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101.
Lu WW Hsu YY Yang JY Kung SH 《Biochemical and biophysical research communications》2004,325(2):494-499
102.
Sequence analysis within the unique long segment of the bovine herpesvirus 1 (BHV-1) genome previously identified an open reading frame (ORF), designated UL2, whose deduced polypeptide of 204 amino acids contained a consensus uracil-DNA glycosylase (UDGase) signature sequence. To determine whether the BHV-1 UL2 ORF product has UDGase activity, we positioned the UL2 sequence downstream of the T7 promoter on the vector pET-28b(+) and expressed it in Escherichia coli. Upon induction with isopropyl β-D -thiogalactopyranoside these cells produced a 23-kDa protein, the molecular mass of which was in accordance with the prediction from the nucleotide sequence. A one-step purification procedure using nickel-chelating affinity chromatography resulted in a homogeneous preparation of this protein, which displayed specific UDGase activity in an in vitro enzyme assay. These results provide evidence that the BHV-1 UL2 gene does encode a UDGase. 相似文献
103.
Protein kinase A-mediated serine 35 phosphorylation dissociates histone H1.4 from mitotic chromosome
Chu CS Hsu PH Lo PW Scheer E Tora L Tsai HJ Tsai MD Juan LJ 《The Journal of biological chemistry》2011,286(41):35843-35851
Global histone H1 phosphorylation correlates with cell cycle progression. However, the function of site-specific H1 variant phosphorylation remains unclear. Our mass spectrometry analysis revealed a novel N-terminal phosphorylation of the major H1 variant H1.4 at serine 35 (H1.4S35ph), which accumulates at mitosis immediately after H3 phosphorylation at serine 10. Protein kinase A (PKA) was found to be a kinase for H1.4S35. Importantly, Ser-35-phosphorylated H1.4 dissociates from mitotic chromatin. Moreover, H1.4S35A substitution mutant cannot efficiently rescue the mitotic defect following H1.4 depletion, and inhibition of PKA activity increases the mitotic chromatin compaction depending on H1.4. Our results not only indicate that PKA-mediated H1.4S35 phosphorylation dissociates H1.4 from mitotic chromatin but also suggest that this phosphorylation is necessary for specific mitotic functions. 相似文献
104.
Tu S Bulloch EM Yang L Ren C Huang WC Hsu PH Chen CH Liao CL Yu HM Lo WS Freitas MA Tsai MD 《The Journal of biological chemistry》2007,282(19):14262-14271
Based on the prediction that histone lysine demethylases may contain the JmjC domain, we examined the methylation patterns of five knock-out strains (ecm5Delta, gis1Delta, rph1Delta, jhd1Delta, and jhd2Delta (yjr119cDelta)) of Saccharomyces cerevisiae. Mass spectrometry (MS) analyses of histone H3 showed increased modifications in all mutants except ecm5Delta. High-resolution MS was used to unequivocally differentiate trimethylation from acetylation in various tryptic fragments. The relative abundance of specific fragments indicated that histones K36me3 and K4me3 accumulate in rph1Delta and jhd2Delta strains, respectively, whereas both histone K36me2 and K36me accumulate in gis1Delta and jhd1Delta strains. Analyses performed with strains overexpressing the JmjC proteins yielded changes in methylation patterns that were the reverse of those obtained in the complementary knock-out strains. In vitro enzymatic assays confirmed that the JmjC domain of Rph1 specifically demethylates K36me3 primarily and K36me2 secondarily. Overexpression of RPH1 generated a growth defect in response to UV irradiation. The demethylase activity of Rph1 is responsible for the phenotype. Collectively, in addition to Jhd1, our results identified three novel JmjC domain-containing histone demethylases and their sites of action in budding yeast S. cerevisiae. Furthermore, the methodology described here will be useful for identifying histone demethylases and their target sites in other organisms. 相似文献
105.
Hsu EC Lin YC Hung CS Huang CJ Lee MY Yang SC Ting LP 《Journal of biomedical science》2007,14(6):731-744
Summary Protein-tyrosine phosphatase PTPN3 is a membrane-associated non-receptor protein-tyrosine phosphatase. PTPN3 contains a N-terminal
FERM domain, a middle PDZ domain, and a C-terminal phosphatase domain. Upon co-expression of PTPN3, the level of human hepatitis
B viral (HBV) RNAs, 3.5 kb, 2.4/2.1 kb, and 0.7 kb transcribed from a replicating HBV expression plasmid is significantly
reduced in human hepatoma HuH-7 cells. When the expression of endogenous PTPN3 protein is diminished by specific small interfering
RNA, the expression of HBV genes is enhanced, indicating that the endogenous PTPN3 indeed plays a suppressive role on HBV
gene expression. PTPN3 can interact with HBV core protein. The interaction is mediated via the PDZ domain of PTPN3 and the
carboxyl-terminal last four amino acids of core. Either deletion of PDZ domain of PTPN3 or substitution of PDZ ligand in core
has no effect on PTPN3-mediated suppression. These results clearly show that the interaction of PTPN3 with core is not required
for PTPN3 suppressive effect. Mutation of 359serine and 835serine of 14-3-3β binding sites to alanine, which slightly reduces the interaction with 14-3-3β, does not influence the PTPN3
effect. In contrast, mutation of the invariant 842cysteine residue in phosphatase domain to serine, which makes the phosphatase activity inactive, does not change its subcellular
localization and interaction with core or 14-3-3β, but completely abolishes PTPN3-mediated suppression. Furthermore, deletion
of FERM domain does not affect the phosphatase activity or interaction with 14-3-3β, but changes the subcellular localization
from cytoskeleton-membrane interface to cytoplasm and nucleus, abolishes binding to core, and diminishes the PTPN3 effect
on HBV gene expression. Taken together, these results demonstrate that the phosphatase activity and FERM domain of PTPN3 are
essential for its suppression of HBV gene expression.
