• Animal cells and systems
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• 제5권3호
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• pp.253-262
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• 2001

Ligand-receptor clustering event is the most important step in leukocyte adhesion and spreading on endothelial cells. Intercellular adhesion molecule-1 (ICAM-1) has been shown to enhance leukocyte adhesion, but the molecular event during the process of adhesion is unclear. To visualize the dynamics of ICAM-1 movement during adhesion, we have engineered stable Chinese hamster ovary cell lines expressing ICAM-1 fused to a green fluorescent protein (IC1_GFP/CHO) and examined them under the fluorescence microscopy. The transfection of IC1_GFP alone in these cells was sufficient to support the adhesion of K562 cells that express $\alpha$L$\beta$2 (LFA-1) integrin stimulated by CBR LFA-1/2 mAb. This phenomenon was mediated by ICAM-1-LFA-1 interactions, as an mAb that specifically inhibits ICAM-1-LFA-1 interaction (RRl/l) completely abolished the adhesion of LFA-1＊ cells to IC1_ GFP/CHO cells. We found that the characteristic of adhesion was followed almost immediately (~10 min) by the rapid accumulation of ICAM-1 on CHO cells at a tight interface between the two cells. Interestingly, ICI_GFP/CHO cells projected plasma membrane and encircled approximately half surface of LFA-1+ cells, as defined by confocal microscopy. This unusual phenomenon was also confirmed on HUVEC after adhesion of LFA-1＊ cells. Neither cytochalasin D nor 2,3-butanedione 2-monoxime an inhibitor of myosin light chain kinase blocked LFA-1-mediated ICAM-1 clustering, indicating that actin cytoskeleton and myosin-dependent contractility are not necessary for ICAM-1 clustering. Taken together, we suggest that leukocyte adhesion to endothelial cells induces specialized form of ICAM-1 clustering that is distinct from immunological synapse mediated by T cell interaction with antigen presenting cells.

• Molecules and Cells
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• 제25권3호
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• pp.385-389
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• 2008

Septins are a family of filament-forming GTP-binding proteins involved in a variety of cellular process such as cytokinesis, exocytosis, and membrane dynamics. Here we report the biochemical and immunocytochemical characterization of a recently identified mammalian septin, SEPT12. SEPT12 binds GTP in vitro, and a mutation (Gly56 to Asn) in the GTP-binding motif abolished binding. Immunocytochemical analysis revealed that wild-type SEPT12 formed filamentous structures when transiently expressed in Hela cells whereas $SEPT12^{G56A}$ generated large aggregates. In addition, wild-type SEPT12 failed to form filaments when coexpressed with $SEPT12^{G56A}$. We also observed that GTP-binding by SEPT12 is required for interaction with SEPT11 but not with itself.

• 한국자기공명학회논문지
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• 제20권3호
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• pp.95-101
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• 2016

Apolipoprotein B-100 (Apo-B100) is a major component of low density lipoprotein (LDL). Apo B-100 protein has 4,536 amino acid sequence and these amino acids are classified into peptide groups A to G with subsequent 20 amino acids (P1-P302). The peptide groups were act as immunoglobulin (Ig) antigens which oxidized via malondialdehyde (MDA). The mimetic peptide P1 (EEEMLENVSLVCPKDAT RFK) out of D-group peptides carrying the highest value of IgG antigens were selected for structural studies that may provide antigen specificity. Circular Dichroism (CD) spectra were measured for peptide secondary structure in the range of 190-250 nm. Experimental results show that P1 exhibit partial of ${\beta}-sheet$ and random coil structure. Homonuclear (COSY, TOCSY, NOESY) 2D-NMR experiments were carried out for NMR signal assignments and structure determination for P1. On the basis of these completely assigned NMR spectra and distance data, distance geometry (DG) and Molecular dynamics (MD) were carried out to determine the structures of P1. The proposed structure was selected by comparisons between experimental NOE spectra and back calculated 2D NOE results from determined structure showing acceptable agreement. The total Root-Mean-Square-Deviation (RMSD) value of P1 obtained upon superposition of all atoms was in the range $0.33{\AA}$. The solution state P1 has mixed structure of ${\beta}-sheet$ (Glu[1] to Cys[12]) and random coil (Pro[13] to Lys[20]). These NMR results are well consistent with secondary structure from experimental results of circular dichroism. Structural studies based on NMR may contribute to the studies of atherosclerosis and observed conformational characteristics of apo B-100 in LDL using monoclonal antibodies.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• 제24권5호
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• pp.432-442
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• 2021

