• Title/Summary/Keyword: molecular functions

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Crystallization and preliminary X-ray analysis of API5-FGF2 complex

  • Bong, Seoung Min;Lee, Byung Il
    • Biodesign
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    • v.6 no.4
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    • pp.92-95
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    • 2018
  • API5 is a unique oncogenic, non-BIR type IAP nuclear protein and is up-regulated in several cancers. It exerts several functions, such as apoptosis inhibition, cell cycle progression, cancer immune escape, and anticancer drug resistance. Although structural studies of API have revealed that API5 mediates protein-protein interactions, its detailed molecular functions remain unknown. Since FGF2 is one of API5's major interacting proteins, structural studies of the API5-FGF2 complex will provide insight into both proteins' molecular function. We overexpressed and purified API5 and FGF2 in Escherichia coli and crystallized the API-FGF2 complex using polyethylene glycol (PEG) 6000 as a precipitant. Diffraction data were collected to a $2.7{\AA}$ resolution using synchrotron X-rays. Preliminary diffraction analysis revealed that the API5-FGF2 complex crystal belongs to the space group $P2_12_12_1$ with the following unit cell parameters: a = 46.862, b = 76.523, $c=208.161{\AA}$. One asymmetric unit with 49.9% solvent contains one API5-FGF2 complex. Molecular replacement calculation, using API5 and FGF2 coordinates, provided a clear electron density map for an API5-FGF2 complex.

Simulation Methods for Prediction of Membrane Protein Structure

  • Son, Hyeon-S.
    • Proceedings of the Korean Biophysical Society Conference
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    • 1998.06a
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    • pp.10-10
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    • 1998
  • IMPs are important to cells in functions such as transport, energy transduction and signalling. Three dimensional molecular structures of such proteins at atomic level are needed to understand such processes. Prediction of such structures (and functions) is necessary especially because there are only a small number of membrane protein structures determined in atomic resolution.(omitted)

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Identification of Molecular Signatures from Different Vaccine Adjuvants in Chicken by Integrative Analysis of Microarray Data

  • Kim, Duk Kyung;Won, Kyeong Hye;Moon, Seung Hyun;Lee, Hak-Kyo
    • Asian-Australasian Journal of Animal Sciences
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    • v.29 no.7
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    • pp.1044-1051
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    • 2016
  • The present study compared the differential functions of two groups of adjuvants, Montanide incomplete Seppic adjuvant (ISA) series and Quil A, cholesterol, dimethyl dioctadecyl ammonium bromide, and Carbopol (QCDC) formulations, in chicken by analyzing published microarray data associated with each type of vaccine adjuvants. In the biological function analysis for differentially expressed genes altered by two different adjuvant groups, ISA series and QCDC formulations showed differential effects when chickens were immunized with a recombinant immunogenic protein of Eimeria. Among the biological functions, six categories were modified in both adjuvant types. However, with respect to "Response to stimulus", no biological process was modified by the two adjuvant groups at the same time. The QCDC adjuvants showed effects on the biological processes (BPs) including the innate immune response and the immune response to the external stimulus such as toxin and bacterium, while the ISA adjuvants modified the BPs to regulate cell movement and the response to stress. In pathway analysis, ISA adjuvants altered the genes involved in the functions related with cell junctions and the elimination of exogenous and endogenous macromolecules. The analysis in the present study could contribute to the development of precise adjuvants based on molecular signatures related with their immunological functions.

Differential Functions of Ras for Malignant Phenotypic Conversion

  • Moon Aree
    • Archives of Pharmacal Research
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    • v.29 no.2
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    • pp.113-122
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    • 2006
  • Among the effector molecules connected with the group of cell surface receptors, Ras proteins have essential roles in transducing extracellular signals to diverse intracellular events, by controlling the activities of multiple signaling pathways. For over 20 years since the discovery of Ras proteins, an enormous amount of knowledge has been accumulated as to how the proteins function in overlapping or distinct fashions. The signaling networks they regulate are very complex due to their multiple functions and cross-talks. Much attention has been paid to the pathological role of Ras in tumorigenesis. In particular, human tumors very frequently express Ras proteins constitutively activated by point mutations. Up to date, three members of the Ras family have been identified, namely H-Ras, K-Ras (A and B), and N-Ras. Although these Ras isoforms function in similar ways, many evidences also support the distinct molecular function of each Ras protein. This review summarizes differential functions of Ras and highlights the current view of the distinct signaling network regulated by each Ras for its contribution to the malignant phenotypic conversion of breast epithelial cells. Four issues are addressed in this review: (1) Ras proteins, (2) membrane localization of Ras, (3) effector molecules downstream of Ras, (4) Ras signaling in invasion. In spite of the accumulation of information on the differential functions of Ras, much more remains to be elucidated to understand the Ras-mediated molecular events of malignant phenotypic conversion of cells in a greater detail.

