Papers by michiyuki yamada
Biochemical Society Transactions, Oct 1, 2000
Journal of Virology, May 1, 1978
DNA synthesis in chromatin isolated from herpes simplex virus type 1-infected HeLa cells (HSV chr... more DNA synthesis in chromatin isolated from herpes simplex virus type 1-infected HeLa cells (HSV chromatin) was examined in vitro. The HSV chromatin. was found to carry out an initial limited synthesis of DNA in vitro, 50 to 64 pmol of dTMP incorporated in 106 nuclei per 10 min, which is comparable to that found in nuclei isolated from HSV-infected cells. DNA synthesis in vitro proceeded for only 30 min, and both HSV DNA and host DNA were synthesized in significant amounts. The HSV and host DNA syntheses in isolated chromatin were inhibited to the same extent by anti-HSV antiserum or by phosphonoacetic acid. The results indicate that the HSV-induced DNA polymerase is most likely involved in the synthesis of host and HSV DNA in isolated chromatin, even though this chromatin contains small amounts of the host-y-polymerase in addition to the HSV-induced DNA polymerase. The HSV chromatin contains no detectable levels of DNA polymerases a and f, even though infected cells have normal, or increased, levels of these enzymes. Nuclei isolated from uninfected and virus-in-chromatin preparation isolated from the nuclei fected eucaryotic cells have been used to study of HSV-infected HeLa cells can also replicate in vitro DNA replication. It has been demon-both HSV and host DNA and that the HSVstrated that DNA synthesis by isolated nuclei induced DNA polymerase is responsible for both requires deoxynucleotides, ATP, and cytoplas-the HSV DNA and the host DNA syntheses in mic fraction (see review [10]). Although DNA this system. synthesis by isolated nuclei produces some abnormal distribution of DNA sequences (32), the MATERIALS AND METHODS nuclei system has been used successfully to de-Radiochemicals. [Methyl-3H]dTTP was purtect stimulatory factors in the cytoplasm (4, 11) chased from Schwarz/Mann, and [methyl-3H]thymiand to show the involvement of RNA in DNA dine, [a-3P]dTTP and [5-'5I]dCTP were obtained replication (22, 23, 27, 28, 31). from New England Nuclear Corp. Recently, the extraction and reconstitution of Chemicals. Deoxynucleoside triphosphates and rinuclear DNA synthesis in isolated mammalian bonucleoside triphosphates were purchased from Sigma Chemical Co. Bromodeoxyuridine triphosphate cell nucei has been attempted (26), and parteal was obtained from P-L Biochemicals, and Sarkosyl separation of a putative adenovirus DNA repli-NL-97 was from the Ciba-Geigy Corp. Phosphonoacecation complex from adenovirus-infected nuclei tic acid was a gift of E. Heimer and A. Cook from the (33) has been suggested. The finding that simian Hoffman-La Roche Research Laboratories. Pancreatic virus 40 DNA synthesis can occur in a nucleo-DNase I and RNase were from Worthington Biochemprotein complex (9, 25) and that HeLa DNA ical Corp., and RNase Ti and Pronase were from synthesis is observed in isolated chromatin (12) Calbiochem. HSV antiserum was the same as dehas shown that chromatin is active for DNA scribed previously (7). Ethyleneglycol-bis(fi-aminosynthesis in vitro. Chromatin may offer advan-ethyl ether)-NN-tetraacetic acid (EGTA) was obtages over the isolad ntained from Sigma Chemical Co. tages over the Isolated nuclei in itS accessiblity Cell culture and virus infection. HeLa F cells to DNA polymerases or other enzymatic factors were used for the proliferation of HSV type 1 (HSV-1) (12,15). (Miyama strain) (20). HeLa F cells were grown in Previously, a number of groups have reported monolayer culture in a glass roller bottle (10 by 50 cm) that nuclei from herpes simplex virus (HSV)or in 150-cm2 culture flasks with F-li medium (Grand infected cells could synthesize HSV DNA in Island Biological Co.) supplemented with 10% fetal vitro (2, 6, 7, 14). This paper will show that a calf serum, 4 mM glutamine, and 1% streptomycinpenicillin. When the cells approached confluency, they
