Intracellular delivery of recombinant proteins via gold nanoparticle– DNA aptamer composites is independent of the protein physicochemical properties and cell type

염지현,주민주,이보은,Keun P. Kim,하남철,박윤경,배지현,이강석 한국공업화학회 2017 Journal of Industrial and Engineering Chemistry Vol.45 No.-

Here, we report that the gold nanoparticle–DNA aptamer (AuNP–Apt) conjugate-based system canefficiently deliver recombinant proteins into mammalian cells in a manner independent of their size,isoelectric point, and cellular localization. Additionally, AuNP–Apt system-assisted protein delivery canbe effective on primary and stem cells, indicating that its use is not limited to fast-dividing cells. Wefurther show that the intravenously administered AuNP–Apt system can deliver proteins into rat organs. Ourfindings show that this system can serve as a simple, efficient, and versatile platform for the deliveryof recombinant proteins into mammalian living systems.

RraAS2 requires both scaffold domains of RNase ES for high-affinity binding and inhibitory action on the ribonucleolytic activity

허지훈,김대영,주민주,이보은,서소진,이재진,송새미,염지현,하남출,이강석 한국미생물학회 2016 The journal of microbiology Vol.54 No.10

RraA is a protein inhibitor of RNase E (Rne), which catalyzes the endoribonucleolytic cleavage of a large proportion of RNAs in Escherichia coli. The antibiotic‐producing bacterium Streptomyces coelicolor also contains homologs of RNase E and RraA, designated as RNase ES (Rns), RraAS1, and RraAS2, respectively. Here, we report that RraAS2 requires both scaffold domains of RNase ES for high-affinity binding and inhibitory action on the ribonucleolytic activity. Analyses of the steady-state level of RNase E substrates indicated that coexpression of RraAS2 in E. coli cells overproducing Rns effectively inhibits the ribonucleolytic activity of full-length RNase ES, but its inhibitory effects were moderate or undetectable on other truncated forms of Rns, in which the N- or/and C-terminal scaffold domain was deleted. In addition, RraAS2 more efficiently inhibited the in vitro ribonucleolytic activity of RNase ES than that of a truncated form containing the catalytic domain only. Coimmunoprecipitation and in vivo cross-linking experiments further showed necessity of both scaffold domains of RNase ES for high-affinity binding of RraAS2 to the enzyme, resulting in decreased RNA-binding capacity of RNase ES. Our results indicate that RraAS2 is a protein inhibitor of RNase ES and provide clues to how this inhibitor affects the ribonucleolytic activity of RNase ES.

Transcript-specific selective translation by specialized ribosomes bearing genome-encoded heterogeneous rRNAs in V. vulnificus CMCP6

Choi Younkyung,주민주,송우석,Lee Minho,Hyeon Hana,김현리,Yeom Ji-Hyun,Lee Kangseok,Shin Eunkyoung 한국미생물학회 2022 The journal of microbiology Vol.60 No.12

Ribosomes composed of genome-encoded heterogeneous rRNAs are implicated in the rapid adaptation of bacterial cells to environmental changes. A previous study showed that ribosomes bearing the most heterogeneous rRNAs expressed from the rrnI operon (I-ribosomes) are implicated in the preferential translation of a subset of mRNAs, including hspA and tpiA, in Vibrio vulnificus CMCP6. In this study, we show that HspA nascent peptides were predominantly bound to I-ribosomes. Specifically, I-ribosomes were enriched more than two-fold in ribosomes that were pulled down by immunoprecipitation of HspA peptides compared with the proportion of I-ribosomes in crude ribosomes and ribosomes pulled down by immunoprecipitation of RNA polymerase subunit ß peptides in the wild-type (WT) and rrnI-completed strains. Other methods that utilized the incorporation of an affinity tag in 23S rRNA or chimeric rRNA tethering 16S and 23S rRNAs, which generated specialized functional ribosomes in Escherichia coli, did not result in functional I-ribosomes in V. vulnificus CMCP6. This study provides direct evidence of the preferential translation of hspA mRNA by I-ribosomes.

