Functional analysis of cellular localization and complex formation of protein O-mannosyltransferases in Hansenula polymorpha

Hyunah Kim,Dong-jik Lee,Doo-Byoung Oh,Ohsuk Kwon,HyunAh Kang 한국당과학회 2011 한국당과학회 학술대회 Vol.2011 No.1

Protein O-mannosylation is evolutionarily conserved essential protein modification from bacteria to humans, which is initiated in the ER by protein O-mannosyltransferases (PMTs) that catalyze the transfer of mannose from Dol-P-Man to Ser/Thr residues of secretory proteins. We identified and characterized five PMT subfamily genes, PMT1.1, PMT1.2, PMT2, PMT4 and PMT6 in the thermotolerant methylotrophic yeast Hansenula polymorpha. The hydropathy profile analysis predicts all H. polymorpha Pmt proteins to be integral membrane proteins with multiple transmembrane domains. For confirmation of subcellular localization of HpPmt proteins and characterization of PMT complexes, we constructed a set of HA or FLAG epitope-tagged versions of H. polymorpha Pmt proteins. All the C-terminal epitope-tagged HpPmt proteins were shown to be fully functional in vivo and to localize at the ER/Golgi membrane, except for Pmt6p. The significant sensitivity of Hppmt1.2 strain to the PMT1 inhibitor R3A-1c suggested that HpPMT1.2 might have a minor function redundant with HpPMT1.1. However, co-immunoprecipitation experiments using monoclonal anti-HA or anti-Flag bead revealed the complex formation between HpPmt1.1p and HpPmt2p, but no interaction between HpPmt1.2p and HpPmt2p even in the absence of HpPmt1.1p. The results strongly support the notion that interaction with HpPmt2p is required for the full mannosyltransferase activity of HpPmt1.1p, which plays a major role in O-mannosylation essential for cell wall integrity in H. polymorpha.

Sodium-Glucose Cotransporter-2 Inhibitor-Related Diabetic Ketoacidosis: Accuracy Verification of Operational Definition

Kang Dong Yoon,Kim Hyunah,Ko SooJeong,Kim HyungMin,Shinn Jiwon,Kang Min-Gyu,Byeon Sun-ju,Choi Jeong-Hee,Shin Soo-Yong,Kim Hun-Sung 대한의학회 2022 Journal of Korean medical science Vol.37 No.7

Background: The most important aspect of a retrospective cohort study is the operational definition (OP) of the disease. We developed a detailed OP for the detection of sodiumglucose cotransporter-2 inhibitors (SGLT2i) related to diabetic ketoacidosis (DKA). The OP was systemically verified and analyzed. Methods: All patients prescribed SGLT2i at four university hospitals were enrolled in this experiment. A DKA diagnostic algorithm was created and distributed to each hospital; subsequently, the number of SGLT2i-related DKAs was confirmed. Then, the algorithm functionality was verified through manual chart reviews by an endocrinologist using the same OP. Results: A total of 8,958 patients were initially prescribed SGLT2i. According to the algorithm, 0.18% (16/8,958) were confirmed to have SGLT2i-related DKA. However, based on manual chart reviews of these 16 cases, there was only one case of SGLT2i-related DKA (positive predictive value = 6.3%). Even after repeatedly narrowing the diagnosis range of the algorithm, the effect of a positive predictive value was insignificant (6.3–10.0%, P > 0.999). Conclusion: Owing to the nature of electronic medical record data, we could not create an algorithm that clearly differentiates SGLT2i-related DKA despite repeated attempts. In all retrospective studies, a portion of the samples should be randomly selected to confirm the accuracy of the OP through chart review. In retrospective cohort studies in which chart review is not possible, it will be difficult to guarantee the reliability of the results.

