H. Yoshikura

Homology-associated nonhomologous recombination in mammalian gene targeting.

Sakagami, K, Tokinaga, Y, Yoshikura, H, Kobayashi, I

Nonhomologous (illegitimate) recombination of DNA underlies many changes in the genome. It involves no or little homology between recombining DNAs and has been considered unrelated with homologous...

Correlation between the infectivity of hepatitis C virus in vivo and its infectivity in vitro.

Shimizu, Y K, Purcell, R H, Yoshikura, H

A murine retrovirus-infected human T-cell line, HPB-Ma, supported replication of hepatitis C virus (HCV) at least as well as the previously reported Molt4-Ma cells. Cloning of HPB-Ma cells revealed a...

Evidence for in vitro replication of hepatitis C virus genome in a human T-cell line.

Shimizu, Y K, Iwamoto, A, Hijikata, M, Purcell, R H, Yoshikura, H

A human T-cell line, MOLT-4, either uninfected or infected with murine retroviruses, was tested for its susceptibility to hepatitis C virus (HCV) infection. The cell cultures were inoculated with a...

Nonconservative recombination in Escherichia coli.

Takahashi, N K, Yamamoto, K, Kitamura, Y, Luo, S Q, Yoshikura, H, Kobayashi, I

Homologous recombination between two duplex DNA molecules might result in two duplex DNA molecules (conservative) or, alternatively, it might result in only one recombinant duplex DNA molecule...

cis Elements Required for High-Level Expression of Unspliced gag-Containing Message in Moloney Murine Leukemia Virus

Oshima, M., Odawara, T., Hanaki, K., Igarashi, H., Yoshikura, H.

The 441-nucleotide (nt) region (nt 5325 to 5766) around the splice acceptor (SA) site (nt 5491) was found to be necessary for high-level expression of gag-containing unspliced RNA of Moloney murine...

Possible role of splice acceptor site in expression of unspliced gag-containing message of Moloney murine leukemia virus.

Oshima, M, Odawara, T, Matano, T, Sakahira, H, Kuchino, Y, Iwamoto, A, ...

Moloney murine leukemia virus (MLV) having the gag coding region alone, G3.6, produced a low level of mRNA (1/10 of the wild-type level). Ligation of 441 nucleotides (nt) containing a splice acceptor...

Characterization of long-term cultures of hepatitis C virus.

Nakajima, N, Hijikata, M, Yoshikura, H, Shimizu, Y K

The human T- and B-cell lines HPBMa10-2 and Daudi produced infectious hepatitis C virus (HCV) for more than 1 year after infection. The infectivity titer of the cell culture-grown HCV and its genome...

Sequence analysis of the hepatitis C virus genome recovered from serum, liver, and peripheral blood mononuclear cells of infected chimpanzees.

Shimizu, Y K, Igarashi, H, Kanematu, T, Fujiwara, K, Wong, D C, Purcell, R H, ...

Of 13 different strains of hepatitis C virus (HCV) in the inoculum used, only 1 persisted in human lymphocyte cell lines infected in vitro (N. Nakajima, M. Hijikata, H. Yoshikura, and Y. K. Shimizu,...

Genetic analysis of double-strand break repair in Escherichia coli.

Takahashi, N K, Kusano, K, Yokochi, T, Kitamura, Y, Yoshikura, H, Kobayashi, I

We had reported that a double-strand gap (ca. 300 bp long) in a duplex DNA is repaired through gene conversion copying a homologous duplex in a recB21 recC22 sbcA23 strain of Escherichia coli, as...

Neutralizing antibodies against hepatitis C virus and the emergence of neutralization escape mutant viruses.

Shimizu, Y K, Hijikata, M, Iwamoto, A, Alter, H J, Purcell, R H, Yoshikura, H

We developed an in vitro assay for antibodies to hepatitis C virus (HCV) that bind to virions and prevent initiation of the replication cycle in susceptible cells in vitro. These antibodies therefore...

Interaction between the dominant negative mutant and the wild-type envelope proteins of Friend murine leukemia virus.

Matano, T, Odawara, T, Ohshima, M, Iwamoto, A, Yoshikura, H

Interaction between the previously obtained dominant negative mutant, referred to as fcr (T. Matano, T. Odawara, M. Ohshima, H. Yoshikura, and A. Iwamoto, J. Virol. 67:2026-2033, 1993), and the...

Multicycle infection of hepatitis C virus in cell culture and inhibition by alpha and beta interferons.

Shimizu, Y K, Yoshikura, H

We previously reported that a clone of a human lymphocytic cell line, HPBMa clone 10-2, supports the genome replication of hepatitis C virus (HCV). In the present study, the multicycle transmission...

Equilibrium centrifugation studies of hepatitis C virus: evidence for circulating immune complexes.

Hijikata, M, Shimizu, Y K, Kato, H, Iwamoto, A, Shih, J W, Alter, H J, ...

The buoyant density of hepatitis C virus (HCV), with high in vivo infectivity (strain H) or low in vivo infectivity (strain F), was determined by sucrose gradient equilibrium centrifugation. Viral...

trans-dominant interference with virus infection at two different stages by a mutant envelope protein of Friend murine leukemia virus.

Matano, T, Odawara, T, Ohshima, M, Yoshikura, H, Iwamoto, A

A dominant negative mutant Friend murine leukemia virus (FMLV) env gene was cloned from an immunoselected Friend erythroleukemia cell. The mutant env had a point mutation which resulted in a...

