9 results on '"Tanjing Song"'
Search Results
2. Transcription factor YY1 promotes adipogenesis via inhibiting CHOP-10 expression
- Author
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Qi Qun Tang, Hai Yan Huang, Chun Gu Ma, Tanjing Song, Xi Li, Mei Liu, and Qun He
- Subjects
Serum ,Leucine zipper ,medicine.medical_treatment ,Biophysics ,Biology ,Biochemistry ,Mice ,chemistry.chemical_compound ,Transactivation ,3T3-L1 Cells ,Adipocyte ,medicine ,Animals ,Insulin-Like Growth Factor I ,RNA, Small Interfering ,Promoter Regions, Genetic ,Molecular Biology ,Transcription factor ,YY1 Transcription Factor ,Regulation of gene expression ,ATF3 ,Adipogenesis ,Growth factor ,Cell Biology ,Cell biology ,Gene Expression Regulation ,chemistry ,embryonic structures ,Cancer research ,Cattle ,biological phenomena, cell phenomena, and immunity ,Transcription Factor CHOP - Abstract
CHOP-10, a dominant-negative member of the C/EBP family of transcription factors, is initially expressed by growth-arrested preadipocytes and sequesters/inactivates C/EBPbeta through heterodimerization with its leucine zipper during 3T3-L1 preadipocyte differentiation. Our previous studies indicated that, FBS leads to the down-regulation of CHOP-10 expression after induction, and releasing C/EBPbeta from inhibitory constraint, allowing the transactivation of C/EBPalpha and PPARgamma genes, transcription factors required for terminal adipocyte differentiation. In the present study, we reported that FBS induced the expression of YY1, which bound to CHOP-10 promoter via two adjacent YY1-binding sites, suppressing its expression. The knock-down of YY1 expression with YY1 siRNA increased the expression of CHOP-10, inhibiting adipocyte differentiation. IGF-1, a growth factor present in greater concentration in FBS, independently induced the expression of YY1, and contributed to the down-regulation of CHOP-10 during the adipocyte differentiation program. Our studies suggested that YY1 can be a new adipocyte differentiation stimulator.
- Published
- 2008
3. Functional expression of the globular domain of human adiponectin in Pichia pastoris
- Author
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De Guo Liu, Qi Qun Tang, Hai Yan Huang, Tanjing Song, Xi Li, and Hong Lei Liu
- Subjects
Blood Glucose ,Genetic Vectors ,Immunoblotting ,Molecular Sequence Data ,Biophysics ,White adipose tissue ,Biochemistry ,Pichia ,Cell Line ,Diabetes Mellitus, Experimental ,Pichia pastoris ,law.invention ,Myoblasts ,Mice ,Transformation, Genetic ,Plasmid ,law ,Sequence Homology, Nucleic Acid ,Animals ,Humans ,Amino Acid Sequence ,Phosphorylation ,Codon ,Molecular Biology ,chemistry.chemical_classification ,Binding Sites ,Expression vector ,Base Sequence ,Dose-Response Relationship, Drug ,Adiponectin ,biology ,Fatty Acids ,Fatty acid ,Cell Biology ,biology.organism_classification ,Molecular biology ,Recombinant Proteins ,Yeast ,Diabetes Mellitus, Type 1 ,chemistry ,Recombinant DNA ,Acetyl-CoA Carboxylase - Abstract
Adiponectin is an adipokine that predominantly synthesized and secreted from adipocytes mainly in the white adipose tissue. Here, we report that we have successfully expressed human gAdiponectin (the globular domain of adiponectin) in the methylotrophic yeast Pichia pastoris after codon optimization and established the purification procedure. The human gAdiponectin gene was designed and synthesized by PCR according to the P. pastoris preferred codons, and then inserted into the P. pastoris pPIC9K expression vector. The plasmid was electroporated into the P. pastoris strain GS115 and only the G418 resistance colonies could produce the gAdiponectin. After fermentation and purification, we could get 1.2g of recombinant gAdiponectin (purity is approximately 95%) from a 24 L culture media. The recombinant gAdiponectin is fully functional as evidenced by induction the phosphorylation of ACC in differentiated C2C12 myotubes, significantly lowering the blood glucose level and accelerating the clearance of free fatty acid in animal models.