Molecular Dynamics Simulation Studies of Zeolite A. Ⅵ. Vibrational Motion of Non-Rigid Zeolite-A Framework

  • 이송희;최상구
    • Bulletin of the Korean Chemical Society
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    • v.19 no.4
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    • pp.422-428
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    • 1998
  • In the present paper, we report a molecular dynamics (MD) simulation of non-rigid zeolite-A framework only as the base case for a consistent study of the role of intraframework interaction on several zeolite-A systems using the same technique in our previous studies of rigid zeolite-A frameworks. Usual bond stretching, bond angle bending, torsional rotational, and non-bonded Lennard-Jones and electrostatic interactions are considered as intraframework interaction potentials. The comparison of experimental and calculated structural parameters confirms the validity of our MD simulation for zeolite-A framework. The radial distribution functions of non-rigid zeolite-A framework atoms characterize the vibrational motion of the framework atoms. Mean square displacements are all periodic with a short period of 0.08 ps and a slow change in the amplitude of the vibration with a long period of 0.53 ps. The displacement auto-correlation (DAC) and neighbor-correlation (DNC) functions describe the up-and-down motion of the framework atoms from the center of α-cage and the back-and-forth motion on each ring window from the center of each window. The DAC and DNC functions of the framework atoms from the center of α-cage at the 8-ring windows have the same period of the up-and-down motion, but those functions from the center of 8-ring window at the 8-ring windows are of different periods of the back-and-forth motion.

Expression, subcellular localization, and antioxidant role of mammalian methionine sulfoxide reductases in Saccharomyces cerevisiae

  • Kwak, Geun-Hee;Kim, Jae-Ryong;Kim, Hwa-Young
    • BMB Reports
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    • v.42 no.2
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    • pp.113-118
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    • 2009
  • Despite the growing body of evidence suggesting a role for MsrA in antioxidant defense, little is currently known regarding the function of MsrB in cellular protection against oxidative stress. In this study, we overexpressed the mammalian MsrB and MsrA genes in Saccharomyces cerevisiae and assessed their subcellular localization and antioxidant functions. We found that the mitochondrial MsrB3 protein (MsrB3B) was localized to the cytosol, but not to the mitochondria, of the yeast cells. The mitochondrial MsrB2 protein was detected in the mitochondria and, to a lesser extent, the cytosol of the yeast cells. In this study, we report the first evidence that MsrB3 overexpression in yeast cells protected them against $H_2O_2$-mediated cell death. Additionally, MsrB2 overexpression also provided yeast cells with resistance to oxidative stress, as did MsrA overexpression. Our results show that mammalian MsrB and MsrA proteins perform crucial functions in protection against oxidative stress in lower eukaryotic yeast cells.

Structural and Functional Insight into Proliferating Cell Nuclear Antigen

  • Park, So Young;Jeong, Mi Suk;Han, Chang Woo;Yu, Hak Sun;Jang, Se Bok
    • Journal of Microbiology and Biotechnology
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    • v.26 no.4
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    • pp.637-647
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    • 2016
  • Proliferating cell nuclear antigen (PCNA) is a critical eukaryotic replication accessory factor that supports DNA binding in DNA processing, such as DNA replication, repair, and recombination. PCNA consists of three toroidal-shaped monomers that encircle double-stranded DNA. The diverse functions of PCNA may be regulated by its interactions with partner proteins. Many of the PCNA partner proteins generally have a conserved PCNA-interacting peptide (PIP) motif, located at the N- or C- terminal region. The PIP motif forms a 310 helix that enters into the hydrophobic groove produced by an interdomain-connecting loop, a central loop, and a C-terminal tail in the PCNA. Post-translational modification of PCNA also plays a critical role in regulation of its function and binding partner proteins. Structural and biochemical studies of PCNA-protein will be useful in designing therapeutic agents, as well as estimating the outcome of anticancer drug development. This review summarizes the characterization of eukaryotic PCNA in relation to the protein structures, functions, and modifications, and interaction with proteins.

Molecular genetic decoding of malformations of cortical development

  • Lim, Jae Seok;Lee, Jeong Ho
    • Journal of Genetic Medicine
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    • v.12 no.1
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    • pp.12-18
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    • 2015
  • Malformations of cortical development (MCD) cover a broad spectrum of developmental disorders which cause the various clinical manifestations including epilepsy, developmental delay, and intellectual disability. MCD have been clinically classified based on the disruption of developmental processes such as proliferation, migration, and organization. Molecular genetic studies of MCD have improved our understanding of these disorders at a molecular level beyond the clinical classification. These recent advances are resulted from the development of massive parallel sequencing technology, also known as next-generation sequencing (NGS), which has allowed researchers to uncover novel molecular genetic pathways associated with inherited or de novo mutations. Although an increasing number of disease-related genes or genetic variations have been identified, genotype-phenotype correlation is hampered when the biological or pathological functions of identified genetic variations are not fully understood. To elucidate the causality of genetic variations, in vivo disease models that reflect these variations are required. In the current review, we review the use of NGS technology to identify genes involved in MCD, and discuss how the functions of these identified genes can be validated through in vivo disease modeling.