• Molecules and Cells
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• 제40권12호
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• pp.925-934
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• 2017

The Cdc6 protein is essential for the initiation of chromosomal replication and functions as a licensing factor to maintain chromosome integrity. During the S and G2 phases of the cell cycle, Cdc6 has been found to inhibit the recruitment of pericentriolar material (PCM) proteins to the centrosome and to suppress centrosome over-duplication. In this report, we analyzed the correlation between these two functions of Cdc6 at the centrosome. Cdc6 depletion increased the population of cells showing centrosome over-duplication and premature centrosome separation; Cdc6 expression reversed these changes. Deletion and fusion experiments revealed that the 18 amino acid residues (197-214) of Cdc6, which were fused to the Cdc6-centrosomal localization signal, suppressed centrosome over-duplication and premature centrosome separation. Cdc6 mutant proteins that showed defective ATP binding or hydrolysis did not exhibit a significant difference in suppressing centrosome over-duplication, compared to the wild type protein. In contrast to the Cdc6-mediated inhibition of PCM protein recruitment to the centrosome, the independence of Cdc6 on its ATPase activity for suppressing centrosome over-duplication, along with the difference between the Cdc6 protein regions participating in the two functions, suggested that Cdc6 controls centrosome duplication in a manner independent of its recruitment of PCM proteins to the centrosome.

• 한국자기공명학회논문지
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• 제22권1호
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• pp.18-25
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• 2018

Replication protein A (RPA) is an essential single-stranded DNA binding protein in DNA processing. It is known that N terminal domain of RPA70 (RPA70N) recruits various protein partners including damage-response proteins such as p53, ATRIP, Rad9, and MRE11. Although the common binding residues of RPA70N were revealed, dynamic properties of the protein are not studied yet. In this study, we measured $^{15}N$ relaxation parameters ($T_1,\;T_2$ and heteronuclear NOE) of human RPA70N and analyzed them using model-free analysis. Our data showed that the two loops near the binding site experience fast time scale motion while the binding site does not. It suggests that the protein binding surface of RPA70N is mostly rigid for minimizing entropy cost of binding and the loops can experience conformational changes.

• Bulletin of the Korean Chemical Society
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• 제27권11호
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• pp.1731-1732
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• 2006

• 생명과학회지
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• 제26권10호
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• pp.1182-1188
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• 2016

Membrane associated guanylate kinase inverted-3 (MAGI-3)는 세포-세포 연접의 형성을 유도하는 막단백질인 membrane associated guanylate kinases (MAGUKs)의 한 종류 단백질로 140 kDa 크기를 가진다. MAGI-3는 PTEN/MMAC와 함께 협력하여 AKT/PKB의 kinase 활성을 조절하거나 MAPKs 신호전달경로로 ERK 활성을 조절로 한다. Coxsackievirus B3 (CVB3)는 가장 일반적으로 감염된 심근 세포 사멸으로 인한 바이러스성 심근염을 일으키는 enterovirus에 속하는 인간 병원체이다. 이전 연구에서 protein kinase B (PKB, 또는 AKT)와 extracellular signal-regulated kinases 1/2 (ERK1/2)의 활성은 HeLa 세포에서 CVB3 복제를 위해 필수적임이 밝혀졌다. 본 연구에서 enterovirus 복제와 AKT 신호 활성조절에서 MAGI-3의 역할을 검증하였다. MAGI-3-Flag의 발현은 CVB3 감염 후에 AKT 신호 활성과 viral capsid protein VP1의 발현을 유도하였으며 이는 MAGI-3에 의한 enterovirus 증식 조절을 보여주었다. AKT 신호는 MAGI-3 발현에 의해 enterovirus 감염과 함께 유의하게 증가하고 이것은 감염 바이러스의 증식을 활발하게 유도함을 확인하였다. 이 결과는 MAGI-3의 발현은 AKT와 ERK의 활성이 증가하고, 더 나아가 바이러스 증식과 연관이 있다는 것을 입증한다. MAGI-3는 아마도 AKT 신호 조절을 통해 enterovirus 증식 조절에 중요한 역할을 할 것으로 생각된다.

• The Plant Pathology Journal
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• 제33권3호
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• pp.213-228
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• 2017

Plasmodesmata (PDs) are specialized intercellular channels that facilitate the exchange of various molecules, including sugars, ribonucleoprotein complexes, transcription factors, and mRNA. Their diameters, estimated to be 2.5 nm in the neck region, are too small to transfer viruses or viral genomes. Tobacco mosaic virus and Potexviruses are the most extensively studied viruses. In viruses, the movement protein (MP) is responsible for the PD gating that allows the intercellular movement of viral genomes. Various host factors interact with MP to regulate complicated mechanisms related to PD gating. Virus replication and assembly occur in viral replication complex (VRC) with membrane association, especially in the endoplasmic reticulum. VRC have a highly organized structure and are highly regulated by interactions among the various host factors, proteins encoded by the viral genome, and the viral genome. Virus trafficking requires host machineries, such as the cytoskeleton and the secretory systems. MP facilitates the virus replication and movement process. Despite the current level of understanding of virus movement, there are still many unknown and complex interactions between virus replication and virus movement. While numerous studies have been conducted to understand plant viruses with regards to cell-to-cell movement and replication, there are still many knowledge gaps. To study these interactions, adequate research tools must be used such as molecular, and biochemical techniques. Without such tools, virologists will not be able to gain an accurate or detailed understanding of the virus infection process.

