• BMB Reports
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• 제54권3호
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• pp.164-169
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• 2021

Neuronal growth regulator 1 (NEGR1) is a GPI-anchored membrane protein that is involved in neural cell adhesion and communication. Multiple genome wide association studies have found that NEGR1 is a generic risk factor for multiple human diseases, including obesity, autism, and depression. Recently, we reported that Negr1-/- mice showed a highly increased fat mass and affective behavior. In the present study, we identified Na/K-ATPase, beta1-subunit (ATP1B1) as an NEGR1 binding partner by yeast two-hybrid screening. NEGR1 and ATP1B1 were found to form a relatively stable complex in cells, at least partially co-localizing in membrane lipid rafts. We found that NEGR1 binds with ATP1B1 at its C-terminus, away from the binding site for the alpha subunit, and may contribute to intercellular interactions. Collectively, we report ATP1B1 as a novel NEGR1-interacting protein, which may help deciphering molecular networks underlying NEGR1-associated human diseases.

• The Korean Journal of Physiology and Pharmacology
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• 제17권4호
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• pp.275-281
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• 2013

Astrocytes are reported to have critical functions in ischemic brain injury including protective effects against ischemia-induced neuronal dysfunction. Na-K ATPase maintains ionic gradients in astrocytes and is suggested as an indicator of ischemic injury in glial cells. Here, we examined the role of the Na-K ATPase in the pathologic process of ischemic injury of primary cultured astrocytes. Chemical ischemia was induced by sodium azide and glucose deprivation. Lactate dehydrogenase assays showed that the cytotoxic effect of chemical ischemia on astrocytes began to appear at 2 h of ischemia. The expression of Na-K ATPase ${\alpha}1$ subunit protein was increased at 2 h of chemical ischemia and was decreased at 6 h of ischemia, whereas the expression of ${\alpha}1$ subunit mRNA was not changed by chemical ischemia. Na-K ATPase activity was time-dependently decreased at 1, 3, and 6 h of chemical ischemia, whereas the enzyme activity was temporarily recovered to the control value at 2 h of chemical ischemia. Cytotoxicity at 2 h of chemical ischemia was significantly blocked by reoxygenation for 24 h following ischemia. Reoxygenation following chemical ischemia for 1 h significantly increased the activity of the Na-K ATPase, while reoxygenation following ischemia for 2 h slightly decreased the enzyme activity. These results suggest that the critical time for ischemia-induced cytotoxicity of astrocytes might be 2 h after the initiation of ischemic insult and that the increase in the expression and activity of the Na-K ATPase might play a protective role during ischemic injury of astrocytes.

• The Korean Journal of Physiology
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• 제30권2호
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• pp.257-267
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• 1996

Diabetes mellitus is associated with a wide range of pathophysiologic changes in the kidney. This study was designed to examine the mechanisms by which glucose modulates the expression of polarized membrane transport functions in primary cultured rabbit renal proximal tubule cells. Results are as follows: The rate of 30 minute $Rb^{+}$ uptake was significantly higher($137.76{\pm}5.40%$) in primary renal tubular cell cultures treated with 20 mM glucose than that of 5 mM glucose. Not the level of mRNA for the ${\alpha}$ subunit of Na, K-ATPase but that of ${\beta}$ subunit was elevated in primary cultures treated with high glucose. The initial rate of methyl-${\alpha}$-D-glucopyranoside(${\alpha}$-MG) uptake was significantly lower($71.91{\pm}3.02%$) in monolayers treated with 20 mM glucose than that of 5 mM glucose. There was a tendency of an increase in phlorizin binding site in cells treated with 5 mM glucose. However, 3-O-methyl-D-glucose(3-O-MG) uptake was not affected by glucose concentration in culture media. TPA inhibited $Rb^{+}$ uptake by $63.61{\pm}1.94\;and\;45.80{\pm}1.36%$ and ${\alpha}$-MG uptake by $48.54{\pm}3.69\;and\;41.87{\pm}6.70%$ in the cells treated with 5 and 20 mM glucose, respectively. Also TPA inhibited mRNA expression of Na/glucose cotransporter in cells grown in 5mM glucose medium. cAMP significantly stimulated ${\alpha}$-MG uptake by $114.65{\pm}5.70%$ in cells treated with 5mM glucose, while it did not affect ${\alpha}$-MG uptake in cell treated with 20 mM glucose. However, cAMP inhibited $Rb^{+}$ uptake by $76.69{\pm}4.16\;and\;66.87{\pm}2.41%$ in cells treated with 5 and 20 mM glucose, respectively. In conclusion, the activity of the renal proximal tubular Na,K-ATPase is elevated in high glucose concentration. In contrast, the activity of the Na/glucose cotransport system is inhibited. High glucose may in part affect the activity of the Na,K-ATPase and the Na/glucose cotransport system by controlling the protein kinase C and/or A signal transduction pathway in primary cultured renal proximal tubule cells.

