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Fu-Chu He

Publications and source records attributed to Fu-Chu He.

At least 19 recordsLinked to original sources
PubMed2006

Theophylline attenuates microwave-induced impairment of memory acquisition.

Numerous studies have shown that acute microwave exposure causes cognitive deficits in animals, possibly via hyperthermia, but the biological effect of microwave exposure on memory processing is still unknown. The release of adenosine is demonstrated to be a general way for the cells to respond to metabolically stressful conditions such as hypoxia and ischemia. The present study aimed to examine whether adenosine mediates biological effects of microwave exposure on memory processing using a continuous multiple-trial inhibitory avoidance task. Results demonstrated that microwave exposure for 20 min before training impaired memory acquisition and retention performance in mice, assessed by the number of training trials and by latency to enter the dark compartment. The mice exposed to microwave radiation showed a dose-dependent hyperthermia. Moreover, the cell numbers of hippocampus were decreased in the mice receiving microwave exposure at an average power density of 50 mW/cm(2), indicating the anatomical correlation to hippocampal-amygdaloid structures corresponding with the memory disrupt of the mice. Administration of theophylline, a nonspecific adenosine receptor antagonist, 30 min before microwave exposure, completely antagonized the impairment of inhibitory avoidance acquisition but not retention. These results suggest that the adenosine regulation pathway was partially involved in microwave-induced impairment of inhibitory avoidance memory.

Adenosine↗
PubMed2006

[Research advances in expression profiling of mitochondrial proteins].

As an important subcellular organelle, the mitochondrion plays an important role in many physiological and pathological processes. This article reviews the most recent studies in the significance, technological aspects, problems and future prospects of expression profiling of mitochondrial proteins.

Animals↗
PubMed2006

[Progress in the study of KRAB zinc finger protein].

The zinc finger proteins containing the Kruppel-associated box domain (KRAB) constitute the largest single family of transcriptional regulators in mammals. Many genes encoding members of this family are arranged in clusters. KRAB-containing proteins are characterized by the presence of 4 and over 30 C2H2 zinc-finger motifs and a KRAB domain near the amino terminus of the protein. KRAB domain behaving as a protein-protein interaction domain could bind to corepressor proteins and/or transcription factors, and that the KRAB-containing proteins could act as a repressor or corepressor and play a key role in transcriptional repression. Members of the family are involved in embryonic development, cell differentiation, cell proliferation, apoptosis, neoplastic transformation and cell cycle regulation.

Amino Acid Sequence↗
PubMed2006

[The application of large-scale yeast two-hybrid to study protein--protein interaction].

The principle of yeast two-hybrid were summarized, the basis for large scale yeast two-hybrid screening of protein-protein interaction was given and the main application of yeast two-hybrid in large scale screening of protein-protein interaction was presented. The problems of large scale yeast two-hybrid screening of protein-protein interaction were also discussed. Because there were a lot of false positives and false negatives in the result of protein-protein interaction obtained by large-scale yeast two-hybrid screening, the employment of other methods to study protein-protein interaction in large scale in parallel was proposed if possible.

Animals↗
PubMed2006

[The application of RNAi technology in transgenic mice].

RNA interference (RNAi) has been extensively used for sequence-specific silencing of gene function in C. elegans, Drosophila, mouse and rat. The generation of RNAi transgenic mice made it possible to knock down gene expression at the whole organism level in mammalian species. In this review we described the design strategy of RNAi vectors, compared the difference of gene knock-down from knock-out, and summarized the advantages and unresolved issues concerning RNAi transgenic mice. The contribution of RNAi transgenic mice to functional genomics and of its prospect for application were also discussed.

Animals↗
PubMed2006

[Effect of the new human transcription factor hBKLF on the proliferation, differentiation of K562 cell line and hemoglobin synthesis].