Purpose: The aim of this study was to evaluate the nutrient content consumed by children and adolescents on home-prepared versus chef-prepared specific carbohydrate diets (SCD) as therapy for inflammatory bowel disease (IBD). Methods: Dietary intake of two cohorts with active IBD initiating the SCD over 12 weeks was assessed. The home-prepared cohort received detailed guidance from dietitians on implementation of the SCD. The chef in the other cohort was knowledgeable in the SCD and prepared meals from a fixed set of recipes. Data from 3-day diet diaries at 4 different time points were collected. US Recommended Daily Allowances (RDA) were calculated for macronutrients, vitamins, and minerals. Results: Eight participants on the homemade SCD and 5 participants on the chef-prepared SCD were included in analysis. Mean % RDA for energy intake was 115% and 87% for homemade and chef-prepared groups (p<0.01). Mean % RDA for protein intake was 337% for homemade SCD and 216% for chef-prepared SCD (p<0.01). The homemade SCD group had higher mean % RDA values for vitamin A and iron, while the chef-prepared SCD group had higher intake of vitamins B1, B2, D, phosphorus and zinc (p<0.01 for all). Conclusion: The SCD implemented homemade versus chef-prepared can result in significantly different intake of nutrients and this may influence efficacy of this dietary therapy. Meal preparation dynamics and the motivation of families who pursue dietary treatment may play an important role on the foods consumed and the outcomes on dietary therapy with the SCD.

• Molecules and Cells
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• 제44권2호
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• pp.88-100
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• 2021

Anoctamin 6/TMEM16F (ANO6) is a dual-function protein with Ca2+-activated ion channel and Ca2+-activated phospholipid scramblase activities, requiring a high intracellular Ca2+ concentration (e.g., half-maximal effective Ca2+ concentration [EC50] of [Ca2+]i > 10 μM), and strong and sustained depolarization above 0 mV. Structural comparison with Anoctamin 1/TMEM16A (ANO1), a canonical Ca2+-activated chloride channel exhibiting higher Ca2+ sensitivity (EC50 of 1 μM) than ANO6, suggested that a homologous Ca2+-transferring site in the N-terminal domain (Nt) might be responsible for the differential Ca2+ sensitivity and kinetics of activation between ANO6 and ANO1. To elucidate the role of the putative Ca2+-transferring reservoir in the Nt (Nt-CaRes), we constructed an ANO6-1-6 chimera in which Nt-CaRes was replaced with the corresponding domain of ANO1. ANO6-1-6 showed higher sensitivity to Ca2+ than ANO6. However, neither the speed of activation nor the voltage-dependence differed between ANO6 and ANO6-1-6. Molecular dynamics simulation revealed a reduced Ca2+ interaction with Nt-CaRes in ANO6 than ANO6-1-6. Moreover, mutations on potentially Ca2+-interacting acidic amino acids in ANO6 Nt-CaRes resulted in reduced Ca2+ sensitivity, implying direct interactions of Ca2+ with these residues. Based on these results, we cautiously suggest that the net charge of Nt-CaRes is responsible for the difference in Ca2+ sensitivity between ANO1 and ANO6.

