• Title/Summary/Keyword: LRP4

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Analysis of quaternary structure of leucine-responsive regulatory protein (Lrp) by crosslink experiments (교차결합 실험을 통한 루신 대응 조절 단백질의 4차 구조 분석)

  • Lee, Euiho;Pokoo, Robert;Nguyen, Loi Thuan;Lee, Chan Yong
    • Korean Journal of Microbiology
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    • v.53 no.4
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    • pp.297-303
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    • 2017
  • Leucine-responsive regulatory protein (LRP) is a regulatory protein of molecular weight 18.8 kDa and is widely known to regulate many metabolic and functional activities of operons in Escherichia coli. The gene for Lrp from Escherichia coli in pQE system of 6 ${\times}$ His-tagging was expressed and $^3H$-labeled protein, as well as the wild type Lrp, was purified. The crosslink experiments were performed to analyze the quaternary structure of Lrp at high of $5{\mu}M$ and at low concentrations below $0.3{\mu}M$ with cross linkers, such as glutaraldehyde, 1, 2, 3, 4-diepoxy-butane (DEB), and ethylene glycol bis (succinimidyl succinate) (EGS). In the experiments, we found that the Lrp protein can be formed higher conformation states of tetramer, hexamer, octamer, as well as dimeric state when incubated with the above cross linkers.

Fluorescence Characteristics of a Tryptophan Mutant of Leucine-responsive Regulatory Protein (Lrp) (트립토판 돌연변이 루신-반응 조절 단백질의 형광 특성)

  • Pokoo, Robert;Lee, Eui Ho;Lee, Chan Yong
    • Korean Journal of Microbiology
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    • v.50 no.4
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    • pp.275-280
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    • 2014
  • Leucine-responsive Regulatory Protein (Lrp) from Escherichia coli is an 18.8 kDa protein composed of 164 amino acids. Wild type Lrp (Lrp Wt) does not possess any tryptophan amino acid which has strong intrinsic fluorescence, whereas the mutant Lrp R145W contains a single tryptophan at the position 145 in the leucine-responsive domain. To investigate the fluorescence character, the Lrp R145W and Lrp Wt proteins were purified. The fluorescence intensity of Lrp R145W is much higher than that of wild type protein, and the intensity of Lrp R145W was decreased by binding to its specific DNA designed from ilvIH operon and to L-leucine. In addition, the tryptophan fluorescence intensity of Lrp R145W was strongly quenched by addition of acrylamide even in the least amount of concentration as well as by urea. The data obtained from this study may give valuable information on the three dimensional structure of Lrp R145W.

The novel gene LRP15 is regulated by DNA methylation and confers increased efficiency of DNA repair of ultraviolet-induced DNA damage

  • Xu, Zhou-Min;Gao, Wei-Ran;Mei, Qi;Chen, Jian;Lu, Jing
    • BMB Reports
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    • v.41 no.3
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    • pp.230-235
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    • 2008
  • LRP15 is a novel gene cloned from lymphocytic cells, and its function is still unknown. Bioinformatic data showed that LRP15 might be regulated by DNA methylation and had an important role in DNA repair. In this study, we investigate whether the expression of LRP15 is regulated by DNA methylation, and whether overexpression of LRP15 increases efficiency of DNA repair of UV-induced DNA damage in HeLa cells. The results showed (1) the promoter of LRP15 was hypermethylated in HeLa cells, resulting a silence of its expression. Gene expression was restored by a demethylating agent, 5-aza-2'-deoxycytidine, but not by a histone deacetylase inhibitor, trichostatin A; (2) overexpression of LRP15 inhibited HeLa cell proliferation, and the numbers of cells in the G2/M phase of the cell cycle in cells transfected with LRP15 increased about 10% compared with controls; (3) cyclin B1 level was much lower in cells overexpressing LRP15 than in control cells; and (4) after exposure to UV radiation, the LRP15-positive cells showed shorter comet tails compared with the LRP15-negative cells. From these results we conclude that the expression of LRP15 is controlled by methylation in its promoter in HeLa cells, and LRP15 confers resistance to UV damage and accelerates the DNA repair rate.