- Published
- 2007
4. Lactacystin inhibits 3T3-L1 adipocyte differentiation through induction of CHOP-10 expression
- Author
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Qi Qun Tang, Hou Yan Song, Chun Gu Ma, Lin Jiang, Hong Lei Liu, Hai Yan Huang, Tanjing Song, De Guo Liu, Qun He, Jie Gen Chen, Xi Li, and Duan Ma
- Subjects
Lactacystin ,Biophysics ,Mitosis ,Peroxisome proliferator-activated receptor ,Biology ,Biochemistry ,Mice ,chemistry.chemical_compound ,Downregulation and upregulation ,Transcription (biology) ,3T3-L1 Cells ,Adipocyte ,Adipocytes ,medicine ,Animals ,Receptor ,Molecular Biology ,chemistry.chemical_classification ,CCAAT-Enhancer-Binding Protein-beta ,Cyclin-Dependent Kinase 2 ,Cell Differentiation ,DNA ,Cell Biology ,Phenotype ,Molecular biology ,Acetylcysteine ,Up-Regulation ,chemistry ,Proteasome inhibitor ,biological phenomena, cell phenomena, and immunity ,Transcription Factor CHOP ,Protein Binding ,medicine.drug - Abstract
Hormonal induction triggers a cascade leading to the expression of CCAAT/enhancer-binding protein(C/EBP)alpha and peroxisome proliferator-activated receptor (PPAR) gamma, C/EBPalpha, and PPARgamma turns on series of adipocyte genes that give rise to the adipocyte phenotype. Previous findings indicate that C/EBPbeta, a transcriptional activator of the C/EBPalpha and PPARgamma genes, is rapidly expressed after induction, but lacks DNA-binding activity and therefore cannot activate transcription of the C/EBPalpha and PPARgamma genes early in the differentiation program. Acquisition of DNA-binding activity of C/EBPbeta occurs when CHOP-10, a dominant-negative form of C/EBP family members, is down-regulated and becomes hyperphosphorylated as preadipocytes traverse the G1-S checkpoint of mitotic clonal expansion. Evidences are presented in this report that lactacystin, a proteasome inhibitor, up-regulated the CHOP-10 expression, blocked the DNA-binding activity of C/EBPbeta, and subsequently inhibited MCE as well as adipocyte differentiation.
- Published
- 2006
5. Identification of a peroxisome proliferator responsive element (PPRE)-like cis-element in mouse plasminogen activator inhibitor-1 gene promoter
- Author
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Duan Ma, Hong Lei Liu, Qi Qun Tang, Xi Li, Hou Yan Song, De Guo Liu, Chun Gu Ma, Hai Yan Huang, Tanjing Song, and Jie Gen Chen
- Subjects
Transcription, Genetic ,Biophysics ,Adipose tissue ,Biology ,Ligands ,Response Elements ,Biochemistry ,Mice ,chemistry.chemical_compound ,Transactivation ,3T3-L1 Cells ,Adipocyte ,Plasminogen Activator Inhibitor 1 ,Adipocytes ,Animals ,Electrophoretic mobility shift assay ,Promoter Regions, Genetic ,Receptor ,Molecular Biology ,Cell Differentiation ,Promoter ,3T3-L1 ,Cell Biology ,Molecular biology ,PPAR gamma ,chemistry ,Plasminogen activator inhibitor-1 ,Peroxisome Proliferators - Abstract
PAI-1 is expressed and secreted by adipose tissue which may mediate the pathogenesis of obesity-associated cardiovascular complications. Evidence is presented in this report that PAI-1 is not expressed by preadipocyte, but significantly induced during 3T3-L1 adipocyte differentiation and the PAI-1 expression correlates with the induction of peroxisome proliferator-activated receptor gamma (PPARgamma). A peroxisome proliferator responsive element (PPRE)-like cis-element (-206TCCCCCATGCCCT-194) is identified in the mouse PAI-1 gene promoter by electrophoretic mobility shift assay (EMSA) combined with transient transfection experiments; the PPRE-like cis-element forms a specific DNA-protein complex only with adipocyte nuclear extracts, not with preadipocyte nuclear extracts; the DNA-protein complex can be totally competed away by non-labeled consensus PPRE, and can be supershifted with PPARgamma antibody. Mutation of this PPRE-like cis-element can abolish the transactivation of mouse PAI-1 promoter mediated by PPARgamma. Specific PPARgamma ligand Pioglitazone can significantly induce the PAI-1 expression, and stimulate the secretion of PAI-1 into medium.