• The Korean Journal of Physiology
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• 제19권1호
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• pp.15-23
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• 1985

$(Na^++K^+)-ATPase$은 ${\alpha}$ 와 ${\beta}$의 두 subunits로 구성되어 있으며, 분자량이 약 300,000 daltons 정도되는 것으로 보아 ${\alpha}_2{\beta}_2$의 형태로 존재할 것으로 알려져 왔다 한편, 사람 적혈구막에 있는 $Na^+,\;K^+\;Pump$는 glycolytic enzymes과 complex를 이루고 있으리라는 보고도 있다. 우리는 이 실험에서 in situ상태의 사람 적혈구막$(Na^++K^+)-ATPase$의 분자량을 측정하기 위하여, 소위 말하는 ‘Target theory’를 radiation에 의한 ouabain sensitive한 $\Na^+$이동과, intact한 cells과 ghosts에서의 ATP가수분해능력의 inactivation data에 적용하였다. Intact한 cells은 cryoprotective agent의 존재하에서, ghosts는 직접적으로 액화질소의 용기속에 담고 온도를 $-45^{\circ}C$에서 $-50^{\circ}C$로 유지시키면서 1.5 MeV의 electron beam으로 조사한 후에 Pump의 기능내지 효소의 활성도를 측정하여 radiation에 따르는 inactivation의 정도를 측정하였다. 이득 활성도는 radiation의 양에 따라 simple exponential function으로 inactivation되었으며, 이로부터 radiation sensitive volume(target size)를 계산하였다. Target size는 intact한 cells을 사용하였을 경 우$(Na^++K^+)-ATPase$나 $Na^+,\;K^+\;Pump$ 모두 600,000 daltons으로 계산되었으며, 이 값은 만약 cells을 strophanthidin으로 먼저 처치하고 측정하면 약 325,000 daltons으로 감소하였다. Ghosts를 사용했을 경우에도$(Na^++K^+)-ATPase$의 target size는 역시 약 325,000 daltons이었다. 이상의 결과로 미루어 보아 intact한 cells에서는 $(Na^++K^+)-ATPase/Na^+,\;K^+\;Pump$가 $(\alpha\beta)_2$의 dimer 상태로 존재하거나 혹은 $(\alpha\beta)_2$의 monomer에 glycolytic enzymes과 같은 다른 enzymes이 붙어 functional한 구조를 이루고 있는 것이 아닌가 사료된다. 또한 실헐성적은 이러한 dimeric association 혹은 heterocomplex association은 ghost를 만드는 과정에서나 strophanthidin의 처치로 부서질 수 있음을 암시하고 있다.

• Journal of Radiation Protection and Research
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• 제30권4호
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• pp.197-208
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• 2005

Although little information is available on the underlying mechanisms, various genetic factors have been associated with tissue-specific responses to radiation. In the present study, we explored the possibility whether organ specific gene expression is associated with radiosensitivity using samples from brain, lung and spleen. We examined intrinsic expression pattern of 23 genes in the organs by semi-quantitative RT-PCR method using both male and female C57BL/6 mice. Expression of p53 and p21, well known factors for governing sensitivity to radiation or chemotherapeutic agents, was not different among the organ types. Both higher expression of sialyltransferase, delta7-sterol reductase, leptin receptor splice variant form 12.1, and Cu/Zn superoxide dismutase (SOD) and lower expression of alphaB crystalline were specific for spleen tissue. Expression level of glutathione peroxidase and APO-1 cell surface antigen gene in lung tissue was high, while that of Na, K-ATPase alpha-subunit, Cu/ZnSOD, and cyclin G was low. Brain, radioresistant organ, showed higher expressions of Na, K-ATPase-subunit, cyclin G, and nucleolar protein hNop56 and lower expression of delta7-sterol reductase. The result revealed a potential correlation between gene expression patterns and organ sensitivity, and Identified genes which might be responsible for organ sensitivity.