Journal of Biochemistry, 1968
Peptide science : proceedings of the ... Japanese Peptide Symposium, Mar 1, 2005
Annotationes zoologicae Japonenses, Mar 10, 1964
Biochemical Society Transactions, Oct 1, 2000
HnRNPs are nuclear RNA-and DNA-binding proteins and function in nuclear mRNA biogenesis and cytop... more HnRNPs are nuclear RNA-and DNA-binding proteins and function in nuclear mRNA biogenesis and cytoplamic mRNA metabolism. We have isolated to characterize a hnRNP D-like protein JKTBP by DNA affinity screening using an intron 9 sequence of the myeloperoxidase gene as a probe. JKTBP has two RNA binding domains (RBD) arranged in tandem and is closely related to hnRNP D/AUFl. There are two major isoforms of JKTBP-1 and-2 and three minor isoforms. Recombinant JKTBPl binds to poly (A)+RNA. The two RBDs are required for the sequence-specific binding, and in addition the C-terminal region is required for higher affinity binding. JKTBP is an abundant nuclear protein. Inhibitions of RNA synthesis by actinomycin D and RNA pol I1 inhibitor DRB cause a cytoplasmic accumulation of JKTBP-1 but not JKTBP-2. EGFP-labeled JKTBPl previously located in the HeLa nucleus migrated into the mouse nucleus in heterokaryons, suggesting nuclear-cytoplasmic shuttling of JKTBP1. An UV-cross linking experiment indicated that poly (A)+RNA-JKTBPI complex is found in the cytoplasm upon actinomycin D treatment, but not in the nucleus. These findings suggest that JKTBPl associates with mRNA to export it from the nucleus and itself returns to the nucleus.
Biochemical and Biophysical Research Communications, Oct 1, 1979
Japanese Journal of Pharmacology, 2000
Journal of Biochemistry, 1975
Histone methylation plays key roles in the regulation of chromatin structure and function. The re... more Histone methylation plays key roles in the regulation of chromatin structure and function. The recent identification of enzymes that antagonize or remove histone methylation offers new opportunities to appreciate histone methylation plasticity in the regulation of epigenetic pathways. Peptidylarginine deiminase 4 (PADI4) was the first enzyme shown to antagonize histone methylation. PADI4 functions as a histone deiminase converting a methylarginine residue to citrulline at specific sites on the tail of histones H3 and H4. This activity is linked to repression of the estrogen-regulated pS2 promoter. Very little is known as to how PADI4 silences gene expression. To investigate the mechanisms by which histone demethylation and in particular PADI4 functions, and as no PADI4 interactors have been described so far, in vitro interaction assays and coimmunoprecipitations were performed. We found that the histone deacetylase HDAC1 interacts with PADI4, both in vitro and in vivo, and associate...
Japanese Journal of Pharmacology, 2000
The Journal of Biochemistry, 1968
The Journal of Biochemistry, 1969
The FEBS Journal, 2005
Heterogeneous nuclear ribonucleoprotein (hnRNP) D/AUF1 functions in mRNA genesis in the nucleus a... more Heterogeneous nuclear ribonucleoprotein (hnRNP) D/AUF1 functions in mRNA genesis in the nucleus and modulates mRNA decay in the cytoplasm. Although it is primarily nuclear, it shuttles between the nucleus and cytoplasm. We studied the nuclear import and export of the last exon‐encoding sequence common to all its isoforms by its expression as a green fluorescent protein‐fusion protein in HeLa cells and by heterokaryon assay. The C‐terminal 19‐residue sequence (SGYGKVSRRGGHQNSYKPY) was identified as an hnRNP D nucleocytoplasmic shuttling sequence (DNS). In vitro nuclear transport using permeabilized cells indicated that nuclear import of DNS is mediated by transportin‐1 (Trn‐1). DNS accumulation in the nucleus was dependent on Trn‐1, Ran, and energy in multiple rounds of nuclear transport. Use of DNS with deletions, alanine scanning mutagenesis and point mutations revealed that two separate regions (the N‐terminal seven residues and the C‐terminal two residues) are crucial for in vivo...
