Epigenetics is aimed to study the heritable changes in gene expression patterns independent of alterations in genomic DNA sequence structure, and the mechanisms of translation from genotype to phenotype. In recent years, compelling evidence gathered supports a role of epigenetic alterations in the pathogenesis of lymphatic system tumors. For example, recent data from multiple laboratories indicate that several hundred genes, involving dozens of critical molecular pathways, are epigenetically suppressed in acute lymphocytic leukemia; a panel of methylation markers can be used for additional risk stratification of chronic lymphocytic leukemia patients; based on the epigenetic profiles, the class prediction models in gray zone lymphoma can be established; the epigenetic silencing of microRNAs in multiple myeloma generally appears to have intact P53 function; epigenetic therapies have broader implication and high potential for the development of immunotherapeutic strategies and so on. In this review, the latest advances of epigenetic study and the prospect of epigenetic therapy for tumors in lymphatic system are summarized.
Amino Acid Motifs ; DNA Methylation ; Epigenesis, Genetic ; Histones ; genetics ; Humans ; Lymphatic Diseases ; genetics ; Lymphatic System ; Neoplasms ; genetics

Human astrovirus (HAstV) is one of the leading causes of actue virual diarrhea in infants. HAstV-induced epithdlial cell apoptosis plays an important role in the pathogenesis of HAstV infection. Our previous study indicated that HAstV non-structural protein nsPla C-terminal protein nsPla/4 was the major apoptosis functional protein and probably contained the main apoptosis domains. In order to screen for astrovirus encoded apoptotic protien, nsPla/4 and six turncated proteins, which possessed nsPla/4 protein different function domain ,were cloned into green fluorescent protein (GFP) vector pEG-FP-N3. After 24-72 h transfection, the fusion protein expression in BHK21 cells, was analysis by fluorescence microscope and Western blot. The results indicated seven fusion proteins were observed successfully in BHK21 cell after transfected for 24 h. Western blot analysis showed that the level of fusion protein expressed in BHK21 cells was increased significantly at 72h compared to 48h in transfected cells. The successful expression of deletion mutants of nsPla/4 protein was an important foundation to gain further insights into the function of apoptosis domains of nsPla/4 protein and it would also provide research platform to further confirm the molecule pathogenic mechanism of human astrovirus.
Amino Acid Motifs ; Astroviridae Infections ; virology ; Humans ; Mamastrovirus ; genetics ; metabolism ; Mutation ; Sequence Deletion ; Transfection ; Viral Nonstructural Proteins ; chemistry ; genetics ; metabolism

Knowledge of the evolution of pathogens is of great medical and biological significance to the prevention, diagnosis, and therapy of infectious diseases. In order to understand the origin and evolution of the SARS-CoV (severe acute respiratory syndrome-associated coronavirus), we collected complete genome sequences of all viruses available in GenBank, and made comparative analyses with the SARS-CoV. Genomic signature analysis demonstrates that the coronaviruses all take the TGTT as their richest tetranucleotide except the SARS-CoV. A detailed analysis of the forty-two complete SARS-CoV genome sequences revealed the existence of two distinct genotypes, and showed that these isolates could be classified into four groups. Our manual analysis of the BLASTN results demonstrates that the HE (hemagglutinin-esterase) gene exists in the SARS-CoV, and many mutations made it unfamiliar to us.
Amino Acid Motifs ; Amino Acid Substitution ; Base Composition ; Codon ; genetics ; Computational Biology ; DNA Mutational Analysis ; Evolution, Molecular ; Gene Transfer, Horizontal ; Genetic Variation ; Genome, Viral ; Phylogeny ; SARS Virus ; genetics

According to the genomic sequence of foreign four PLRV isolates, three pairs of specific primer were designed and synthesized. The cDNA of the ORF2a gene of PLRV-Ch was synthesized by reverse transcription and followed by Polymerase Chain Reaction amplication. The synthesized 3' and 5' cDNA fragment of the PLRV-Ch ORF2a gene were inserted into pUC19 and cloned in E. coli JM109 and were sequenced respectively. The middle cDNA fragment were directly sequenced. The homology of nucleotide sequence of PLRV-Ch compared with PLRV-S (Scotland, UK), PLRV-N(Netherlands), PLRV-A(Australia) and PLRV-C(Canada) were 98.96%, 98.70%, 94.79%, 97.5%, the homology of putative amino acid sequence are 97.97%, 97.97%, 89.69%, 95.94%. In 3' region of ORF2a gene a slippery sequence for-1 frameshift and its downstream "stem-loop" or "pseudoknot" and upstream nucleotide sequence repeats were found. Authors suggested that the nucleotide repeat sequences characteristic for PLRV could form a tight successively folded complementary double stranded regions and hairpins. This structure possibly has something to do with-1 frameshift. The amino acid sequence of C terminus region of 70 kD protein translated by motif IV has a protease characteristic motif and a helicase motif IV. The amino acid sequence of polypeptide translated by ORF2a gene undergoing frameshift has a single-stranded nucleic acid binding protein-like characteristic motif.
Amino Acid Motifs ; Luteovirus ; genetics ; Open Reading Frames ; genetics ; Protein Folding ; Reverse Transcriptase Polymerase Chain Reaction ; Solanum tuberosum ; virology ; Viral Proteins ; chemistry ; genetics