• 한국미생물·생명공학회지
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• 제33권4호
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• pp.255-259
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• 2005

본 실험에서는 HRF의 조절단백질을 알아보기 위해 HRF를 bait로 한 yeast two hybrid assay를 실행한 결과 해당과정에 관여하는 TPI(triosephosphate isomerase)라는 효소를 발견하였으며, 가장 많이 중복되어 있었다. In vitro에서 HRF는 TPI의 C말단 잔기 부근(아미노산 156-249)이 상호작용에 주로 관여하는 부위임을 알 수 있었다. 또한, HeLa 세포에서 immunoprecipitation을 이용하여 HRF와 TPI의 상호작용이 실제 in vivo에서도 일어나는 현상이라는 것을 밝혔다. 결과적으로 HRF와 TPI 상호작용은 세포내 일정량이 존재하며 여러가지 신호전달에 의해 동시에 Na,K-ATPase와도 상호작용하는 것으로 생각된다.

• BMB Reports
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• 제38권3호
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• pp.307-313
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• 2005

Thiobacillus ferrooxidans is one of the most important bacterium used in bioleaching, and can utilize $Fe^{2+}$ or sulphide as energy source. Growth curves for Thiobacillus ferrooxidans have been tested, which show lag, logarithmic, stationary and aging phases as seen in other bacteria. The logarithmic phases were from 10 to 32 hours for Thiobacillus ferrooxidans cultivated with $Fe^{2+}$ and from 4 to 12 days for Thiobacillus ferrooxidans cultivated with elemental sulphur. Differences of protein patterns of Thiobacillus ferrooxidans growing on elemental sulphur and $Fe^{2+}$ separately were investigated after cultivation at $30^{\circ}C$ by the analysis of two-dimensional gel electrophoresis (2-DE), matrix-assisted laser desorption/ ionization (MALDI)-Mass spectrometry and ESI-MS/MS. From the 7 identified protein spots, 11 spots were found more abundant when growing on elemental sulphur. By contrast 6 protein spots were found decreased at elemental cultivation condition. Among the proteins identified, cytochrome C have been previously identified as necessary elements of electron-transfering pathway for Thiobacillus ferrooxidans to oxidize $Fe^{2+}$; ATP synthase alpha chain and beta are expressed increased when Thiobacillus ferrooxidans cultivated with $Fe^{2+}$ as energy source. ATP synthase Beta chain is the catalytic subunit, and ATP synthase alpha chain is a regulatory subunit. The function of ATPase produces ATP from ADP in the presence of a proton gradient across the membrane.

• 한국균학회지
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• 제44권3호
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• pp.201-205
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• 2016

2015년 8월경 강원도 영월군의 고려엉겅퀴 재배 농가에서 잎에 소형 점무늬 증상이 발생하였다. 초기에는 고려엉겅퀴 잎에 회갈색 내지 갈색의 작은 점이 나타나며, 병이 진전되면 부정형의 진한 갈색의 병반으로 커지면서 크게 확대되고 결국 잎 전체가 진한 갈색 내지 흑색으로 변하였다. 병든 잎에서 Stemphylium균이 분리되었으며, 분생포자 크기와 분생포자경의 길이 등을 고려한 균학적 특성에 의해 Stemphylium lycopersici 혹은 Stemphylium solani, Stemphylium xanthosomatis와 유사한 것으로 나타났다. Ribosomal internal transcribed spacer (ITS) 영역, elongation factor 1 alpha (EF-$1{\alpha}$), glyceraldehydes-3-phosphate dehydrogenase (gpd), vacuolar membrane ATPase catalytic subunit A gene (vmaA)와 vacuolar biogenesis gene (vpsA) 사이의 noncoding 영역을 대상으로 한 다자위 염기서열 분석에 의해 분리균은 모두 S. lycopersici로 확인되었다. 고려엉겅퀴 잎을 대상으로 상처구와 무상처구로 나누어 분리균의 포자 현탁액을 접종하여 병원성을 확인한 결과, 접종 3일 후부터 상처의 유무에 관계없이 분리균을 접종한 부위에서 병반이 관찰되었다. 따라서 본 결과를 토대로 본 병을 S. lycopersici에 의한 고려엉겅퀴 점무늬병으로 명명하며, 고려엉겅퀴 점무늬병의 발생을 국내 최초로 보고한다.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제31권1호
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• pp.24-30
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• 2005