Nucleic Acids Research, 1978
The effects of various polyanions including synthetic polynucleotides on DNA polymerases-a and.-a... more The effects of various polyanions including synthetic polynucleotides on DNA polymerases-a and.-a from blastulae of the sea urchin Hemicentrotus pulcherrimus and HeLa cells were studied. Only DNA polymerase-a was inhibited by polyanions, such as polyvinyl sulfate, dextran sulfate, heparin, poly(G), poly(I), poly(U) and poly(ADP-Rib). Of the various polynucleotides tested, poly(G) and poly(I) were the strongest inhibitors. Kinetic studies showed that the Ki value for poly(G) was 0.3 pg/ml and that poly(G) had 20-fold higher affinity than activated DNA for the template-primer site of DNA polymerase-a. Poly(U) and poly(ADP-Rib) were also inhibitory, but they were one hundredth as inhibitory as poly(G) or poly(I). Poly(A), poly(C), poly(A)-poly(U) and poly(I).poly(C) were not inhibitory to DNA polymerase-a. In contrast, DNA polymerase-a was not affected at all by these polyanions under the same conditions.
Neuroscience, 2004
It has been implicated that glia activation plays a critical role in the progression of Alzheimer... more It has been implicated that glia activation plays a critical role in the progression of Alzheimer's disease (AD). However, the precise mechanism of glia activation is not clearly understood yet. In our present studies, we confirmed our previous results where change the levels of neuropeptides and peptidases in ibotenic acid (IBO) infusion into the rat nucleus basalis magnocellularis, an animal model of AD. Furthermore, we extended our study to investigate a possible protection effect of co-administration on the changes of neuropeptides, and neuronal and glial cells in IBO-infused rat brain by memantine treatment. The levels of substance P and somatostatin were decreased in the striatum and frontal cortex 1 week after IBO infusion, and recovered to the control level by memantine treatment, indicating the involvement of neuropeptides in AD pathology. Furthermore, the immunohistochemical and enzymatic studies of GFAP and CD 11b, and peptidylarginine deiminase, markers of glia, in the striatum and frontal cortex showed the increase in IBO-treated rat brain as compared with controls, while co-administration of memantine and IBO no increase of astrocytes and microglia activation was observed. The present biochemical and immunohistochemical results suggest that glia activation might play an important role to the pathology of AD, and correlate with the changes of neuropeptide levels in AD brain that is recovered by memantine treatment.
Leukemia Research, 1992
The catalase activities of HP50-2 and HP100-1 cells, which are H2Oe-resistant cell lines derived ... more The catalase activities of HP50-2 and HP100-1 cells, which are H2Oe-resistant cell lines derived from human leukemia HL-60 cells, were 3 and 18 times higher, respectively, than that of HL-60 cells. These catalase activities of the resistant cells were precipitated with anti-catalase serum. The glutathione peroxidase activity of HP50-2 cells was about twice that of HL-60 or HP100-1 cells. The superoxide dismutase activities of HP50-2 and HP100-1 cells were, respectively, about 4 and 2 times that of HL-60 cells. In addition, both the resistant cell lines were completely devoid of myeloperoxidase activity. Pulse-labeling experiments showed that the syntheses of catalase in HP50-2 and HP100-1 cells were, respectively, 2 and 4 times that in HL-60 cells, and that, unlike the parent cells, neither line synthesized myeloperoxidase. Thus the alteration of catalase, glutathione peroxidase, and superoxide dismutase activity could be linked to the resistance to H202 of human leukemia cells.
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Papers by michiyuki yamada