• Title/Summary/Keyword: immunoprecipitation

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Phosphorylation of the Nucleocapsid Protein of Bovine Coronavirus Expressed with a Recombinant Baculovirus Vector

  • Yoo, dongwan;Graham-J.Cox
    • Journal of Microbiology and Biotechnology
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    • v.2 no.2
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    • pp.122-128
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    • 1992
  • Post-translational modifications of the nucleocapsid protein of bovine coronavirus (Quebec strain) were investigated. Coronavirions were radiolabelled in vivo with inorganic $[^{32}P]$orthophosphate and analysed by SDS-PAGE, followed by autoradiography. A single polypeptide with a migration rate of 55 KDa was identified by metabolic phosphate labelling, demonstrating that the nucleocapsid protein of bovine coronavirus was a phosphoprotein. A gene encoding the nucleocapsid protein was inserted immediately downstream from the polyhedrin promoter of Autographa californica nuclear polyhedrosis baculovirus. Spodoptera frugiperda cells infected with this recombinant baculovirus synthesized a 55 KDa polypeptide, as demonstrated by immunoprecipitation with anti-nucleocapsid monoclonal antibody. The recombinant nucleocapsid protein synthesized in Spodoptera cells could also be labelled by $[^{32}P]$orthophosphate. Phosphoamino acid analysis showed that both serine and threonine residues were phosphorylated in authentic, as well as in recombinant nucleocapsid proteins, with a relative phosphorylation ratio of 7:3. Our studies demonstrated that the nucleocapsid protein of bovine coronavirus was a serine and threonine-phosphorylated protein and that Spodoptera insect cells were able to properly phosphorylate the relevant foreign proteins.

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High-Resolution Microarrays for Mapping Promoter Binding sites and Copy Number Variation in the Human Genome

  • Albert Thomas
    • Proceedings of the Korean Society for Bioinformatics Conference
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    • 2006.02a
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    • pp.125-126
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    • 2006
  • NimbleGen has developed strategies to use its high-density oligonucleotide microarray platform (385,000 probes per array) to map both promoter binding sites and copy number variation at very high-resolution in the human genome. Here we describe a genome-wide map of active promoters determined by experimentally locating the sites of transcription imitation complex binding throughout the human genome using microarrays combined with chromatin immunoprecipitation. This map defines 10,567 active promoters corresponding to 6,763 known genes and at least 1,196 un-annotated transcriptional units. Microarray-based comparative genomic hybridisation (CGH) is animportant research tool for investigating chromosomal aberrations frequently associated with complex diseases such as cancer, neuropsychiatric disorders, and congenital developmental disorders. NimbleGen array CGH is an ultra-high resolution (0.5-50 Kb) oligo array platform that can be used to detect amplifications and deletions and map the associated breakpoints on the whole-genome level or with custom fine-tiling arrays. For whole-genome array CGH, probes are tiled through genic and intergenic regions with a median probe spacing of 6 Kb, which provides a comprehensive, unbiased analysis of the genome.

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The Physical Interaction between Nucleotide-Binding Oligomerization Domain Containing 2 and Leucine-Rich Repeat Kinase 2

  • Jung, Ji-A;Park, Sangwook
    • Biomedical Science Letters
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    • v.26 no.1
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    • pp.47-50
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    • 2020
  • Recently, decades of robust researches on degenerative brain disorder have been highlighted on the interactive connection of gut and brain. In terms of inflammatory cytokine production, others have shown that Nucleotide-Binding Oligomerization Domain Containing 2 (NOD2) is involved with Leucine-Rich Repeat Kinase 2 (LRRK2). HEK293T cells were transiently co-transfected with Myc-tagged LRRK2 and Flag-tagged NOD2 and then followed by co-immunoprecipitation assay. In this study, we provide the novel finding of physical protein-protein interaction between NOD2 and LRRK2. G2019S variant has shown stronger interactions against NOD2 than those of wild type LRRK2. In an axis of NOD2-LRRK2 communication, it is believed to pave a new way in the understanding of the bidirectional molecular mechanism of brain disorder, including Parkinson's disease into gut inflammatory disease, including Crohn's disease.

Preparation of Dopamine Transporter-specific Antibodies Using Molecular Cloned Genes

  • Lee, Shee-Yong;Im, Suhn-Young;Kim, Kyeong-Man
    • Archives of Pharmacal Research
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    • v.22 no.3
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    • pp.262-266
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    • 1999
  • Dopamine transporter (DAT) plays the most important role in terminating the actions of dopamines released into the synaptic cleft. DAT is also the target of various psychotropic drugs such as cocaine and amphetamine. In this study were prepared DAT-specific antibodies using the 2nd extracellular loop of rat DAT as an antigen. The 2nd extracellular loop of the rat DAT was expressed in bacterial as a fusion protein with glutathione-S-transferase, and injected ito rabbits to raise antibodies. Produced antibodies clearly recognized the rat DAT in ELISA, immunoblotting, and immumoprecipitation. As expected from the high sequence homology between the rat and human DAT, the antibodies raised for the rat DAT cross-reacted with the human DAT in the immunoblotting. Considering the specificity for DAT with wide range of applications such as ELISA, immunoblotting, and immunoprecipitation, these antibodies would be valuable tool for understanding the pharmacological actions of dopamine transporter and drug addition.

