• Korean Journal of Microbiology
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• v.46 no.1
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• pp.104-108
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• 2010

We describe the construction of derivatives of wild type and mutant lrp genes that encode 6XHis-tag Lrps. These derivatives of wild type and mutant Lrp could be useful for in vitro studies including Lrp conformational changes. We show that 6XHis-tag Lrp wild type and 6XHis-tag Lrp R145W bind with similar patterns in vitro to 21 bp duplex DNA containing the consensus sequences of Lrp sites of upstream of the ilvIH operon. In addition, we report here the 6XHis-tag Lrp R145W is useful to investigate the conformational changes of Lrp in solution by using its own intrinsic fluorescence characteristics.

• Reproductive and Developmental Biology
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• v.29 no.1
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• pp.19-24
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• 2005

The low density lipoprotein receptor-related protein 5 (LRP5) highly expressed in many tissues, including hepatocytes and pancreatic beta cells, can bind to apolipoprotein E. To evaluate in vivo roles of LRP5, we generated LRP5-deficient mice. LRP5 genomic DNA was isolated from TT2 embryonic stem (ES) cells. Targeting vector was constructed to disrupt an exon 18 of the mouse LRP5 gene and transfected into ES cells. Three homologous recombinants at LRP5 locus were identified from 178 G418-resistant clones. Chimeric males generated by morula aggregation technique were mated to C57BL/6 female mice. After achieving germ-line transmission, LRP5+/- females were crossed with LRP5+/- males to obtain LRP5-deficient mice. One line of mice lacking LRP5 gene was confirmed by Southern blotting. Such knock-out mice may serve as an effective animal model to study in vivo function of LRP5 gene.

• 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.

• Biomolecules & Therapeutics
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• v.29 no.5
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• pp.527-535
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• 2021

Sclerostin (SOST), a regulator of bone formation in osteocytes, inhibits the canonical Wnt signaling by interacting with low-density lipoprotein receptor-related protein 5/6 (LRP5/6) to prevent Wnt binding. Loss-of-function mutations of the SOST gene caused massive bone outgrowth and SOST-null mouse exhibited a high bone density phenotype. Therefore, SOST has been suggested as a promising therapeutic target for osteoporosis. A few previous studies with X-ray crystallography identified the binding interfaces between LRP6 and SOST, but there are limitations in these studies as they used truncated SOST protein or SOST peptide. Here, we analyzed the conformational dynamics of SOST-LRP6 E1E2 complex using hydrogen/deuterium exchange mass spectrometry (HDX-MS). We examined the effect of the C-terminal tail of SOST on LRP6 conformation upon complex formation. HDX-MS analysis suggested a new potential binding interface for the C-terminal region of SOST that was missing from the previous crystal structure of the SOST-LRP6 E1E2 complex.

• BMB Reports
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• v.49 no.7
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• pp.357-358
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• 2016

Merlin, encoded by the NF2 gene, is a tumor suppressor that exerts its function via inhibiting mitogenic receptors at the plasma membrane. Although multiple mutations in Merlin have been identified in Neurofibromatosis type II (NF2) disease, its molecular mechanism is not fully understood. Here, we show that Merlin interacts with LRP6 and inhibits LRP6 phosphorylation, a critical step for the initiation of Wnt signaling. We found that treatment of Wnt3a caused phosphorylation of Merlin by PAK1, leading to detachment of Merlin from LRP6 and allowing the initiation of Wnt/β-catenin signaling. A higher level of β-catenin was found in tissues from NF2 patients. Enhanced proliferation and migration caused by knockdown of Merlin in glioblastoma cells were inhibited by suppression of β-catenin. Conclusively, these results suggest that sustained Wnt/β-catenin signaling activity induced by abrogation of Merlin-mediated inhibition of LRP6 phosphorylation might be a cause of NF2 disease.

• Proceedings of the KSAR Conference
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• 2002.06a
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• pp.82-82
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• 2002

The Wnt signaling pathway plays pivotal roles in embryonic development and oncogenesis through various signaling molecules inculding Frizzled receptor, recently characterized LRP5/6 and Dickkopf protein. Although Wnt signaling has been characterized in both developmental and oncogenic processes, little is known about its function in the normal adult. The ability of LRP5 to bind apolipoprotein E(apoE) and the abundant expression of LRP5 transcripts in hepatocytes, raise the possibility that LRP5 plays a role in the hepatic clearance of ApoE-containing chylomicron remonants, a major plasma lipoprotein carrying diet-derived cholesterol. (omitted)

• The Korean Journal of Physiology and Pharmacology
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• v.19 no.3
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• pp.235-240
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• 2015

Androgen receptor (AR) signaling is important for prostate cancer (PCa) cell proliferation. Here, we showed that proliferation of hormone-sensitive prostate cancer cells such as LNCaP was significantly enhanced by testosterone stimulation whereas hormone-insensitive prostate cancer cells such as PC3 and VCaP did not respond to testosterone stimulation. Blocking of AR using bicalutamide abolished testosterone-induced proliferation of LNCaP cells. In addition, knockdown of AR blocked testosterone-induced proliferation of LNCaP cells. Basal expression of low-density lipoprotein receptor-related protein 6 (LRP6) was elevated in VCaP cells whereas stimulation of testosterone did not affect the expression of LRP6. However, expression of LRP6 in LNCaP cells was increased by testosterone stimulation. In addition, knockdown of LRP6 abrogated testosterone-induced proliferation of LNCaP cells. Given these results, we suggest that androgen-dependent expression of LRP6 plays a crucial role in hormone-sensitive prostate cancer cell proliferation.

• 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.

• 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.

• 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.