En-Chi Hsu, Yen-Cheng Lin have equal contributions to this work. 相似文献
106.
107.
108.
Carl PC Chen Chih-Chin Hsu Wen-Lin Yeh Hsiu-Chu Lin Sen-Yung Hsieh Shih-Cherng Lin Tai-Tzung Chen Max JL Chen Simon FT Tang 《Proteome science》2011,9(1):1-10
Background
Prenatal screening for Down Syndrome (DS) would benefit from an increased number of biomarkers to improve sensitivity and specificity. Improving sensitivity and specificity would decrease the need for potentially risky invasive diagnostic procedures.Results
We have performed an in depth two-dimensional difference gel electrophoresis (2D DIGE) study to identify potential biomarkers. We have used maternal plasma samples obtained from first and second trimesters from mothers carrying DS affected fetuses compared with mothers carrying normal fetuses. Plasma samples were albumin/IgG depleted and expanded pH ranges of pH 4.5 - 5.5, pH 5.3 - 6.5 and pH 6 - 9 were used for two-dimensional gel electrophoresis (2DE). We found no differentially expressed proteins in the first trimester between the two groups. Significant up-regulation of ceruloplasmin, inter-alpha-trypsin inhibitor heavy chain H4, complement proteins C1s subcomponent, C4-A, C5, and C9 and kininogen 1 were detected in the second trimester in maternal plasma samples where a DS affected fetus was being carried. However, ceruloplasmin could not be confirmed as being consistently up-regulated in DS affected pregnancies by Western blotting.Conclusions
Despite the in depth 2DE approach used in this study the results underline the deficiencies of gel-based proteomics for detection of plasma biomarkers. Gel-free approaches may be more productive to increase the number of plasma biomarkers for DS for non-invasive prenatal screening and diagnosis. 相似文献109.
M Jadot L Lin D E Sleat I Sohar M S Hsu J Pintar F Dubois S Wattiaux-De Coninck R Wattiaux P Lobel 《The Journal of biological chemistry》1999,274(30):21104-21113
The intracellular transport of soluble lysosomal enzymes relies on the post-translational modification of N-linked oligosaccharides to generate mannose 6-phosphate (Man 6-P) residues. In most cell types the Man 6-P signal is rapidly removed after targeting of the precursor proteins from the Golgi to lysosomes via interactions with Man 6-phosphate receptors. However, in brain, the steady state proportion of lysosomal enzymes containing Man 6-P is considerably higher than in other tissues. As a first step toward understanding the mechanism and biological significance of this observation, we analyzed the subcellular localization of the rat brain Man 6-P glycoproteins by combining biochemical and morphological approaches. The brain Man 6-P glycoproteins are predominantly localized in neuronal lysosomes with no evidence for a steady state localization in nonlysosomal or prelysosomal compartments. This contrasts with the clear endosome-like localization of the low steady state proportion of mannose-6-phosphorylated lysosomal enzymes in liver. It therefore seems likely that the observed high percentage of phosphorylated species in brain is a consequence of the accumulation of lysosomal enzymes in a neuronal lysosome that does not fully dephosphorylate the Man 6-P moieties. 相似文献
110.
Kuruma shrimp Marsupenaeus japonicus held in 34 per thousand seawater were injected with tryptic soy broth (TSB)-grown Vibrio alginolyticus (2.7x10(6)cfu shrimp(-1)), and then placed in water containing concentrations of sulfide at 0 (control), 51, 106, 528 and 1050microgl(-1), respectively. After 12-144h, mortality of V. alginolyticus-injected shrimp exposed to 528 and 1102microgl(-1) sulfide was significantly higher than that of shrimp exposed to 51microgl(-1) sulfide and the control solution. In another experiment, M. japonicus which had been exposed to 0, 56, 112, 525 and 1076microgl(-1) sulfide for 6, 12, 24 and 48h were examined for immune parameters, and phagocytic activity and clearance efficiency of V. alginolyticus. Sulfide concentrations at 525microgl(-1) or greater for 12h resulted in decreased total haemocyte count (THC) and phenoloxidase activity, phagocytic activity and bacterial clearance efficiency, whereas a sulfide concentration at 1076microgl(-1) for 24h caused a significant increase in respiratory burst and superoxide dismutase activity of M. japonicus. It is concluded that concentrations of sulfide at 528microgl(-1) or greater increased the susceptibility of M. japonicus against V. alginolyticus infection by a depression in immune ability. The increased production of superoxide anion by M. japonicus exposed to 525microgl(-1) sulfide or greater was considered to be cytotoxic to the host. 相似文献