Biochemical Characteristics of Lrp (Leucine-responsive Regulatory Protein) as a Global Regulator in Escherichia coli (대장균의 Global 조절 단백질인 Lrp (Leucine-responsive Regulatory Protein)의 생화학적 특성)

  • Lee, Chan-Yong;Kim, So-Young;Kim, Ryu-Ryun
    • Korean Journal of Microbiology
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    • v.42 no.4
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    • pp.239-245
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    • 2006
  • Leucine-responsive Regulatory Protein (Lrp) is a global regulator involved in modulating a variety of metabolic functions, including the catabolism and anabolism of amino acids as well as pili synthesis. In addition, there is growing evidences that Lrp may play an important role when cells make transition between rich and lean nutritional conditions. In this review, the biochemical characteristics of Lrp are described to provide a good example that shows how bacteria adapt to nutrient limitation and environmental stress.

High Expression of Lung Resistance Protein mRNA at Diagnosis Predicts Poor Early Response to Induction Chemotherapy in Childhood Acute Lymphoblastic Leukemia

  • Bhatia, Prateek;Masih, Shet;Varma, Neelam;Bansal, Deepak;Trehan, Amita
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.15
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    • pp.6663-6668
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    • 2015
  • Background: Treatment failure in leukemia is due to either pharmacokinetic resistance or cell resistance to drugs. Materials and Methods: Gene expression of multiple drug resistance protein (MDR-1), multidrug resistance-related protein (MRP) and low resistance protein (LRP) was assessed in 45 pediatric ALL cases and 7 healthy controls by real time PCR. The expression was scored as negative, weak, moderate and strong. Results: The male female ratio of cases was 2.75:1 and the mean age was 5.2 years. Some 26/45 (58%) were in standard risk, 17/45(38%) intermediate and 2/45 (4%) in high risk categorie, 42/45 (93%) being B-ALL and recurrent translocations being noted in 5/45 (11.0%). Rapid early response (RER) at day 14 was seen in 37/45 (82.3%) and slow early response (SER) in 8/45 (17.7%) cases. Positive expression of MDR-1, LRP and MRP was noted in 14/45 (31%), 15/45 (33%) and 27/45 (60%) cases and strong expression in 3/14 (21%), 11/27 (40.7%) and 8/15 (53.3%) cases respectively. Dual or more gene positivity was noted in 17/45 (38%) cases. 46.5 % (7/15) of LRP positive cases at day 14 were in RER as compared to 100% (30/30) of LRP negative cases (p<0.05). All 8 (100%) LRP positive cases in SER had strong LRP expression (p=<0.05). Moreover, only 53.3% of LRP positive cases were in haematological remission at day 30 as compared to 100% of LRP negative cases (p=<0.05). Conclusions: Our study indicated that increased LRP expression at diagnosis in pediatric ALL predicts poor response to early treatment and hence can be used as a prognostic marker. However, larger prospective studies with longer follow up are needed, to understand the clinical relevance of drug resistance proteins.

Physicochemical and Sensory Characteristics of Tofu Prepared with Lotus Root Powder (연근 분말 첨가량에 따른 두부의 이화학적 및 관능적 특성)

  • Park, Bock-Hee;Kim, Sung-Doo;Jeon, Eun-Raye;Cho, Hee-Sook
    • Journal of the East Asian Society of Dietary Life
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    • v.20 no.4
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    • pp.516-523
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    • 2010
  • This study was conducted to investigate the physicochemical and sensory characteristics of tofu prepared with the addition of lotus root powder (LRP). The moisture, crude ash, carbohydrate, crude protein, and crude lipid contents of the lotus root powder were 8.29%, 4.73%, 30.66%, 47.84%, and 8.48%, respectively. The yield rate of the tofu did not differ significantly according to the level of added LRP; however, there was a significant decrease in pH and a significant increase in acidity. The L and b values of the tofu decreased as the amount of LRP in the formulation increased, whereas the a value increased. Furthermore, hardness and cohesiveness increased significantly as the level of LRP increased. In sensory evaluation, LRP tofu had low scores in air cell size and a beany smell, but high scores in hardness. In terms of overall acceptability, the preferred tofu samples were the control and that containing 0.3% lotus root powder.