The human basic Krüppel-like factor (hBKLF) is a newly cloned human transcription factor from the cDNA library of fetal liver. It belongs to the Krüppel-like transcription factor family. Previous expression study showed that it is a hematopoietic related factor. This study was aimed to investigate the effect of hBKLF on cell proliferation, differentiation and hemoglobin synthesis by using K562 cell line as model. The sense and antisense expression plasmids of hBKLF were constructed, and transfected into K562 cells by lipofectamine. After G418 selection for 4 weeks, the cell line with stable expression of the gene was obtained. Then the hBKLF expression level, proliferation ability, colony formation and hemoglobin production were detected by RT-PCR and Western blot, MTT method, methyl cellulose semisolid culture method and benzidine test respectively. The morphologic change of cell was observed with inverted microscope. The results showed that the sense plasmid could increase hBKLF level and antisense plasmid could decrease hBKLF expression. When hBKLF level was down-regulated, K562 cells could proliferate more quickly and synthesize more hemoglobin. But there were no differences in colony formation ability and no apparent morphologic change. It is concluded that hBKLF can inhibit hematopoietic cell proliferation and hemoglobin synthesis. It is suggested that hBKLF plays an important role in the proliferation and differentiation of hematopoietic cells.

Animals↗
PubMed2005

High fidelity PCR with an off/on switch mediated by proofreading polymerases combining with phosphorothioate-modified primer.

In the initial report, introducing a single phosphorothioate modification at the very 3' terminus of the oligodeoxynucleotide primer has been shown to effectively protect the oligodeoxynucleotide degradation due to the 3' exonuclease activity. In this study, we reported a novel finding that phosphorothioate modification at the 3' end of primers could not only effectively prevent the primer from degradation, but could also mediate an off-switch extension by Pfu polymerase when primers also carry single or multiple mismatched bases located in the first eight bases of the 3' terminus. This suggests that the combination of 3' phosphorothioate-modified primers with exo+ polymerases such as Pfu constituted an on/off switch, which allows perfectly matched primers to be extended but not mismatched primers. Furthermore, we found that polymerases with different fidelities showed different efficiencies in turning off mismatched-primer mediated extension. So we described here a SYBR green-based real-time quantitative PCR assay for the detection of abundance level of gene expression that did not require fluorescently labeled gene-specific probes or complicated primer combinations. The emergence of real-time quantitative RT-PCR technology is thus suited for a diverse application with a need for high-throughput methods to detect and quantify different gene expressions by way of simplicity, versatility, and accuracy, and thus could complement global microarray-based expression profiling strategies.

DNA Primers↗
PubMed2005

[Molecular mechanism of specific induction of apoptosis in tumor cells by apoptin].

Apoptin, a small protein derived from chicken anemia virus, can specifically induce apoptosis in transformed cells or tumor cells, but not in normal cells. The tumor specificity of Apoptin relates to its subcellular localization. In transformed cells or tumor cells, Apoptin migrates to the nuclei, whereas in non-transformed cells, it remains mainly within the cytoplasm. Phosphorylation is responsible for the nuclear localization of Apoptin. In tumor cells, Apoptin is phosphorylated, then translocates into the nuclei, and induces cell apoptosis. Apoptin-induced apoptosis does not depend on functional p53, and can't be inhibited by overexpression of Bcl-2 and Bcl-xL, but caspase-3 activation is necessary for Apoptin-induced rapid apoptosis. Apoptin has a strong tendency to aggregate, and exists as aggregates in living cells, but in vivo formation and dissociation of the aggregates are not required for apoptosis-inducing activity of Apoptin. It is possible that Apoptin's ability to bind DNA closely relates to its ability to induce apoptosis.

Adenoviridae↗
PubMed2005

[Strategy for the protein identification of human proteome expression profile: selection of searching database].

Widely used method of protein identification for high-throughout proteome expression profile studies was database-dependent, so the selection of databases for the protein identification was very important. Despite the deficiency of available human protein databases, the complementarity of human proteins could be got mainly from human genome but not from the protein databases of other organisms. According to the comparison of the current protein databases from different aspects, IPI was recommended for the basic identification for the studies of human proteome expression profile, and other human protein or nucleic acid databases were needed for the complementary identification and novel protein mining.

Animals↗
PubMed2004

Protein product encoded by a human novel gene E9730 enhances AP-1 activity through interacting with Jab1.