Proton Conducting Membrane based on Crosslinked Sulfonated Polyimide for Direct Methanol Fuel Cell

성경아,김완근,오근환,주민주,박정기 한국전기화학회 2009 한국전기화학회지 Vol.12 No.3

Crosslinked membrane based on sulfonated polyimide was prepared by the introduction of crosslinkable monomer in polymerization process and crosslinking during membrane casting. Crosslinked membranes showed different properties from non-crosslinked membranes. Crosslinking decreased methanol crossover and therefore unit cell using crosslinked membrane showed increased open circuit voltage, 0.81 V, in comparison with unit cell using noncrosslinked membrane, 0.71 V. In addition, water uptake of crosslinked membrane, 40.5%, was lower than that of non-crosslinked membrane, 57.0%, and this resulted in improved dimensional stability. However, proton conductivity of crosslinked membranes showed rather low relative to non-crosslinked membrane due to reduced water uptake.

독자성과 융화성: 인간 실존의 근원적인 두 차원

김윤영,박선웅,이예은,주민주,박유빈 한국심리학회 2016 한국심리학회지 일반 Vol.35 No.2

A considerable amount of attention has been paid to the concepts of agency and communion over the past few decades overseas, as reflected in three special issues in academic journals. However, these concepts are barely introduced to the psychology literature in Korea. In the present article, we presented an organized overview of the so-called "Big Two" which has triggered research on various topics across different fields of studies. First, we introduced different measurements to assess agency and communion. We then explained how these two are related to mental health, physical health, and social relationships. In doing so, we organized studies depending on whether they included the concept of unmitigation. Next, we reviewed narrative studies and how agency and communion themes in narratives are related to psychological well-being. We also detailed the dual perspective model of agency and communion, an approach based on social cognition research. This model uses the two concepts to explain the actor-observer discrepancy in social interactions. Finally, we summarized studies done in Korea about agency and communion, and discussed the future directions of research. 독자성과 융화성은 최근 10년 동안 3개의 학술지에서 관련 특집호가 출간되는 등 해외에서는 많은 관심을 받고 있는 주제이나, 국내에서는 그 개념조차 제대로 소개가 되지 않은 실정이다. 본 논문에서는 Big Two라 불리며 다양한 주제의 연구를 양산해 온 이 두 개념에 관련된 연구를 체계적으로 개관하였다. 먼저, 독자성과 융화성이 어떤 도구를 이용하여 측정되었는지 소개하였다. 다음으로, 독자성과 융화성이 정신 및 신체적 건강, 사회적 관계와 어떤 관련이 있는지 경직성이라는 개념이 포함된 연구와 포함되지 않은 연구를 구분하여 정리하였다. 또 독자성과 융화성 연구의 또 다른 형태인 내러티브 연구에 대한 설명과 관련 연구 결과들을 살펴보았다. 특히, 내러티브 연구는 독자성과 융화성 간의 통합이 사람들의 심리적 발달에 영향을 미친다는 점을 시사하고 있다. 최근에는 독자성과 융화성을 개인차 변인이 아닌 사회인지적 측면에서 접근하는 이중관점 모델이 대두되었는데, 이는 사회적 정보처리의 모든 과정에서 나타나는 행위자와 관찰자 사이의 관점 차이를 독자성과 융화성 개념과 연결 지어 설명한 것으로서 본 논문에서는 이에 대한 설명과 관련 연구들도 함께 개관하였다. 마지막으로, 독자성과 융화성에 관한 국내 연구 현황을 요약하고, 향후 연구 과제에 대해 논의하였다.

RraAS1 inhibits the ribonucleolytic activity of RNase ES by interacting with its catalytic domain in Streptomyces coelicolor

서소진,김대영,송우석,허지훈,주민주,임예리,염지현,이강석 한국미생물학회 2017 The journal of microbiology Vol.55 No.1

RraA is a protein inhibitor of RNase E, which degrades and processes numerous RNAs in Escherichia coli. Streptomyces coelicolor also contains homologs of RNase E and RraA, RNase ES and RraAS1/RraAS2, respectively. Here, we report that, unlike other RraA homologs, RraAS1 directly interacts with the catalytic domain of RNase ES to exert its inhibitory effect. We further show that rraAS1 gene deletion in S. coelicolor results in a higher growth rate and increased production of actinorhodin and undecylprodigiosin, compared with the wild-type strain, suggesting that RraAS1-mediated regulation of RNase ES activity contributes to modulating the cellular physiology of S. coelicolor.

