Biomedical subjects

Chang-Jen Huang

Publications and source records attributed to Chang-Jen Huang.

25 records · Page 2Linked to original sources

PubMed2003

Proximal upstream region of zebrafish bone morphogenetic protein 4 promoter directs heart expression of green fluorescent protein.

We examined the activity of the bone morphogenetic protein 4 (BMP4) promoter in zebrafish embryos via transient and stable transgenic expression analyses in order to obtain a better understanding of the regulation of BMP4 tissue-specific expression. Transient expression studies showed that the 9.0-kb BMP4 promoter/upstream region drove green fluorescent protein (GFP) expression mainly in the heart. Deletion analyses indicated the existence of multiple regulatory elements in the 7.5-kb BMP4 promoter/proximal upstream region. In addition, a coinjection experiment further demonstrated the 2.4-kb Bgl II-Hind III DNA region contains major positive regulatory elements. In addition, stable transgenic lines were established to further confirm the heart-specificity of this segment in BMP4 promoter. The results showed that GFP was mainly localized in the myocardium of developing ventricles of 48-hpf (hours postfertilization), 72-hpf, and 100-hpf transgenic F(1) embryos. Together, these results indicate that the 7.5-kb BMP4 promoter/proximal upstream region specifically contains regulatory elements for BMP4 expression in the heart, while regulatory elements for other endogenous BMP4-expressing tissues may reside in more distal regions and/or in introns.

Animals↗

PubMed2003

Genomic structure, expression and characterization of a STAT5 homologue from pufferfish (Tetraodon fluviatilis).

The STAT5 (signal transducer and activator of transcription 5) gene was isolated and characterized from a round-spotted pufferfish genomic library. This gene is composed of 19 exons spanning 11 kb. The full-length cDNA of Tetraodon fluviatilis STAT5 (TfSTAT5) contains 2461 bp and encodes a protein of 785 amino acid residues. From the amino acid sequence comparison, TfSTAT5 is most similar to mouse STAT5a and STAT5b with an overall identity of 76% and 78%, respectively, and has < 35% identity with other mammalian STATs. The exon/intron junctions of the TfSTAT5 gene were almost identical to those of mouse STAT5a and STAT5b genes, indicating that these genes are highly conserved at the levels of amino acid sequence and genomic structure. To understand better the biochemical properties of TfSTAT5, a chimeric STAT5 was generated by fusion of the kinase-catalytic domain of carp Janus kinase 1 (JAK1) to the C-terminal end of TfSTAT5. The fusion protein was expressed and tyrosine-phosphorylated by its kinase domain. The fusion protein exhibits specific DNA-binding and transactivation potential toward an artificial fish promoter as well as authentic mammalian promoters such as the beta-casein promoter and cytokine inducible SH2 containing protein (CIS) promoter when expressed in both fish and mammalian cells. However, TfSTAT5 could not induce the transcription of beta-casein promoter via rat prolactin and Nb2 prolactin receptor. To our knowledge, this is the first report describing detailed biochemical characterization of a STAT protein from fish.

Amino Acid Sequence↗

PubMed2002

The complete genome sequence of Perina nuda picorna-like virus, an insect-infecting RNA virus with a genome organization similar to that of the mammalian picornaviruses.

Perina nuda picorna-like virus (PnPV) is an insect-infecting RNA virus with morphological and physicochemical characters similar to the Picornaviridae. In this article, we determine the complete genome sequence and analyze the gene organization of PnPV. The genome of PnPV consists of 9476 nucleotides (nts) excluding the poly(A) tail and contains a single large open reading frame (ORF) of 8958 nts (2986 codons) flanked by 473 and 45 nt noncoding regions on the 5' and 3' ends, respectively. Northern blotting did not detect the presence of any subgenomic RNA. The PnPV genome codes for four structural proteins (CP1-4), and determination of their N-terminal sequences by Edman degradation, showed that all four are located in the 5' region of the genome. The 3' part of the PnPV genome contains the consensus sequence motifs for picornavirus RNA helicase, cysteine protease, and RNA-dependent RNA polymerase (RdRp) in that order from the 5' to the 3' end. In all of these characters, the genome organization of PnPV resembles the mammalian picornaviruses and two other insect picorna-like viruses, infectious flacherie virus (IFV) of the silkworm and Sacbrood virus (SBV) of the honeybee. In a phylogenetic tree based on the eight conserved domains in the RdRp sequence, PnPV formed a separate cluster with IFV and SBV, which suggests that these three insect picorna-like viruses might constitute a novel group of insect-infecting RNA viruses.

Amino Acid Sequence↗

PubMed2002

Identification of a nucleocapsid protein (VP35) gene of shrimp white spot syndrome virus and characterization of the motif important for targeting VP35 to the nuclei of transfected insect cells.