• Applied Biological Chemistry
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• 제48권4호
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• pp.301-310
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• 2005

구제역(Foot-and-Mouth Disease: FMD)이란 소, 돼지, 양, 염소 등의 cloven-hoofed 동물에서 나타나는 바이러스성 질병으로 입, 코, 유두, 발굽 등에 수포가 형성되는 것이 특징이다. 일곱 가지 혈청형(O, A, C, Asia1, SAT1, SAT2 and SAT3)으로 분류되는 구제역바이러스(Foot-and-Mouth Disease Virus: FMDV)는 single stranded positive RNA virus로 nonenveloped capsid virus이다. Viral genome은 8.2 Kb로 하나의 ORF인 polyprotein으로 되어있으며, 크게 capsid protein coding region인 P1, replication related protein coding region인 P2, RNA dependent RNA polymerase coding region인 P3로 구성된다. FMDV는 respiratory tract의 pharynx epithelial cell에 감염되며, lung epithelial cell에서 replication을 한다. 구제역바이러스는 감염율은 높지만 낮은 치사율을 가진다. 2002년 한국에서 구제역이 발병하여 많은 경제적 손실을 입었다. FMDV의 감염을 조절할 수 있는 조절방법이 없는 실정이며, 현재 많은 나라에서는 구제역바이러스의 감염을 막을 수 있는 효과적인 방법을 연구하고 있다. 본 보고서에서는 FMD에 대한 보다 효과적인 예방법인 DNA vaccine, edible vaccine, peptide vaccine에 대해 고찰하였다.

• 한국수산과학회지
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• 제28권2호
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• pp.209-218
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• 1995

본 연구에서는 유전자 복제기작을 생화학적, 분자생물학적 방법을 사용하여 bacteriphage T7을 대상으로 연구하였다. Bacteriophage T7의 유전자 복제, 재조합, 수선시 필수 단백질로 작용하는 gene 2.5 단백질의 생체내 기능에 대한 유전학적 연구와 단백질을 분리 정제하여 복제 단백질들과의 상호작용에 대한 연구를 수행하였다. 연구결과 gene 2.5 단백질은 DNA복제시 필수 구성단백질로 작용하며, 복제과정에서 유전자 복제에 관여하는 핵심 단백질들인 DNA polymerase, helicase/primase와 직접 단백질-단백질 상호 협동 작용을 하는 r것을 증명하였다. 특히 gene 2.5 단백질의 C-terminal domain이 절편된 변이체의 경우 복제 단백질들과 상호작용이 결여되었다. 따라서 C-terminal domain이 gene 2.5 단백질의 기능에 필수적으로 관여함을 입증하였다.

• 한국미생물학회:학술대회논문집
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• 한국미생물학회 2000년도 추계학술발표대회
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• pp.66-77
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• 2000

For a variety of viruses, the primary virus infection has been shown to prevent superinfection with a homologous secondary virus; however, the mechanism of exclusion has not been clearly understood. In this work, we demonstrated that BVDV -infected MDBK cells were protected from superinfection with a homologous superinfecting BVDV, one of the positive-sense RNA pestiviruses, but not with an unrelated rhabdovirus, such as vesicular stomatitis virus. Once superinfection exclusion was established by a primary infection with BVDV, the transfected infectious BVD viral RNA genome was shown to be competent for viral translation, but not viral replication. In addition, our results also demonstrated that upon superinfection, the. viral RNA genome of viral particles was not transferred into the cytoplasm of BVDV -infected cells. Using newly developed system involving rapid generation of the MDBK cells expressing BVD viral proteins, we subsequently found that expression of the viral structural proteins was dispensable for the block occurring at the level of viral RNA replication, but required for the exclusion at the level of viral entry step. Altogether, these findings provide evidence that the superinfection exclusion of BVDV occurs not only at the level of viral replication in which the viral replicase are involved, but also at the level of viral entry with which the viral structural proteins are associated, and that a cellular factor(s) play an essential role in this process.

• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 1993년도 제2회 신약개발 연구발표회 초록집
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• pp.92-92
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• 1993

Point mutations in a highly conserved central region of the HIV-1 integrase protein were analyzed for their effects on viral replication and virion morphogenesis. Conservative amino acid replacements of two amino acid residues invariant un retroviral integrases, D116 and E152 of HIV-1, as well as the highly conserved amino acid S147, completely blocked viral replication in two CD4$\^$＋/ human T cell lines. Mutation of four other highly conserved amino acids in the region had no detectable effect on viral replication, while Mutations at two positions, N117 and Y143, resulted in viruses with a delayed replication phenotype. Characteristic and reproducible defects id virion core structure were observed by electron microscopic analysis of sore of the replication defective integrase point mutants, indicating that mutant integrase proteins can interfere with the process of virion core maturation.

• Journal of Microbiology and Biotechnology
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• 제17권11호
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• pp.1841-1847
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• 2007

We previously identified the origin of replication of p703/5, a small cryptic plasmid from the KBL703 strain of Enterococcus faecalis. The origin of replication contains putative regulatory cis-elements required for replication and a replication initiator (RepA) gene. The replicon of p703/5 is similar in its structural organization to theta-type plasmids, and RepA is homologous to a family of Rep proteins identified in several plasmids from Gram-positive bacteria. Here, we report molecular interactions between RepA and the replication origin of p703/5. DNase I footprinting using recombinant RepA together with electrophoretic mobility shift assays confirmed the binding of RepA to the replication origin of p703/5 via iterons and an inverted repeat. We also demonstrated the formation of RepA dimers and the different binding of RepA to the iteron and the inverted repeat using gel filtration chromatographic analysis, a chemical crosslinking assay, and electrophoretic mobility shift assays in the presence of guanidine hydrochloride. Our results suggest that RepA plays a regulatory role in the replication of the enterococcal plasmid p703/5 via mechanisms similar to those of typical iteroncarrying theta-type plasmids.