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DRG2 Deficiency Causes Impaired Microtubule Dynamics in HeLa Cells

  • Dang, Thao;Jang, Soo Hwa;Back, Sung Hoon;Park, Jeong Woo;Han, In-Seob
    • Molecules and Cells
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    • v.41 no.12
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    • pp.1045-1051
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    • 2018
  • The developmentally regulated GTP binding protein 2 (DRG2) is involved in the control of cell growth and differentiation. Here, we demonstrate that DRG2 regulates microtubule dynamics in HeLa cells. Analysis of live imaging of the plus-ends of microtubules with EB1-EGFP showed that DRG2 deficiency (shDRG2) significantly reduced the growth rate of HeLa cells. Depletion of DRG2 increased 'slow and long-lived' subpopulations, but decreased 'fast and short-lived' subpopulations of microtubules. Microtubule polymerization inhibitor exhibited a reduced response in shDRG2 cells. Using immunoprecipitation, we show that DRG2 interacts with tau, which regulates microtubule polymerization. Collectively, these data demonstrate that DRG2 may aid in affecting microtubule dynamics in HeLa cells.

Identification of Oocyte-Specific Diva-Associated Proteins using Mass Spectrometry (Mass Spectrometry를 이용한 난자 특이적인 Diva와 상호작용하는 단백질의 동정)

  • Yoon, Se-Jin;Kim, Jung-Woong;Choi, Kyung-Hee;Lee, Sook-Hwan;Lee, Kyung-Ah
    • Clinical and Experimental Reproductive Medicine
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    • v.33 no.3
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    • pp.189-198
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    • 2006
  • Objective: We previously described that Diva is highly expressed in matured metaphase II (MII) oocytes compared to immature germinal vesicle (GV) oocytes in mouse. We report here that the expression of Diva transcript as well as protein is oocyte-specific. To elucidate its physiological role in oocyte, the binding partner(s) of Diva has been identified by using immunoprecipitation (IP) followed by Mass Spectrometry. Methods: NIH/3T3 cells were transiently transfected for 24 h with either empty vector for control or FLAG-tagged mouse Diva construct, and IP was performed with anti-FLAG antibody. The immuno-isolated complexes were resolved by SDS-PAGE on a 12% gel followed by Coomassie Blue staining. For in-gel digestion, 15 bands of interest were excised manually and digested with trypsin. All mass spectra were acquired at a positive reflector mode by a 4700 Proteomics Analyzer (Applied Biosystems, Framingham, MA). Proteins were identified by searching the NCBI nonredundant database using MASCOT Peptide Mass Fingerprint software (Matrixscience, London). Results: Diva-associated complexes were formed in FLAG-tagged mouse Diva-overexpressed NIH/3T3 cells via IP using anti-FLAG-conjugated beads. Among the excised 15 bands, actin and actin-binding proteins such as tropomyosin, tropomodulin 3, and ${\alpha}$-actinin were identified. Binding between Diva and actin or tropomyosin was confirmed by IP followed by Western blot analysis. Both bindings were also detected endogenously in mouse ovaries, indicating that Diva works with actin and tropomyosin. Conclusions: This is the first report that immuno-isolated Diva-associated complexes are related to actin filament of the cytoskeletal system. When we consider the association of Diva with actin and tropomyosin, oocyte-specific Diva may play a role in modulating the cytoskeletal system during oocyte maturation.

PD-1 Expression in LPS-Induced Raw264.7 Cells Is Regulated via Co-activation of Transcription Factor NF-κB and IRF-1 (Lipopolysaccharide 유도된 Raw264.7 세포주에서 전사조절인자 NF-κB와 IRF-1의 공동작용에 의해 조절되는 PD-1 발현연구)