Reliability of Human Lim Impedance Estimation of HapticMaster

Hyunah Kang,Sung Shin Kim,Sang Hoon Kang 대한기계학회 2019 대한기계학회 춘추학술대회 Vol.2019 No.4

Childhood traumatic experiences and peer bullying victimization among Korean adolescents in out‐of‐home care: The mediating effect of aggression

Kang Hyunah 한국사회복지학회 2021 Asian Social Work and Policy Review Vol.15 No.3

How do physical health problems of Korean adolescents in out-of-home care affect their psychosocial adaptations? The mediation of bullying victimization experiences

Kang, Hyunah,Chun, JongSerl,Nho, Choong Rai,Woo, Seokjin,Chung, Ick-Joong Elsevier 2018 CHILDREN AND YOUTH SERVICES REVIEW - Vol.94 No.-

<P><B>Highlights</B></P> <P> <UL> <LI> Children in out-of-home care are known to suffer from various physical health problems. </LI> <LI> Poor health status would force the children in care into vulnerable positions of being bullied at school. </LI> <LI> The study data are obtained from the Panel Study on Korean Children in Out-of-Home Care. </LI> <LI> The study finds that physical health problems negatively affect self-esteem, depression and anxiety, and social withdrawal. </LI> <LI> The influence of physical health problems is mediated on depression and anxiety through bullying victimization. </LI> </UL> </P>

가정위탁아동의 양육환경과 장기적 발달성과

강현아(Hyunah Kang),정익중(Ick Joong Chung),양경해(Kyung Hae Yang) 한국아동복지학회 2015 한국아동복지학 Vol.- No.50

본 연구의 목적은 일반가정위탁과 친족가정위탁의 양육환경과 아동의 장기적 발달성과 차이를 비교하는 것이다. 특히 시간에 따른 변화 추이에 있어 위탁 유형 간 차이를 분석하고자 하였다. 이를 위해 아동의 가정위탁 배치 시점부터 매년 설문조사를 통해 구축된 가정위탁아동 패널연구 2기 1-4차 데이터를 분석하였다. 연구대상으로 1-4차 조사에 모두 참여하였으며, 4차까지 배치시점과 동일한 위탁유형이면서 친가정복귀를 경험하지 않은 아동 총 77명이 포함되었다. 양육환경과 아동발달에 있어 시간에 따른 종단적 변화 추이를 탐색하고, 이 변화 추이가 위탁유형에 따라 다른지 분석하기 위해 반복측정분산분석(repeated measures ANOVA)을 활용하였다. 분석 결과, 배치 시점에서는 일반위탁아동이 친족위탁아동에 비해 양육환경과 발달 측면 모두에서 불리한 상황에 있었으나 시간에 지남에 따라 긍정적인 방향으로 변화를 보였다. 특히 일반위탁아동이 양육자의 양육태도를 더 긍정적으로 인식하였으며, 위탁가정 배치 이후 학대 피해 수준이 급격히 낮아지는 변화를 보였다. 양육자에 대한 애착과 학교적응에서 두 집단 아동모두 시간에 따라 대체로 긍정적인 변화양상을 보였다. 우울·불안의 경우, 집단 간에도, 시간 변화에 따라서도 유의미한 차이를 보이지 않았다. 공격성은 유의미한 집단 차이를 보이지 않았으나 두 집단 아동 모두 배치 후공격성이 낮아지는 변화를 나타냈다. 정리하면, 일반위탁이 친족위탁에 비해 양육환경이 우수한 것으로 보이며, 발달 측면에서도 일반위탁아동이 시간에 따른 긍정적인 변화 폭이 더 컸다. 그러나 배치시점부터 이미 존재했던 일반위탁과 친족위탁 아동의 발달성과에 있어서 격차가 없어지지는 않았다. 이 결과를 바탕으로 본 연구는 위탁아동의 발달 증진을 돕기 위한 정책적, 실천적 함의를 논하였다. This study aimed to compare the caregiving environments and longitudinal developmental outcomes of children living in either kinship care or non-kinship foster care settings. This study also intended to evaluate whether changes in caregiving environments and developmental outcomes over time in the two groups differed by kinship status. The study participants were drawn from a sample of 「the Panel Study of Korean Foster Care Children」. Using repeated measures ANOVA, data were analyzed on 77 children who participated in the surveys of the first to fourth waves of the panel study, and who experienced neither placement changes nor family reunification. The results showed that children in non-kinship care were at a more disadvantageous status than those in kinship care at baseline in terms of their caregiving environments and developmental outcomes. With respect to caregivng environments, the level of experiences of abuse experiences for children in non-kinship care decreased dramatically after being placed to foster care. With respect to longitudinal developmental outcomes, children in both groups showed positive changes in attachment with caregivers and school adjustment. The analysis revealed that non-kinship care provides better caregiving environments than kinship care. In addition, developmental outcomes improved significantly more in children in non-kinship care over time than in those in kinship care. However, the large gap in developmental outcomes at baseline between the two groups remained nearly unchanged over the follow-up period. Based on the results, policy and practice implications are discussed.