A novel human gene, named E9730 (a clone number of fetal liver cDNA library), has been identified from more than 14,000 expressed sequence tags (ESTs) based on our large scale sequencing of human fetal liver cDNA libraries. Although sequencing of this novel human gene indicates that it is a leucine zipper protein, the function of E9730 and its homongous genes among species is unknown yet. To find out physiological functional clue of E9730, the yeast two-hybrid system was used to screen the E9730-interacting protein(s), and one clone containing a cDNA insert with almost the entire coding sequence (amino acids 39 C335) of human Jab1 (Jun-activating domain binding protein 1) that interacted specifically with E9730 was identified. A specific association between Jab1 and E9730 was shown by co-immunoprecipitation and co-localization experiments. Furthermore, the data indicated that E9730 appeared to enhance Jab1-induced AP-1 activity in a concentration-dependent manner and Jab1 may be involved in the intracellular signaling transduction from E9730 to AP-1.

Amino Acid Sequence↗
PubMed2004

A putative NES mediates cytoplasmic localization of Apoptin in normal cells.

Apoptin, a protein expressed by chicken anemia virus, is found predominantly in the cytoplasm in normal cells, whereas it localizes in the nucleus in transformed and malignant cells. However, the mechanisms that regulate the different subcellular localization of Apoptin in normal and tumor cells have not been fully clarified. In this work, a putative nuclear export signal (NES) in Apoptin was predicted. It was testified that the putative NES (pNES) of Apoptin was not a functional NES, but actually acted as a cytoplasmic retention signal. Deletion of the pNES led to the nuclear accumulation of Apoptin in normal cells. In addition, when a strong nuclear localization signal was introduced into Apoptin, it exclusively translocated to the nucleus in normal cells. These observations indicated that the cytoplasmic localization of Apoptin in normal cells results from the balance between cytoplasmic retention and nuclear import. On the other hand, the pNES was also proved to be necessary for Apoptin multimerization. Mutants lacking the pNES did not form obviously visible globular aggregates in normal or tumor cells.

Active Transport, Cell Nucleus↗
PubMed2004

[A motif-based scanning approach for prediction of protein phosphorylation].

Scansite is a short linear motif-based scanning approach established in the latest two years. It's accessible over the World Wide Web and can be used to identify sequence motifs likely to be phosphorylated by specific protein kinases or likely to bind to specific protein domains such as 14-3-3, SH2 and SH3 domains. The usage and function of the potent approach were reviewed and compared with previously established tools for phosphorylation prediction. The facing problems and application outlook of Scansite in prediction of cell signaling networks within proteomes were also presented.

Amino Acid Motifs↗
PubMed2003

[Subcellular localization of basic Krüppel-like factor].

To understand the function of basic Krüppel-like factor (BKLF), it was confirmed by direct fluorescence and indirect fluorescence observation that hBKLF was localized in nucleus, and distributed throughout nucleoplasm in a speckled pattern, except the nucleoli. This pattern is similar to many but not all transcription factors. To clarify the specific sequence responsible for its nuclear localization, a series of deletion mutants of GFP/hBKLF were constructed. By observing their subcellular localization, it was found that the three zinc fingers of hBKLF and the N-terminal aside from the fingers all served as nuclear localization signals (NLS); the sub-NLS of hBKLF was located in the N-terminus, including the CtBP-binding motif and the proline rich domain. These results provided a basis for further clarifying the function of BKLF.

Animals↗
PubMed2003

[Transcriptional regulation of gamma- and epsilon-globin genes by basic Krüppel-like factor].

To study the transcription regulatory function of basic Krüppel-like factor (BKLF)on gamma- and epsilon-globin genes, recombinant expression vectors containing the full-length human BKLF gene, and a deletion mutant that lost N-terminal 40 amino acids, were constructed and used, respectively, to transiently transfect COS7 cells in order to assay their reporter activities. Results showed that hBKLF was able to repress the activity of gamma- and epsilon-globin gene promoters, while the antisense nucleic acid specific for hBKLF activated the transcription of these promoters. Deleting 40 amino acids from N-terminus did not influence the transcriptional repression of hBKLF. The stimulatory function of FKLF on gamma- and epsilon-globin gene promoters was also significantly reduced by hBKLF. In addition, BKLF bound the CACCC element in the SHP1 (SH2-containing protein tyrosine phosphatase 1) gene promoter. These results suggest that gamma- and epsilon-globin genes may be transcriptional targets of BKLF, providing evidence for further studies on the role of BKLF in participating the transcriptional regulation of haemocyte-specific genes.

3T3 Cells↗
PubMed2003

[cDNA cloning, subcellular localization and tissue expression of a new human Krüppel-like transcription factor: human basic Krüppel-like factor (hBKLF)].