- Published
- 2006
6. Autoactivation of the MDM2 E3 ligase by intramolecular interaction
- Author
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Tanjing Song, Qian Cheng, Lihong Chen, and Jiandong Chen
- Subjects
Ubiquitin-Protein Ligases ,Biology ,Catalysis ,Cell Line ,DDB1 ,Protein structure ,Ubiquitin ,Humans ,Protein Interaction Domains and Motifs ,Binding site ,Phosphorylation ,Molecular Biology ,Acidic Region ,Binding Sites ,Proto-Oncogene Proteins c-mdm2 ,Cell Biology ,Articles ,Ubiquitin ligase ,Protein Structure, Tertiary ,Biochemistry ,biology.protein ,Biophysics ,Mdm2 ,Tumor Suppressor Protein p53 ,Binding domain ,DNA Damage ,Protein Binding - Abstract
The RING domain ubiquitin E3 ligase MDM2 is a key regulator of p53 degradation and a mediator of signals that stabilize p53. The current understanding of the mechanisms by which MDM2 posttranslational modifications and protein binding cause p53 stabilization remains incomplete. Here we present evidence that the MDM2 central acidic region is critical for activating RING domain E3 ligase activity. A 30-amino-acid minimal region of the acidic domain binds to the RING domain through intramolecular interactions and stimulates the catalytic function of the RING domain in promoting ubiquitin release from charged E2. The minimal activation sequence is also the binding site for the ARF tumor suppressor, which inhibits ubiquitination of p53. The acidic domain-RING domain intramolecular interaction is modulated by ATM-mediated phosphorylation near the RING domain or by binding of ARF. These results suggest that MDM2 phosphorylation and association with protein regulators share a mechanism in inhibiting the E3 ligase function and stabilizing p53 and suggest that targeting the MDM2 autoactivation mechanism may be useful for therapeutic modulation of p53 levels.
- Published
- 2014
7. The NAD+ Synthesis Enzyme Nicotinamide Mononucleotide Adenylyltransferase (NMNAT1) Regulates Ribosomal RNA Transcription*
- Author
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Neha Kabra, Tanjing Song, Lihong Chen, Eric B. Haura, John M. Koomen, Jiandong Chen, and Leixiang Yang
- Subjects
Transcription, Genetic ,DNA damage ,Gene Dosage ,Repressor ,Down-Regulation ,Biochemistry ,Sirtuin 1 ,Transcription (biology) ,NMNAT1 ,Cell Line, Tumor ,Humans ,Gene Regulation ,Gene Silencing ,Nicotinamide-Nucleotide Adenylyltransferase ,Molecular Biology ,Nicotinamide-nucleotide adenylyltransferase ,biology ,Cell Death ,Nuclear Proteins ,RNA-Binding Proteins ,Acetylation ,Cell Biology ,Methyltransferases ,NAD ,Molecular biology ,RRNA transcription ,Gene Expression Regulation, Neoplastic ,Glucose ,Doxorubicin ,RNA, Ribosomal ,Gene Knockdown Techniques ,biology.protein ,NAD+ kinase ,Cell Nucleolus ,DNA Damage ,Protein Binding - Abstract
The chromosomal region encoding the nuclear NAD(+) synthesis enzyme nicotinamide mononucleotide adenylyltransferase (NMNAT1) is frequently deleted in human cancer. We describe evidence that NMNAT1 interacts with the nucleolar repressor protein nucleomethylin and is involved in regulating rRNA transcription. NMNAT1 binds to nucleomethylin and is recruited into a ternary complex containing the NAD(+)-dependent deacetylase SirT1. NMNAT1 expression stimulates the deacetylase function of SirT1. Knockdown of NMNAT1 enhances rRNA transcription and promotes cell death after nutrient deprivation. Furthermore, NMNAT1 expression is induced by DNA damage and plays a role in preventing cell death after damage. Heterozygous deletion of NMNAT1 in lung tumor cell lines correlates with low expression level and increased sensitivity to DNA damage. These results suggest that NMNAT1 deletion in tumors may contribute to transformation by increasing rRNA synthesis, but may also increase sensitivity to nutrient stress and DNA damage.