Reduced Port Surgery for Prostate Cancer is Feasible: Comparative Study of 2-port Laparoendoscopic and Conventional 5-port Laparoscopic Radical Prostatectomy

  • Akita, Hidetoshi;Nakane, Akihiro;Ando, Ryosuke;Yamada, Kenji;Kobayashi, Takahiro;Okamura, Takehiko;Kohri, Kejiro
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.11
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    • pp.6311-6314
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    • 2013
  • Background: While 5-port laparoendoscopic radical prostatectomy is standard practice, efforts have been focused in developing a single port surgery for cosmetic reasons. However, this is still in the pioneering stage considering the challenging nature of the surgical procedures. We have therefore focused on reduced port surgery, using only 2-ports. In this study, we compared 2-port laparoendoscopic radical prostatectomy (2-port RP) and conventional 5-port laparoscopic radical prostatectomy (LRP) for clinically localized prostate carcinoma and evaluated the potential advantages of each. Materials and Methods: From January 2010 to December 2010, all 23 patients with clinically localized prostate cancer underwent LRP. Starting November, 2010, when we introduced the reduced port approach, we performed this procedure for 22 consecutive patients diagnosed with early-stage prostate cancer (cT1c, cT2N0). The patients were matched 1:1 to 2-port RP or LRP for age, preoperative serum PSA level, clinical stage, biopsy and pathological Gleason grade, surgical margin status, pad-free rates and post-operative pain. Results: There was a significant difference in operative time between the 2-port RP and LRP groups ($286.5{\pm}63.3$ and $351.8{\pm}72.4$ min: p=0.0019, without any variation in blood loss (including urine) ($945.1{\pm}479.6$ vs $1271.1{\pm}871.8ml$: p=0.13). The Foley catheter indwelling period was shorter in the 2 port RP group, but without significance ($5.6{\pm}1.8$ vs $8.0{\pm}5.6$ days: p=0.057) and the total perioperative complication rates for 2 port RP and LRP were comparable at 4.5% and 8.7% (p=0.58). There was an improvement in pad-free rates up to 6 months follow-up (p=0.090), and significantly improvement at 1 year (p=0.040). PSA recurrence was 1 (4.5%) in 2-port RP and 2 (8.7%) in LRP. Continuous epidural anesthesia was used in most of LRP patients (95.7%) and in early 2-port RP patients (40.9%). In these patients, average total amount of Diclofenac sodium was 27.8mg/patient in 2-port RP and 50.0mg/patient in LRP. Conclusions: Thus the reduced port approach is as efficacious as LRP in terms of many outcome measures, with significant cosmetic advantages and reduction in post surgical pain. This method can be readily performed safely and therefore can be recommended as a standard laparoscopic surgery for prostate cancer in the future.

Genetic Polymorphisms of ARMC4, LRP4 and BCL2 Genes are Associated with Blood Pressure Traits and Hypertension in Korean Population

  • Park, Hye-Jeong;Jeon, Tae-Eun;Kim, Yong-Seob;Jin, Hyun-Soek;Park, Sangjung
    • Biomedical Science Letters
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    • v.26 no.1
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    • pp.28-36
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    • 2020
  • High blood pressure (HTN) is a condition in which blood pressure is kept higher than normal. Blood pressure trait measures systolic blood pressure (SBP) which is the highest pressure and diastolic blood pressure (DBP) which is the lowest blood pressure. Pulse pressure (PP) is the difference between systolic and diastolic blood pressure. Hypertension is known as a disease caused by the interaction of the environment and genetic factors. To date, studies have been conducted to find genes associated with hypertension. Genome-Wide Association Study (GWAS) analysis using European data from the UK Biobank reported new 535 loci were associated with blood pressure trait. Among them, 12 genes have been reported to have a significant correlation with SBP, DBP and PP. In the study, 12 genes polymorphisms were extracted based on KARE (Korean association resource) and then we performed linear regression of blood pressure trait. As a result, 6 SNPs of the 3 genes (rs12355413 and rs11006736 of ARMC4, rs2290883, rs2290884 and rs11039014 of LRP4, rs7234941 of BCL2) showed statistically significant correlation (P<0.05) with blood pressure trait. Of the 3 genes, 6 SNPs in 2 genes (rs9651357, rs12355413, rs11006736, rs1889522 of ARMC4 and rs4987774, rs7234941 of BCL2) showed significant correlation with hypertension. These results suggest that genetic polymorphisms of ARMC4, LRP4 and BCL2 genes are associated with blood pressure traits and hypertension in Korean population. Moreover, we expected to help understand the pathogenesis of hypertension.