• BMB Reports
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• 제54권12호
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• pp.592-600
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• 2021

Parkinson's disease (PD) is one of the most common neurodegenerative diseases in the elderly population and is caused by the loss of dopaminergic neurons. PD has been predominantly attributed to mitochondrial dysfunction. The structural alteration of α-synuclein triggers toxic oligomer formation in the neurons, which greatly contributes to PD. In this article, we discuss the role of several familial PD-related proteins, such as α-synuclein, DJ-1, LRRK2, PINK1, and parkin in mitophagy, which entails a selective degradation of mitochondria via autophagy. Defective changes in mitochondrial dynamics and their biochemical and functional interaction induce the formation of toxic α-synuclein-containing protein aggregates in PD. In addition, these gene products play an essential role in ubiquitin proteasome system (UPS)-mediated proteolysis as well as mitophagy. Interestingly, a few deubiquitinating enzymes (DUBs) additionally modulate these two pathways negatively or positively. Based on these findings, we summarize the close relationship between several DUBs and the precise modulation of mitophagy. For example, the USP8, USP10, and USP15, among many DUBs are reported to specifically regulate the K48- or K63-linked de-ubiquitination reactions of several target proteins associated with the mitophagic process, in turn upregulating the mitophagy and protecting neuronal cells from α-synuclein-derived toxicity. In contrast, USP30 inhibits mitophagy by opposing parkin-mediated ubiquitination of target proteins. Furthermore, the association between these changes and PD pathogenesis will be discussed. Taken together, although the functional roles of several PD-related genes have yet to be fully understood, they are substantially associated with mitochondrial quality control as well as UPS. Therefore, a better understanding of their relationship provides valuable therapeutic clues for appropriate management strategies.

• BMB Reports
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• 제57권6호
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• pp.293-298
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• 2024

Microtubule acetylation has been shown to regulate actin filament dynamics by modulating signaling pathways that control actin organization, although the precise mechanisms remain unknown. In this study, we found that the downregulation of microtubule acetylation via the disruption ATAT1 (which encodes α-tubulin N-acetyltransferase 1) inhibited the expression of RhoA, a small GTPase involved in regulating the organization of actin filaments and the formation of stress fibers. Analysis of RHOA promoter and chromatin immunoprecipitation assays revealed that C/EBPβ is a major regulator of RHOA expression. Interestingly, the majority of C/EBPβ in ATAT1 knockout (KO) cells was found in the nucleus as a 27-kDa fragment (referred to as C/EBPβ^p27) lacking the N-terminus of C/EBPβ. Overexpression of a gene encoding a C/EBPβ^p27-mimicking protein via an N-terminal deletion in C/EBPβ led to competitive binding with wild-type C/EBPβ at the C/EBPβ binding site in the RHOA promoter, resulting in a significant decrease of RHOA expression. We also found that cathepsin L (CTSL), which is overexpressed in ATAT1 KO cells, is responsible for C/EBPβ^p27 formation in the nucleus. Treatment with a CTSL inhibitor led to the restoration of RHOA expression by downregulation of C/EBPβ^p27 and the invasive ability of ATAT1 KO MDA-MB-231 breast cancer cells. Collectively, our findings suggest that the downregulation of microtubule acetylation associated with ATAT1 deficiency suppresses RHOA expression by forming C/EBPβ^p27 in the nucleus through CTSL. We propose that CTSL and C/EBPβ^p27 may represent a novel therapeutic target for breast cancer treatment.