타액선에서 교감 신경과 부교감 신경이 나트륨 운반체와 수분 통로의 조절에 어떠한 기능을 하는지 알아 보고자 흰쥐 악하선을 지배하는 교감 신경과 부교감 신경을 절제하고 나서 타액선내 나트륨 운반체와 수분 통로의 발현을 조사하여 다음과 같은 성적을 얻었다. 1. Na,K-ATPase의 ${\alpha}1,\;{\beta}1$ 소단위는 교감 신경 절제에 의해 크게 영향받지 않았으나 부교감 신경 절제에 의해서는 두 소단위의 발현이 모두 감소되었다. 2. ENaC ${\alpha}-,\;{\beta}-,\;{\gamma}-$ 소단위는 그 발현이 교감 신경 절제에 의해 영향 받지 않았으나 부교감 신경 절제에 의해서 도리어 증가하였다. 3. NHE3는 교감 신경 및 부교감 신경 절제에 의해 모두 크게 감소했다. 4. 교감 신경 절제시 AQP1의 발현이 크게 증가했으나, 부교감 신경 절제시 영향 받지 않았다. 5. 교감 신경 절제 및 부교감 신경 절제는 AQP4 발현을 크게 증가시켰다. 6. AQP5는 교감 신경 절제시 영향을 받지 않았으나, 부교감 신경 절제시 크게 감소되었다. 이상의 실험성적을 요약할 때 악하선을 지배하는 교감 신경 및 부교감 신경은 선의 나트륨 운반체 및 수분 통로 발현에 긴장성 조절을 영위함으로써 타액의 전해질 및 수분 조성을 결정하는 데 공헌함을 알 수 있다. 그리고 이 신경의 절제시 보이는 나트륨 운반체와 수분 통로의 변화는 기능적으로 신경 절제 타액선에서의 타액 분비량과 타액의 무기질 조성 변화의 원인이 될 것이라 생각된다.

• The Korean Journal of Physiology and Pharmacology
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• 제15권6호
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• pp.383-388
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• 2011

Regulators of G-protein signaling (RGS) proteins are regulators of $Ca^{2+}$ signaling that accelerate the GTPase activity of the G-protein ${\alpha}$ -subunit. RGS1, RGS2, RGS4, and RGS16 are expressed in the pancreas, and RGS2 regulates G-protein coupled receptor (GPCR)-induced $Ca^{2+}$ oscillations. However, the role of RGS4 in $Ca^{2+}$ signaling in pancreatic acinar cells is unknown. In this study, we investigated the mechanism of GPCR-induced $Ca^{2+}$ signaling in pancreatic acinar cells derived from $RGS4^{-/-}$ mice. $RGS4^{-/-}$ acinar cells showed an enhanced stimulus intensity response to a muscarinic receptor agonist in pancreatic acinar cells. Moreover, deletion of RGS4 increased the frequency of $Ca^{2+}$ oscillations. $RGS4^{-/-}$ cells also showed increased expression of sarco/endoplasmic reticulum $Ca^{2+}$ ATPase type 2. However, there were no significant alterations, such as $Ca^{2+}$ signaling in treated high dose of agonist and its related amylase secretion activity, in acinar cells from $RGS4^{-/-}$ mice. These results indicate that RGS4 protein regulates $Ca^{2+}$ signaling in mouse pancreatic acinar cells.