Quality of Soybean Paste (Doenjang) Prepared with Lotus Root Powder (연근 분말을 첨가한 된장의 품질 특성)

  • Park, In-Bae;Park, Jeong-Wook;Kim, Jeong-Mok;Jung, Soon-Teck;Kang, Seong-Gook
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.34 no.4
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    • pp.519-523
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    • 2005
  • Soybean paste (Doenjang) was prepared by adding Lotus root powder (LRP) at $5\~15\%$ (w/w) to improve quality of the Doenjang and to give some functional properties. Moisture content was ranged about $50.05\~54.04\%$ and amino nitrogen content was $635\~648\;mg\%$ following the LRP contents. Crude protein amounts were $11.55\~12.56\%$ that was no difference between test samples. Carbohydrates contents increased $1.5\~2$ times in the test samples than the control depending on the LRP contents. However, contents of crude lipid $(6.99\~8.55\%)$ and ash $(13.99\~15.17\%)$ were decreased as increased the amounts of LRP. The pH of the product was decreased until 45 days during aging period and then slightly increased without significantly differences among test samples. The values of acidity were $1.85\~2.18\%$ at the early stage of aging but slightly increased with further aging. The total phenolic content in the Doenjang adding $15\%$ LRP was $461.8\;mg\%$ which is higher than $368.6\;mg\%$ in the control. Doenjang prepared with LRP showed an anti-browning effect of the product itself.

Apolipoprotein E in Synaptic Plasticity and Alzheimer's Disease: Potential Cellular and Molecular Mechanisms

  • Kim, Jaekwang;Yoon, Hyejin;Basak, Jacob;Kim, Jungsu
    • Molecules and Cells
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    • v.37 no.11
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    • pp.767-776
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    • 2014
  • Alzheimer's disease (AD) is clinically characterized with progressive memory loss and cognitive decline. Synaptic dysfunction is an early pathological feature that occurs prior to neurodegeneration and memory dysfunction. Mounting evidence suggests that aggregation of amyloid-${\alpha}$ ($A{\alpha}$) and hyperphosphorylated tau leads to synaptic deficits and neurodegeneration, thereby to memory loss. Among the established genetic risk factors for AD, the ${\varepsilon}4$ allele of apolipoprotein E (APOE) is the strongest genetic risk factor. We and others previously demonstrated that apoE regulates $A{\alpha}$ aggregation and clearance in an isoform-dependent manner. While the effect of apoE on $A{\alpha}$ may explain how apoE isoforms differentially affect AD pathogenesis, there are also other underexplored pathogenic mechanisms. They include differential effects of apoE on cerebral energy metabolism, neuroinflammation, neurovascular function, neurogenesis, and synaptic plasticity. ApoE is a major carrier of cholesterols that are required for neuronal activity and injury repair in the brain. Although there are a few conflicting findings and the underlying mechanism is still unclear, several lines of studies demonstrated that apoE4 leads to synaptic deficits and impairment in long-term potentiation, memory and cognition. In this review, we summarize current understanding of apoE function in the brain, with a particular emphasis on its role in synaptic plasticity and the underlying cellular and molecular mechanisms, involving low-density lipoprotein receptor-related protein 1 (LRP1), syndecan, and LRP8/ApoER2.