The FLD4585 clone from the cDNA library of human fetal liver may encode a hematopoietic related transcription factor. Here we tried to clone its full-length cDNA from the 22 weeks-gestation human fetal liver and study its functional domains, genomic structure, chromosomal localization, subcellular site and expression pattern. To obtain the full-length cDNA of FLD4585 clone, 5' RACE technique was used. Bioinformatics was used to analyze its genomic structure, chromosomal localization and potential functional domains. Its subcellular localization was shown by GFP fusion technique. The expression pattern was studied by Northern blot, RT-PCR and Western blot. The results show the full-length cDNA encoded by FLD4585 clone is 1810 bp long and encodes a 345 amino acids protein with high homology to mouse BKLF (basic Krüppel-like factor). Its characteristic C-terminal three contiguous C2H2 zinc fingers place it within the family of Krüppel-like factors. Bioinformatics studies show hBKLF gene spans over 33 kb on chromosome 4p15.2-4p16.1 and contains 6 exons and 5 introns. GFP-hBKLF fusion technique showed hBKLF was present in the nuclei of COS-7 cells in a punctate pattern, whereas it was absent in the nucleoli. By Northern blot, hBKLF has two transcripts, one between 4.4 kb-7.5 kb and the other between 1.35 kb-2.4 kb. The larger transcript exists widely in human tissues. However, the smaller transcript was more restricted in blood leukocytes, liver and bone marrow. RT-PCR showed erythrocytes and granulocytes could both express hBKLF and its level increased as they matured. The expression level in fetal liver decreased as it developed towards adult liver and its hematopoietic function gradually lost. Taken together, in this paper we have successfully cloned the full length cDNA of hBKLF. Expression study suggests it may have broad functions in vivo, especially the functions in hematopoietic tissues.

Amino Acid Sequence↗
PubMed2003

[Gene prediction and function research of SARS-CoV(BJ01)].

Through reading the articles, this study points out the shortage of gene prediction and function research about SARS-CoV, and predict it again for developing effective drugs and future vaccines. Using twelve gene prediction methods to predict coronavirus known genes, we select four better methods including Heuristic models, Gene Identification, ZCURVE_CoV and ORF FINDER to predict SARS-CoV(BJ01), and use ATGpr for analyzing probability of initiation codon and Kozak rule, search transcription regulating sequence(TRS) in order to improve the accuracy of predicted genes. Twenty-one probable new genes with more than 50 amino acids have been obtained excluding 13 ORFs which are similar to the genes of NCBI and relative articles. For predicted proteins, we use ProtParam to analyse physical and chemical features; SignalP to analyse signal peptide; BLAST, FASTA to search similar sequences; TMPred, TMHMM, PFAM and HMMTOP to analyse domain and motif in order to improve reliability of gene function prediction. At the same time, we separate the 21 ORFs into four classes using codition of four gene prediction methods, match score, match expection and match length between predicted gene and Coronavirus known gene. In the end, we discuss the results and analyse the reasons.

Computational Biology↗
PubMed2003

[The genome comparison of SARS-CoV and other coronaviruses].

The genome comparison of inter-species and intra-species can give us much information about the origin and evolution of viruses. There are 137 mutation sites in the 17 genomes of SARS-CoV,and the mutation rate is about 8.04 x 10(-3) substitution/site/year. The distribution of the segregating sites is not steady,the most variable region appears in S1 protein,and the nucleotide sequence of RNA-dependent RNA polymerase has very few mutation sites. The substitution bias of nucleotide acids and amino acids indicates the non-random drift products. The comparison of genome structures of SARS-CoV and other coronaviruses shows that SARS-CoV and IBV share the same genome structure. Phylogenetic analyses of conserved genes of coronaviruses indicate that SARS-CoV is a new branch of coronaviruses and appears more close to the group II coronaviruses. Interestingly,SARS-CoV shares some different features with different groups of coronaviruses. Additional analyses show that the first ORFs between S and E genes of some coronaviruses are transmembrane proteins and share the common motif,indicating the possible common ancestor. From the host distribution of different groups of coronaviruses and the phylogeny of s2m,we can deduce that avian is the probable natural host of SARS-CoV.

English Abstract↗