- Published
- 2013
8. Recognition of Histone H3K4 Trimethylation by the Plant Homeodomain of PHF2 Modulates Histone Demethylation*
- Author
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Bingdong Sha, Jingzhi Li, Min Gyu Lee, Ming Lu, Tanjing Song, Xiaobing Shi, Hong Wen, and Pu Yeh Kan
- Subjects
Protein Conformation ,Green Fluorescent Proteins ,Biology ,SAP30 ,Crystallography, X-Ray ,Biochemistry ,DNA, Ribosomal ,Methylation ,Histones ,Mice ,Histone demethylation ,Histone H1 ,Histone H2A ,Histone methylation ,Histone code ,Animals ,Humans ,Molecular Biology ,Plant Proteins ,Genetics ,Homeodomain Proteins ,Histone deacetylase 2 ,Cell Biology ,Protein Structure, Tertiary ,Histone methyltransferase ,Peptides ,Reports ,HeLa Cells - Abstract
Distinct lysine methylation marks on histones create dynamic signatures deciphered by the "effector" modules, although the underlying mechanisms remain unclear. We identified the plant homeodomain- and Jumonji C domain-containing protein PHF2 as a novel histone H3K9 demethylase. We show in biochemical and crystallographic analyses that PHF2 recognizes histone H3K4 trimethylation through its plant homeodomain finger and that this interaction is essential for PHF2 occupancy and H3K9 demethylation at rDNA promoters. Our study provides molecular insights into the mechanism by which distinct effector domains within a protein cooperatively modulate the "cross-talk" of histone modifications.
- Published
- 2010
9. Involvement of Cytoskeleton-associated Proteins in the Commitment of C3H10T1/2 Pluripotent Stem Cells to Adipocyte Lineage Induced by BMP2/4
- Author
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Pengyuan Yang, Qun He, Hai Yan Huang, Qi Qun Tang, Tanjing Song, Hao Jie Lu, Xi Li, Yi Ming Li, Ling Ling Hu, and Xia Sun
- Subjects
Pluripotent Stem Cells ,Proteomics ,Bone Morphogenetic Protein 2 ,Lysyl oxidase ,Bone Morphogenetic Protein 4 ,Biology ,Biochemistry ,Bone morphogenetic protein 2 ,Analytical Chemistry ,Protein-Lysine 6-Oxidase ,Mice ,chemistry.chemical_compound ,Adipocyte ,Adipocytes ,Biomarkers, Tumor ,Animals ,Cell Lineage ,Induced pluripotent stem cell ,Molecular Biology ,Extracellular Matrix Proteins ,Gene knockdown ,Research ,Mesenchymal stem cell ,Reproducibility of Results ,Tumor Protein, Translationally-Controlled 1 ,alpha-Crystallin B Chain ,Molecular biology ,Actins ,Up-Regulation ,Cell biology ,Cytoskeletal Proteins ,Bone morphogenetic protein 4 ,chemistry ,Gene Knockdown Techniques ,Signal transduction ,Signal Transduction - Abstract
The developmental pathway that gives rise to mature adipocytes involves two distinct stages: commitment and terminal differentiation. Although the important proteins/factors contributing to terminal adipocyte differentiation have been well defined, the proteins/factors in the commitment of mesenchymal stem cells to the adipocyte lineage cells have not. In this study, we applied proteomics analysis profiling to characterize differences between uncommitted C3H10T1/2 pluripotent stem cells and those that have been committed to the adipocyte lineage by BMP4 or BMP2 with the goal to identify such proteins/factors and to understand the molecular mechanisms that govern the earliest stages of adipocyte lineage commitment. Eight proteins were found to be up-regulated by BMP2, and 27 proteins were up-regulated by BMP4, whereas five unique proteins were up-regulated at least 10-fold by both BMP2/4, including three cytoskeleton-associated proteins (i.e. lysyl oxidase (LOX), translationally controlled tumor protein 1 (TPT1), and αB-crystallin). Western blotting further confirmed the induction of the expression of these cytoskeleton-associated proteins in the committed C3H10T1/2 induced by BMP2/4. Importantly, knockdown of LOX expression totally prevented the commitment, whereas knockdown of TPT1 and αB-crystallin expression partially inhibited the commitment. Several published reports suggest that cell shape can influence the differentiation of partially committed precursors of adipocytes, osteoblasts, and chondrocytes. We observed a dramatic change of cell shape during the commitment process, and we showed that knockdown of these cytoskeleton-associated proteins prevented the cell shape change and restored F-actin organization into stress fibers and inhibited the commitment to the adipocyte lineage. Our studies indicate that these differentially expressed cytoskeleton-associate proteins might determine the fate of mesenchymal stem cells to commit to the adipocyte lineage through cell shape regulation.
- Published
- 2011
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