• 한국식품영양과학회지
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• 제29권1호
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• pp.174-179
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• 2000

우리 나라에서 활발히 양식되고 있는 양직산과 자연산 넙치의 맛성분 조성을 비교하기 위하여 맛과 관계가 깊은 함질소 엑스성분을 분석하여 비교한 결과는 다음과 같다. 일반성분 중 수분은 양식산이 자연산보다 다소 낮은 반면 단백질과 지질은 다소 높았다. 엑스분 질소는 자연산이 다소 높았다. 유리아미노산은 양식산에서 31종, 자연산에서 36종이 검출되어 자연산이 더 다양한 아미노산 조성을 보였으며, 그 총량은 양식산 자연산 모두 전반적으로 낮은 수준이었다. 넙치의 taurine 함량은 양식산과 자연산에서 각각 115 mg과 91 mg으로 유리아미노산 중 가장 높았으며, 우리아미노산 총량의 각각 57.0%와 37.0%를 차지하였다. 양식산에서 함량이 많은 유리아미노산으로서는 taurine, alanine, asparagine, glutamine, glutamic acid, lysine 등이었고, 자연산에서는 taurine, lysine, alanine, carnosine, hydroxyproline 등이었다. 넙치는 oligopeptide류 함량이 869 mg과 1,063 mg으로서 유리아미노산 총량의 4.3배에 달하였다. ATP관련 화합물의 총량은 각각 $9.56\;\mumol과\;6,58\;\mumol$로서 양식산이 다소 높았으며 IMP가 각각 68.2%와 78.6%로서 대부분을 차지하였다. TMAO는 각각 273 mg과 316 mg으로서 자연산이 높고, creatine은 각각 522 mg와 487 mg으로서 양식산이 높았다. Betaine류, TMA, creatinine은 모두 미량이었다. 엑스분 중의 질소분포는 creatine과 creatinine 질소가 가장 높고, 다음은 oligopeptide류 질소, TMAO와 TMA질소, ATP관련 물질 질소, 유리아미노산 질소의 순이었고 질소의 회수율은 95% 이상이었다.취상태를 평가받고 과부족이 되기 쉬운 영양소의 급원 식품과 음식에 대한 영양정보도 제공받을 수 있도록 할 뿐 아니라 식이요법을 필요로 하는 질환의 영양상담을 위한 기본 프로그램으로 활용될 수 있도록 하는데 그 의의가 있다.사만을 선택하여 성별과 결혼여부에 따라 환경친화적 음식소비 행동의 차이를 알아보기 위한 결과 역시 차이를 보이지 않았다. 환경친화적 음식소비행동은 연령, 월평균소득 및 엥겔계수와 의미 있는 상관관계를 보이지 않았다. 조리사와 주부는 음식을 소비하는 전 과정에서 가장 많이 관여하고 있는 집단이다. 그런데 조리사와주부 모두 전반적으로 환경친화적 음식소비행동의 수준이 높지 않음으로 합리적인 식생활문화를 생활화 할 수 있도록 교육과 홍보가 필요하다고 본다. 주부의 경우 유치원이나 어린이집, 초중고둥학교에서 하는 부모교육과 반상회의 홍보자료에 반상회의 홍보자료에 반드시환경친화적 음식소비행동에 관한 교육이 포함되어야 한다. 조리사의 경우 정기교육과정에 환경친화적 음식소비행동에 관한 홍보를 함께 함으로써 외식이나 단체급식에서 발행하는 음식물 쓰레기의 양을 줄 일 수 있을 것이다.m its genes controlling host specificity to its population sturctures and dynamics, have begun to provide new insights into the potential mechanisms underlying race variation. In this review we aim to provide an overview on (a) the molecular basis of host specificity of M. grisea, (b) the population structure and dynamics of rice pathogens, and (c) the nature and mechanisms

• 분석과학
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• 제32권6호
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• pp.262-270
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• 2019