Accuracy and bias in self-perception of performance: Narcissism matters in Korea as well

박선웅,Stefanie M. Tignor,주민주 한국사회과학협의회 2016 Korean Social Science Journal Vol.43 No.2

Debates regarding the nature of self-enhancement versus accurate self-assessment have been active among psychologists for decades. More recently, researchers have become interested in the panculturality of self-enhancement. Some researchers argue that self-enhancement is universal and present within all cultures. Others declare self-enhancement to be a Western tendency, with self-diminishment being the norm among East Asians. Importantly, the majority of such studies have not compared self-perceptions against objective external criteria, especially those with East Asians. Furthermore, the link between narcissism and self-enhancement has been largely overlooked within Korean samples. To address such gaps, we utilized scores on an objective test as a criterion to investigate the accuracy of Koreans’ self-assessments of performance, as well as how individual differences in narcissism are related to such assessments. A sample of Korean students (N = 146; 71 women) completed self-report measures of narcissism and self-esteem, and took a listening comprehension quiz. Estimated and actual scores were collected and used to compute self-enhancement scores. Results demonstrated that Koreans’ self-perceptions of performance on the quiz were quite accurate. As has been found in Western cultures, narcissism was related to self-enhancement.

The α-Barrel Tip Region of Escherichia coli TolC Homologs of Vibrio vulnificus Interacts with the MacA Protein to Form the Functional Macrolide-Specific Efflux Pump MacAB-TolC

이민호,김현리,송새미,주민주,이승화,김대영,한윤수,하남출,이강석 한국미생물학회 2013 The journal of microbiology Vol.51 No.2

TolC and its homologous family of proteins are outer membrane factors that are essential for exporting small molecules and toxins across the outer membrane in Gram-negative bacteria. Two open reading frames in the Vibrio vulnificus genome that encode proteins homologous to Escherichia coli TolC, designated TolCV1 and TolCV2, have 51.3% and 29.6%amino acid identity to TolC, respectively. In this study, we show that TolCV1 and TolCV2 functionally and physically interacted with the membrane fusion protein, MacA, a component of the macrolide-specific MacAB-TolC pump of E. coli. We further show that the conserved residues located at the aperture tip region of the α-hairpin of TolCV1 and TolCV2played an essential role in the formation of the functional MacAB-TolC pump using site-directed mutational analyses. Our findings suggest that these outer membrane factors have conserved tip-to-tip interaction with the MacA membrane fusion protein for action of the drug efflux pump in Gramnegative bacteria.

Rediscovery of antimicrobial peptides as therapeutic agents

Minkyung Ryu,Jaeyeong Park,Ji-Hyun Yeom,주민주,Kangseok Lee 한국미생물학회 2021 The journal of microbiology Vol.59 No.2

In recent years, the occurrence of antibiotic-resistant pathogens is increasing rapidly. There is growing concern as the development of antibiotics is slower than the increase in the resistance of pathogenic bacteria. Antimicrobial peptides (AMPs) are promising alternatives to antibiotics. Despite their name, which implies their antimicrobial activity, AMPs have recently been rediscovered as compounds having antifungal, antiviral, anticancer, antioxidant, and insecticidal effects. Moreover, many AMPs are relatively safe from toxic side effects and the generation of resistant microorganisms due to their target specificity and complexity of the mechanisms underlying their action. In this review, we summarize the history, classification, and mechanisms of action of AMPs, and provide descriptions of AMPs undergoing clinical trials. We also discuss the obstacles associated with the development of AMPs as therapeutic agents and recent strategies formulated to circumvent these obstacles.

Gold nanoparticle-DNA aptamer-assisted delivery of antimicrobial peptide effectively inhibits Acinetobacter baumannii infection in mice

Park Jaeyeong,Shin Eunkyoung,Yeom Ji-Hyun,Choi Younkyung,주민주,이민호,Kim Je Hyeong,Bae Jeehyeon,Lee Kangseok 한국미생물학회 2022 The journal of microbiology Vol.60 No.1

Acinetobacter baumannii causes multidrug resistance, leading to fatal infections in humans. In this study, we showed that Lys AB2 P3-His–a hexahistidine-tagged form of an antimicrobial peptide (AMP) loaded onto DNA aptamer-functionalized gold nanoparticles (AuNP-Apt)–can effectively inhibit A. baumannii infection in mice. When A. baumannii-infected mice were intraperitoneally injected with AuNP-Apt loaded with Lys AB2 P3-His, a marked reduction in A. baumannii colonization was observed in the mouse organs, leading to prominently increased survival time and rate of the mice compared to those of the control mice treated with AuNP-Apt or Lys AB2 P3-His only. This study shows that AMPs loaded onto AuNP-Apt could be an effective therapeutic tool against infections caused by multidrug-resistant pathogenic bacteria in humans.