The EF-hand superfamily is a large group of proteins which contain EF-hand motif formed by helix-loop-helix. These proteins always have the ability of binding metal ions or forming dimmers. Troponin C, known as having ability of binding Ca2+, is one member of the EF-hand superfamily. Troponin C interacts with troponin I and troponin T, forming a troponin complex which takes part in regulating muscle contraction. It is interesting that troponin C was also found in non-muscular tissue, and its function was proved to be different from that of troponin C found in muscular tissue. To date, a lot of researches about troponin C have been carried out widely. However, most of them focused on vertebrate, seldom were done on invertebrate. Our group carried out a research on troponin C from silkworm, a model organism of insects, aiming to clarify the structure and function of silkworm troponin C. Here, we mainly discuss the characters of the EF-hand superfamily and the classification, structure and function of troponin C . We also introduced our work about silkworm troponin C briefly, hoping of making a little contribution to the research of invertebrate troponin C.
Amino Acid Sequence ; Animals ; Binding Sites ; genetics ; Bombyx ; genetics ; metabolism ; Calcium ; metabolism ; EF Hand Motifs ; Molecular Sequence Data ; Phylogeny ; Protein Binding ; Troponin C ; classification ; genetics ; metabolism

OBJECTIVETo investigate the primary structure and heterogenenity of P gene region including YMDD motif in hepatitis B virus.

METHODSFrom serum samples collected from 4 patients who had never been treated with anti-viral drugs, DNA fragments of 1057bp long of P gene were amplified and cloned into pUC19. Twenty positive clones were chosen randomly from each sample. The YMDD motif mutation was detected by mismatched PCR-RFLP. Finally last ten positive clones of two samples were sequenced.

RESULTSNucleotide mutation rates among clones of Sample 1 and 2 were 0.3% - 1.1%, 0.4% - 1.7%, respectively. Among 80 clones, the variations from YMDD to YMGD were revealed in two clones.

CONCLUSIONThere are HBV quasispecies in the P gene region including YMDD motif of hepatitis B virus and a novel mutation of YMDD motif in the sera of patients without being therapied by anti-viral drugs.

Adult ; Amino Acid Motifs ; Base Sequence ; Gene Products, pol ; genetics ; Hepatitis B virus ; genetics ; Humans ; Male ; Molecular Sequence Data ; Mutation ; Polymerase Chain Reaction ; Polymorphism, Restriction Fragment Length

This study was performed to investigate the effects of different regions of the Autographa califor nica multiple nucleopolyhedrovirus envelope protein E25 on its trafficking into nucleus and nuclear localization in host cells and on virus replication. Fourteen recombinant bacmids, each containing an e25 mutant with substitution or insertion of egfp, in the absence or presence of the native e25, were constructed and used to transfect Sf9 cells. The E25-EGFP fusion proteins and native E25 expressed in the cells transfect ed with individual recombinant bacmid were traced by autofluorescence from EGFP or by immuno-fluorescence assays. Confocal microscopy revealed that the E25-EGFP fusion protein with the N-domain (2-45aa) of E25 substituted by EGFP only distributed in the cytoplasm in transfected cells; and the fusion protein with EGFP inserted at the laa/2aa site of E25 completely remained outside of the nucleus and resided along the nuclear membrane. The E25-EGFPs with 46-118aa of E25 substituted by EGFP or with EGFP inserted at the 118aa/119aa site were present outside, across from the nuclear membrane or in nuclear plasm in dot-like shapes. The fusion proteins with the C-domain substituted by EGFP or with EGFP inserted at the site of 45/46aa or at the C-terminal formed a condensed ring or spread throughout the nucleus, in a similar manner to the E25 distributed in the cells transfected by the e25-knockout repair bacmid. These results prove that the N-terminal domain is critical for nuclear transportation of E25 and possibly to its position on the cytoplasm membrane as well; and the sequence downstream of the N-terminal domain also affects trafficking and nuclear localization of the protein. In cells transfected with bacmids containing both the native e25 and individual e25-egfp mutants, the E25-EGFP fusion proteins co-localized with E25 individually, showing similar patterns of subcellular localization as E25 mutants in the absence of native E25 in most cases, suggesting that the E25 likely exists and functions as dimmers or polymers. Production of infectious BV was dramatically reduced and even completely eliminated in most cases, either in the absence or presence of the native e25.
Amino Acid Motifs ; Animals ; Cell Nucleus ; metabolism ; virology ; Mutation ; Nucleopolyhedrovirus ; chemistry ; genetics ; physiology ; Protein Transport ; Spodoptera ; virology ; Viral Proteins ; chemistry ; genetics ; metabolism ; Virus Release ; Virus Replication

OBJECTIVETo investigate the influence of vascular endothelial growth factor (VEGF) gene modification on skin substitute grafted on nude mice.

