HFA synthesis is resulted from lack of resource supplement for development at seedling stage but it is not affect NaCl and cold stress tolerance.

• Journal of Plant Biotechnology
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• 제41권3호
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• pp.107-115
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• 2014

식물지방은 주로 종자에서 생산되는데 인류에게 필수 지방산을 공급하는 식품 뿐 아니라 바이오디젤 등 산업원료로 그 이용가치가 크다. 식물지방의 수요 증가에 따른 식물지방의 생산증대가 필요하다. 식물지방을 종자 이외의 바이오매스가 큰 식물의 잎에서 생산한다면 식물지방 생산 증진이 가능할 것이다. 잎은 지방을 생산하는 기관이 아니며 주로 광합성을 통해 탄소를 고정하여 다른 기관으로 탄소를 공급하는 기능을 하고 있어 지방을 생산 축적하는 기관으로 전환하는 데는 많은 고려가 필요하다. 그럼에도 불구하고 최근 지방합성 조절인자인 WRI 유전자, 지방을 생성하는 acyltransferase인 DGAT 유전자의 발현에 의해 잎에서 지방을 합성할 수 있었다. 또한 지방의 분해를 안정화하는 올레오신 단백질의 추가 도입으로 잎에서 건조중량당 15%의 중성지방 생산을 보여 잎에서 지방생산 가능성을 보여주었다(Vanhercke et al. 2014). 앞으로 바이오매스에서 지방을 생산하는 연구가 활발할 것으로 예측되며 이 기술을 식용작물이 아닌 비식용이며 바이오매스가 큰 거대억새 등에 도입하여 농지로 적합하지 않은 열악한 토지 및 간척지 등에 재배하여 실용화한다면 미래 지속 생산 가능 친환경 바이오 원료 생산 자원으로 사용 가능하리라 사료된다.