뼈에서 추출된 콜라겐의 탄소와 질소 안정동위원소 정보는 그 당시의 사람들이 섭취했던 식생활, 영양 상태, 고환경과 생활상을 연구하는데 중요한 역할을 한다. 본 연구에서는 출토 자료가 희박하여 아직까지 시도된 바가 없는 고려시대 피장자들에 대한 식생활과 모유수유 양상을 밝히고자 한다. 고려시대 경주 동궁과 월지 3호 우물에서 출토된 옛사람 뼈 4개체에서 추출된 뼈 콜라겐을 이용하여 안정동위원소 분석을 진행하였으며, 탄소와 질소 안정동위원소 분석 결과는 각각 다음과 같다(δ¹³C(‰) = -19.5 ± 0.9 ‰, δ¹⁵N(‰) = 11.1 ± 1.1 ‰, (n = 4)). 탄소 안정동위원소 분석 결과 벼, 보리 등 C₃ 작물군을 주로 섭취하였고, 질소 안정동위원소 분석 결과 동물성 단백질은 주로 육상 동물로부터 얻었을 가능성이 높다고 추정된다. 또한, 출토된 옛사람 뼈 4개체는 성인, 소아, 유아, 영아로 추정되는 다양한 연령대로 나타났으며, 유아와 영아로 추정되는 피장자들과 성인 피장자 간의 질소 안정동위원소 값 차이로부터 약 3세의 연령까지 모유수유가 진행되고 있었다고 추정된다. 모유수유와 이유 양상은 당시의 출산율, 인구역학, 이동 패턴, 질병 등 다양한 사회상을 반영하는 매우 중요한 정보이며, 다양한 연령대의 분석 결과로부터 의미 있는 정보를 밝혀냈다.

• Asian-Australasian Journal of Animal Sciences
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• 제21권6호
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• pp.807-817
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• 2008

Steers with ad libitum access to rice straw were assigned to four diets to evaluate the effects of maize or soybean hull supplementation on intake, in vivo digestibility, ruminal pH, VFA, ammonia-nitrogen ($NH_3-N$) and in situ ruminal disappearance of feed nutrients by cattle consuming rice straw. Supplement treatments were: no supplement (RS); soybean meal at 0.127% BW (SBM); cracked maize at 0.415% BW plus 0.044% BW soybean meal (MAIZE); or soybean hulls at 0.415% BW plus 0.044% BW soybean meal (HULLS). The MAIZE and HULLS diets were formulated to provide approximately 4 MJ of $NE_m$ per kg of diet. Rice straw DMI was not affected (p = 0.34) by supplement. Apparent dry matter (DM) digestibility was greater (p<0.001) for MAIZE and HULLS (56.6 and 60.0%, respectively) than for steers consuming SBM or RS (51.8 and 44.4%, respectively). Apparent NDF digestibility was greater (p<0.0004) for HULLS than MAIZE (61.7 vs. 58.0%, respectively) and apparent ADF digestibility was greater (p<0.0008) for HULLS than MAIZE (61.1 vs. 49.2%, respectively). There was no difference in apparent hemicellulose digestibility (p = 0.43). Analysis of ruminal fluid collected 0, 2, 4, 6, and 8 h post-feeding revealed ammonia-nitrogen was greatest (p<0.05) for steers on SBM and HULLS diets at 2 h (24.08 and 22.57 mg/dl, respectively) and total volatile fatty acids was greatest (p<0.05) for HULLS at 4 h (230 mM/L). In situ disappearance, measured at 0, 2, 4, 6, 8, 16 and 24 h, indicated that SBM, MAIZE and HULLS tended to enhance the digestibility of DM and fiber components of rice straw. In situ disappearance of rice straw DM was greatest for SBM and/or HULLS from 4 to 24 h (p = 0.03). Rice straw NDF and ADF disappearance was enhanced by supplementation from 16 to 24 h (p<0.02). Rice straw DM, NDF and ADF disappearances at 24 h were similar for MAIZE and HULLS treatments. When feeding cattle rice straw diets, energy and protein-based supplements are essential. This study showed that fiber-based supplements are just as, if not more, effective as starch-based supplements in rice straw utilization. This study shows that soybean hulls, in spite of their high fiber content, are as efficient as maize for supplementing rice straw primarily because fiber in soybean hulls is highly digestible as shown by in vivo digestibility and in situ disappearance.