여러 번 가정위탁 양육을 진행한 일반 위탁부모의 경험

강향숙(Kang, Hyangsook),강현아(Kang, Hyunah),정익중(Chung, Ick-Joong),오세현(Oh, Sehyeon) 한국아동복지학회 2021 한국아동복지학 Vol.70 No.2

본 연구는 두 번 이상의 가정위탁 양육을 진행 중인 일반 위탁부모의 경험을 현상학적 질적 연구를 통해 알아보는 것이다. 서로 다른 아동에 대한 두 번 이상의 위탁양육을 경험한 일반 위탁부모 6명을 대상으로 하였다. 2019년 2월부터 2019년 4월까지 3개월에 걸쳐 진행된 심층 인터뷰 결과를 분석하였다. 연구 결과 두 번 이상의 위탁 양육 경험은 〈두 번째를 가능하게 하는 첫 번째〉, 〈백인백색(百人百色)의 아이들〉, 〈가족으로 성장해 가는 화학작용〉의 3개의 주제와 10개의 구성 요소로 범주화 되었다. 이러한 결과를 통해 가정위탁의 활성화를 위한 다양한 방안과 지원의 필요성을 제기하였다. The purpose of this qualitative study was to explore the experience of foster parents who have accepted new foster care placements. For this purpose, in-depth interviews were conducted with six foster parents from February 2019 to April 2019. During the interviews, foster parents shared their experiences of accepting new placements and the meaning of caring for diverse foster children. The data were analyzed using a phenomenological qualitative research method. The results reveal three themes representing the meanings of foster parents’ experiences (‘The first foster caring that makes the second possible’, ‘Every child is unique’, and ‘Growing into a family’) and 10 subthemes. Based on the results, implications and supports for foster care are suggested.

조부모의 학령 초기 손자녀 대리양육 경험에 관한 질적 연구

송승민(Seung-Min Song),이운경(Woon Kyung Lee),이윤형(Yoon Hyung Lee),강현아(Hyunah Kang),김은혜(Eun Hye Kim),강하라(Hyunah Kang) 한국아동학회 2017 아동학회지 Vol.38 No.1

Objective: The present study examined the perspectives of grandparents raising their grandchildren in an attempt to better understand grandparents’ child-rearing experience while providing kinship foster care to their primary-grade grandchildren. Methods: Data were collected through individual in-depth interviews with eight grandparents who have raised one or two primary-grade (ages 8—10) grandchildren using a qualitative approach. Results: First, the participants viewed the reason for their kinship foster care as a failure for caring for their own children and accepted the present grandparent-care provision as their responsibility. Second, the participants communicated constant struggles with their own health and grandchild-care as well as positive/negative emotions associated with the care provision. Third, most of the participants did not fully understand the developmental needs of their primarygrade grandchildren. Fourth, the participants articulated concerns for their primary-grade grandchildrens learning, peer interactions, school adjustment, and extra-curricular activities. Lastly, the participants all agreed on hoping to raise grandchildren with good personality traits as members of a society and to have them fill the gap from the loss of their parents. Conclusion: Although most participants accepted the current circumstances as their obligation, they still noted difficulties in child-care provision. Given the developmental needs of grandchildren and the resource needs of grandparents, proper and continuous intervention approaches should be developed/provided.