  • Choi, Eun-Kyoung;Lee, Soo-Woon;Lee, Soo-Woong
    • Korean Journal of Microbiology
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    • v.49 no.4
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    • pp.301-308
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    • 2013
  • Programmed Death-1 (PD-1) is one of the important immune-inhibitory molecules which was expressed in T cells, B cells, NKT cells, and macrophages activated by various immune activating factors. Lipopolysaccharide (LPS), the major component of the outer membrane of Gram-negative bacteria, is one of the crucial immunogens for PD-1 expression. However, there are only a few reports on the expression mechanisms of PD-1 in innate immune cells. In this study, we investigate the expression mechanisms of PD-1 in LPS-stimulated Raw264.7 cell lines by RT-PCR, Western Blot, flow cytometry as well as ChIP assay and co-immunoprecipitation. When Raw264.7 cells were stimulated with LPS, PD-1 expression was greatly up-regulated via PI3K and p38 signaling. Primary macrophages isolated from LPS-injected mice were also shown the increased expression of PD-1. In promoter assay, NF-${\kappa}B$ and IRF-1 binding regions in mouse PD-1 promoter are important for PD-1 expression. We also found that the co-activation of NF-${\kappa}B$ and IRF-1 is indispensable for the maximum PD-1 expression. These results indicate that the modulation of PD-1 expressed in innate immune cells could be a crucial for the disease therapy such as LPS-induced mouse sepsis model.

Methionyl-tRNA-synthetase is a Novel Interacting Protein of LRRK2 (파킨스병 유전인자인 LRRK2와 상호작용하는 methionyl-tRNA synthetase)

  • Kim, Hyejung;Ho, Dong Hwan;Son, Ilhong;Seol, Wongi
    • Journal of Life Science
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    • v.28 no.2
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    • pp.170-175
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    • 2018
  • Parkinson's disease (PD) is the most common movement disorder and the second most common neurodegenerative disease after Alzheimer's disease. Approximately 5~10% of PD patients are familial PD cases. Leucine-rich repeat kinase 2 (LRRK2) has been known to be a causal gene of PD when it is mutated. LRRK2 contains the functional kinase and GTPase domains as well as leucine-rich repeat (LRR) and WD40 domains that are known to play critical roles for protein-protein interaction, suggesting that LRRK2-interacting proteins are important regulators for PD pathogenesis. In an effort to identify proteins interacting with LRRK2, we carried out co-immunoprecipitation of LRRK2 antibody using extracts of NIH3T3 cells that express LRRK2 at a relatively high level. The mass spectrometry analysis of a precipitated band revealed that the co-precipitated band was methionyl-tRNA synthetase (MRS), an ancient enzyme that transfers methionin to its cognate tRNA. The interaction of MRS with LRRK2 was confirmed again by co-immunoprecipitation of endogenous proteins and GST pull-down assays. However, LRRK2 did not phosphorylate recombinant MRS protein in in vitro kinase assays, and over-expression of LRRK2 or MRS did not affect the stability of its partner protein. Our data indicate that LRRK2 interacts with but does not phosphorylate MRS, and the stability of each partner is not affected by the other.

Protein Arginine Methyltransferase 5 (PRMT5) Regulates Adipogenesis of 3T3L-1 Cells (단백질 아르기닌 메틸전이효소 5(PRMT5)에 의한 3T3L-1 세포의 지방세포 분화 조절)

  • Jang, Min Jung;Yang, Ji Hye;Kim, Eun-Joo
    • Journal of Life Science
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    • v.28 no.7
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    • pp.765-771
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    • 2018
  • Peroxisome proliferator-activated receptor gamma ($PPAR{\gamma}$) is a key transcription factor that regulates adipogenesis, and epigenetic control of $PPAR{\gamma}$ is of great interest in obesity-inhibition research. Our previous study showed that CACUL1 (CDK2-associated cullin domain 1) acts as a corepressor that inhibits $PPAR{\gamma}$ transcriptional activity and adipocyte differentiation. Here, we investigated the roles of protein arginine methyltransferase 5 (PRMT5), a novel binding partner of CACUL1, in regulating $PPAR{\gamma}$. The interaction between PRMT5 and CACUL1 was shown by immunoprecipitation assay in vivo and GST pulldown assay in vitro. As shown by luciferase reporter assay, PRMT5 and CACUL1 cooperated to inhibit the transcriptional activity of $PPAR{\gamma}$. The suppressive role of PRMT5 in adipogenesis was examined by Oil Red O staining using 3T3-L1 cells, which stably overexpress or deplete PRMT5. Overexpression of PRMT5 suppresses $PPAR{\gamma}$-mediated adipogenesis, whereas PRMT5 knockdown increases lipid accumulation in 3T3-L1 cells. Consistently, PRMT5 attenuates the expression of Lpl and aP2, the target genes of $PPAR{\gamma}$, as demonstrated by RT-qPCR analysis. Overall, these results suggest that PRMT5 interacts with CACUL1 to impair the transcriptional activity of $PPAR{\gamma}$, leading to the inhibition of adipocyte differentiation. Therefore, the regulation of PRMT5 enzymatic activity may provide a clue to develop an anti-obesity drug.