To identify the protein encoded by a 687-bp open reading frame (ORF) of a salI genomic DNA fragment of shrimp white spot syndrome virus (WSSV), we expressed the ORF in a baculovirus/insect cell expression system. The apparent molecular mass of the recombinant protein on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) was 35 kDa in insect cells. Antibody raised against bacterially synthesized protein of the ORF identified a nucleocapsid protein (VP35) in the extracts of both the purified WSSV virions and the nucleocapsids which comigrated with the 35-kDa baculovirus-expressed recombinant protein on SDS-PAGE. We also show by transient expression in insect cells (Sf9) that VP35 targets the nucleus. Two potential nuclear localization signals (NLSs) were characterized, but only one of them was important for targeting VP35 to the nuclei of transfected insect cells. Replacement of a cluster of four positively charged residues ((24)KRKR(27)) at the N terminus of the protein with AAAA resulted in mutant proteins that were distributed only in the cytoplasm, thus confirming that this sequence is a critical part of the functionally active NLS of VP35.

Amino Acid Sequence↗

PubMed2002

Gene expression of Na+-K+-ATPase alpha 1 and alpha 3 subunits in gills of the teleost Oreochromis mossambicus, adapted to different environmental salinities.

The objective of the present study was to test the hypothesis that fish gills can express more than one isoform of the Na+-K+-ATPase a subunit responsible for ion regulation in seawater and freshwater environments. Using rapid amplification of complementary DNA ends (RACE), we cloned and sequenced full-length cDNAs encoding Na+-K+-ATPase alpha 1 and alpha 3 subunits of tilapia (Oreochromis mossambicus). Clone TG33 is 3390 bp in length and encodes a polypeptide of 1023 amino acids, while clone TH3 is 3581 bp in length and encodes a protein of 1010 amino acids. Clones TG33 and TH3 showed 91% and 88% identities at the amino acid level with previously described animal Na+-K+-ATPase alpha 1 and alpha 3 subunits, respectively. Northern blot and reverse transcriptase polymerase chain reaction analyses indicated that the alpha 1 subunit is expressed predominantly in kidney and intestine, while the alpha 3 subunit is expressed mainly in brain and heart. However, lower levels of expression of both genes were detected in other tissues such as gill, spleen, and testis. The amounts of both alpha 1 and alpha 3 subunit messenger RNA in gill tissue increased with the level of environmental salinity. This provides direct evidence of enhanced transcription of N+-K+-ATPase alpha 1 and alpha 3 subunit genes upon salinity challenge.

Journal Article↗

PubMed2002

Alteration of trace element distribution and testis ACE activity in mice with high peritoneal aluminum.

The present investigation was conducted to assess the effects of subacute aluminum (Al) exposure on testicular zinc (Zn), copper (Cu), and iron (Fe) distribution in mice. Animals were intraperitoneally exposed to 0, 13, or 35 mg Al/kg body weight/d for a period of 14 d. Al concentrations in serum and testis in Al-treated animals were significantly higher than those of controls. The serum concentrations of Fe were lower, whereas serum Zn and Cu showed a pattern comparable to that of controls. The accumulation of testicular Fe and Cu remarkably increased in Al-exposed groups, whereas the Zn concentration in testis was significantly reduced only at the highest dose of Al exposure. The values of testicular thiobarbituric acid reactive substances (TBARS) were also increased after Al administration, indicating increased lipid peroxidation and oxidative stress. In addition, when the testicular Al was increased, the testis-specific angiotensin-converting enzyme (testis ACE) was noted. The results of this study indicated that part of the effect of Al intoxication on testis might contribute to abnormal metabolism of other minerals, such as Fe, Zn, and/or Cu. It was also suggested that reduced testis ACE activity presumably plays an important role in oxidative damage of Al-induced testicular toxicity.

Aluminum↗

PubMedDate not supplied

Early detection of antibodies against various structural proteins of the SARS-associated coronavirus in SARS patients.

Severe acute respiratory syndrome (SARS), a new disease with symptoms similar to those of atypical pneumonia, raised a global alert in March 2003. Because of its relatively high transmissibility and mortality upon infection, probable SARS patients were quarantined and treated with special and intensive care. Therefore, instant and accurate laboratory confirmation of SARS-associated coronavirus (SARS-CoV) infection has become a worldwide interest. For this need, we purified recombinant proteins including the nucleocapsid (N), envelope (E), membrane (M), and truncated forms of the spike protein (S1-S7) of SARS-CoV in Escherichia coli. The six proteins N, E, M, S2, S5, and S6 were used for Western blotting (WB) to detect various immunoglobulin classes in 90 serum samples from 54 probable SARS patients. The results indicated that N was recognized in most of the sera. In some cases, S6 could be recognized as early as 2 or 3 days after illness onset, while S5 was recognized at a later stage. Furthermore, the result of recombinant-protein-based WB showed a 90% agreement with that of the whole-virus-based immunofluorescence assay. Combining WB with existing RT-PCR, the laboratory confirmation for SARS-CoV infection was greatly enhanced by 24.1%, from 48.1% (RT-PCR alone) to 72.2%. Finally, our results show that IgA antibodies against SARS-CoV can be detected within 1 week after illness onset in a few SARS patients.

Animals↗