Role of Protein O-Mannosyltransferase Pmt5and Pmt6 in the Cell Wall Integrity and Stress Response of Hansenula polymorpha

Hyunah Kim,Hye Yun Moon,Seon Ah Cheon,Dong-jik Lee,Hyun Ah Kang 한국당과학회 2012 한국당과학회 학술대회 Vol.2012 No.1

Protein O-mannosylation is an essential protein modification that is evolutionarily conserved from bacteria to humans, which is initiated by protein O-mannosyltransferases (Pmts). In the endoplasmic reticulum, Pmt proteins catalyze the transfer of mannose residue to Ser/The residues of secretory proteins. The whole genome information of the thermotolerant methylotrophic yeast Hansenula polymorpha reveals the presence of five PMT homologs, HpPMT1, HpPMT2, HpPMT4, HpPMT5 and HpPMT6. Here we characterized H. polymorpha PMT genes, particularly focusing on a PMT1 subfamily gene, HpPMT5, and a PMT2 subfamily gene, HpPMT6. The promoters of all H. polymorpha PMT genes contain an HpHAC1p binding site, in consistent with their induced expression under UPR condition.Although a single deletion of either HpPMT5 or HpPMT6 did not generate any significant defects, the Hppmt1pmt5 and Hppmt1pmt6 double mutants became more susceptible to cell wall disturbing reagents than the Hppmt1 single deletion mutant. Furthermore, the analysis of HpWsc1 and HpMid2, cell surface sensors of cell wall integrity signaling, and H. polymorpha chitinase, an endogenous O-modified glycoprotein, indicated significant decrease in O-mannosylation in the both Hppmt1pmt5 and Hppmt1pmt6 double mutants. All the fully functional epitope-tagged HpPmt proteins were shown to localize at the ER/Golgi membrane, except for the soluble localization of HpPmt6.The co-IP experiments revealed the complex formation between HpPmt1 and HpPmt2, but no interaction between HpPmt5 and HpPmt2 even in the absence of HpPmt1. Whereas, interestingly, phosphorylation of the mitogen-activated protein kinase Mpk1, which resulted in the stimulation of the cell wall integrity pathway, was markedly activated both in Hppmt1 and Hppmt1pmt5 mutant strains,but not in the Hppmt1pmt6 strain compared to wild type under normal condition. Altogether, these results indicate that HpPmt5 and HpPmt6 have redundant functions to significantly compensate the loss of HpPmt1 in protein O-mannosylation that affects cell growth, cell wall integrity, and stress resistance of H. polymorpha.

Effect of Wall Thickness on Thermal Behaviors of RC Walls Under Fire Conditions

Kang, Jiyeon,Yoon, Hyunah,Kim, Woosuk,Kodur, Venkatesh,Shin, Yeongsoo,Kim, Heesun Korea Concrete Institute 2016 International Journal of Concrete Structures and M Vol.10 No.3

The objective of this paper is to investigate the effect of thickness and moisture on temperature distributions of reinforced concrete walls under fire conditions. Toward this goal, the first three wall specimens having different thicknesses are heated for 2 h according to ISO standard heating curve and the temperature distribution through the wall thickness is measured. Since the thermal behavior of the tested walls is influenced by thickness, as well as moisture content, three additional walls are prepared and preheated to reduce moisture content and then tested under fire exposure. The experimental results clearly show the temperatures measured close to the fire exposed surface of the thickest wall with 250 mm thickness is the highest in the temperatures measured at the same location of the thinner wall with 150 mm thickness because of the moisture clog that is formed inside the wall with 250 mm of thickness. This prevents heat being transferred to the opposite side of the heated surface. This is also confirmed by the thermal behavior of the preheated walls, showing that the temperature is well distributed in the preheated walls as compared to that in non-preheated walls. Finite element models including moisture clog zone are generated to simulate fire tests with consideration of moisture clog effect. The temperature distributions of the models predicted from the transient heat analyses are compared with experimental results and show good agreements. In addition, parametric studies are performed with various moisture contents in order to investigate effect of moisture contents on the thermal behaviors of the concrete walls.