METHODSHuman fibroblasts were transfected with VEGF adenovirus vector. Then the genetic modified fibroblasts were seeded on patches of Integra artificial skin. Twenty-four hours later, the Integra patches were grafted onto full-thickness skin defects on nude mice. Seventy-two nude mice were divided into experiment (n = 18, E, with fibroblasts seeded on Integra which were transfected by adenovirus containing VEGF in advance), GFP control (n = 18, the fibroblasts were transfected with adenovirus containing labelled GFP segment as same as that in E group, but containing no VEGF gene), Fb control (n = 18, without gene transfection), and control (n = 18, no fibroblast was seeded on Integra) groups. The survival rate, the revascularization process and the histological changes in the grafts in gene modified group (experimental group) and control groups were observed and analyzed.

RESULTSThe revascularization condition in the experimental group was much better than that in the control group. The grafts adhered firmly to the wound during early postoperation stage, and were more prone to bleed when separated from the wound. The survival rate was obviously higher, while the infection rate was much lower in experimental group (100.0%) compared with the control groups (83.3%, 75.0%, 77.8%, respectively) (P < 0.05).

CONCLUSIONHigh expression of VEGF by gene modification can promote the vascularization process of skin substitute, hence improve the grafting result.

Amino Acid Motifs ; Animals ; Cells, Cultured ; Female ; Fibroblasts ; cytology ; Humans ; Mice ; Mice, Nude ; Neovascularization, Physiologic ; genetics ; Skin ; cytology ; Skin Transplantation ; Skin, Artificial ; Transfection ; Vascular Endothelial Growth Factor A ; genetics

OBJECTIVE: To establish 293T cell lines stably expressing Calpain-cleavage related α3 cytoplasmic tail mutants, and to explore the effect of amino acid motifs in integrin β3 cytoplasmic tail on αⅡbβ3-mediated cell function. METHODS: 293T cell lines stably co-expressing human wild type integrin αⅡb and full length β3 or mutant β3, including β3-ΔNITY (β3 cytoplasmic tail NITY motif deleted), β3-Δ754 (β3 cytoplasmic tail TNITYRGT motif deleted) and β3-Δ759 (β3 cytoplasmic tail RGT motif deleted) were established. Spreading and adhesion of these stable cell lines on immobilized fibrinogen were tested. RESULTS: 293T-αⅡbβ3ΔNITY, 293T-αⅡbβ3Δ754, 293T-αⅡbβ3Δ759 and 293T-αⅡbβ3 cell lines were successfully established. Compared with the 293T cells, 293T-αⅡbβ3 cells which expressed full β3, possessed well adhesion and spread ability on immobilized fibrinogen, suggesting it can be as a surrogate for platelet. Compared with 293T-αⅡbβ3 cells, the 293T-αⅡbβ3ΔNITY cells showed a partial impairment of adhesion and spreadability on immobilized fibrinogen. while the 293T-αⅡbβ3Δ754 cells and 293T-αⅡbβ3Δ759 cells failed to adhere or spread on immobilized fibrinogen. CONCLUSION To the cell spreading function mediated by integrin β3, RGT motif is vital, while NITY can be dispensable. These established 293T cell lines stably expressing different β3 mutants provide a solid basis for a further analysis of mass spectrometry.
Amino Acid Motifs ; Animals ; CHO Cells ; Cell Adhesion ; Cricetinae ; Cricetulus ; HEK293 Cells ; Humans ; Integrin beta3 ; genetics ; metabolism ; Platelet Glycoprotein GPIIb-IIIa Complex ; genetics ; metabolism ; Signal Transduction

Newcastle disease (ND) caused by virulent Newcastle disease virus (NDV) is a highly contagious viral disease of poultry. Virulent NDVs characteristically have a multibasic amino acid sequence (virulence motif) such as (112)RRQKRF(117) at the cleavage site of the precusor fusion (F0) protein. The antigenic and immunogenic characteristics of the virulence motif (112)RRQKRF(117) in the F0 protein of virulent NDVs were investigated. Epitope mapping analysis revealed that a RRQKRF-specific monoclonal antibody 4G2 recognized the KRF section of the motif. A synthetic peptide bearing the RRQKRF motif reacted strongly with sera from virulent NDV (with RRQKRF motif)-infected chickens. These sera also showed reactivity to peptides bearing other virulence motifs ((112)KRQKRF(117), (112)RRQRRF(117) and (112)RRRKRF(117)) but not an avirulence motif ((112)GRQGRL(117)) by ELISA. The synthetic bearing RRQKRF motif reacted with 60% to 91% of sera taken from surviving chickens on ND outbreak farms but not with sera from vaccinated birds, even though most of the sera had antibody to NDV due to vaccination. This indicates that the virulence motif has the potential to differentiate virulent NDV infected birds from vaccinated birds.
Amino Acid Motifs/*immunology ; Amino Acid Sequence ; Animals ; Chickens ; Enzyme-Linked Immunosorbent Assay/veterinary ; Epitope Mapping/veterinary ; Newcastle Disease/*immunology ; Newcastle disease virus/*genetics/pathogenicity ; Poultry Diseases/*immunology/*virology ; Serologic Tests/veterinary ; Viral Fusion Proteins/*genetics/immunology ; Virulence/genetics