Construction and characterization of the recombinant Moloney murine leukemia viruses bearing the mouse Fv-4 env gene.

Masuda, M, Yoshikura, H

A nucleotide sequence of the mouse Fv-4 env gene was completed. Structural comparison revealed a close relationship of Fv-4 to the ecotropic Cas-Br-E murine leukemia virus isolated from a wild mouse...

Analysis of Moloney murine leukemia virus revertants mutated at the gag-pol junction.

Odawara, T, Yoshikura, H, Ohshima, M, Tanaka, T, Jones, D S, Nemoto, F, ...

Among Moloney murine leukemia viruses (Mo-MuLVs) having stop codons other than UAG at the gag-pol junction, Mo-MuLV with UAA, but not with UGA, had a replication disadvantage. Mo-MuLV with a...

Frequent partial deletion of human adult T-cell leukemia virus type I proviruses in experimental transmission: pattern and possible implication.

Hiramatsu, K, Yoshikura, H

Human T-cell leukemia virus type I (HTLV I) propagated in human diploid fibroblast IMR90 was transmitted to human promyelocytic leukemia HL60 cells by coculture. Of 14 provirus-positive HL60 clones,...

Characterization of N-type and dually permissive cells segregated from mouse fibroblasts whose Fv-1 phenotype could be modified by another independently segregating gene(s).

Yoshikura, H, Tejima, S, Kuchino, T, Segawa, K, Odaka, T

Though the inbred DDD mouse strain is essentially of the N type, the primary culture of this strain was about 100-fold more sensitive to B-tropic WN1802B virus than were the typical N-type strains...

Analysis of spleen focus-forming virus-specific RNA sequences coding for spleen focus-forming virus-specific glycoprotein with a molecular weight of 55,000 (gp55).

Yoshida, M, Yoshikura, H

The 32S RNA of the Friend strain of spleen focus-forming virus (SFFV) contains two sets of sequences: about half is specific to SFFV, and the other half is in common with the sequence of the helper...

The effect of specific mutations at and around the gag-pol gene junction of Moloney murine leukaemia virus.

Jones, D S, Nemoto, F, Kuchino, Y, Masuda, M, Yoshikura, H, Nishimura, S

By carrying out oligonucleotide-directed mutagenesis, in vitro, on a 3.3 kb XhoI-HindIII fragment from Moloney murine leukaemia virus Mo-MuLV proviral DNA, inserted into the phagemid pTZ19R, nine...

Computation of statistical secondary structure of nucleic acids.

Yamamoto, K, Kitamura, Y, Yoshikura, H

This paper presents a computer analysis of statistical secondary structure of nucleic acids. For a given single stranded nucleic acid, we generated "structure map" which included all the annealing...

Relation between genomic and capsid structures in RNA viruses.

Yamamoto, K, Yoshikura, H

We described a new computer program for calculation of RNA secondary structure. Calculation of 20 viral RNAs with this program showed that genomes of the icosahedral capsid viruses had higher folding...

Transcription termination and RNA processing in the 3'-end spacer of mouse ribosomal RNA genes.

Miwa, T, Kominami, R, Yoshikura, H, Sudo, K, Muramatsu, M

The 3' termini of ribosomal RNA precursors from mouse FM3A cultured cells are mapped to eight sites within 625 bp downstream from the 3' terminus of 28 S rRNA. Three additional sites are mapped in...

Unstable resistance of G mouse fibroblasts to ecotropic murine leukemia virus infection.

Yoshikura, H, Naito, Y, Moriwaki, K

G mouse cells were resistant to N- and NB-tropic Friend leukemia viruses and to B-tropic WN 1802B. Though the cells were resistant to focus formation by the Moloney isolate of murine sarcoma virus,...

Endogenous C-Type Virus of a Mouse Cell Line and Its Defectiveness

Yoshikura, H., Hirokawa, Yasuko

MLg cells originating from a newborn ddY mouse began to release C-type virus by treatment with 5-iodo-2′-deoxyuridine (5 μg/ml) for 48 h, or spontaneoulsy after prolonged cultivation. The data...

Envelope proteins of human T-cell leukemia virus: expression in Escherichia coli and its application to studies of env gene functions.

Kiyokawa, T, Yoshikura, H, Hattori, S, Seiki, M, Yoshida, M

The DNA fragments of the 5' and 3' halves of the putative env gene predicted from the DNA sequence of human T-cell leukemia virus (HTLV) provirus were inserted into expression vectors pORF2 and...

DNA double-strand break repair: genetic determinants of flanking crossing-over.

Kusano, K, Sunohara, Y, Takahashi, N, Yoshikura, H, Kobayashi, I

Whether or not homologous interaction of two DNA molecules results in crossing-over of the flanking sequences is an important decision in view of genome organization. Several homologous recombination...

Intracellular Restriction of Ecotropic Murine Leukemia Virus in Rat NRK Cells and Its Abolishment by Adaptation

Yoshikura, H., Yoshida, M.

Ecotropic murine leukemia viruses, both N-tropic FN-2 (purified helper component of Friend leukemia virus) and B-tropic WNB-2 (purified WN1802B BALB/c-derived endogenous virus), were partially...

Homologous Recombination Involving a Large Heterology in Escherichia Coli

Yamamoto, K., Takahashi, N., Yoshikura, H., Kobayashi, I.

Recombination between two different deletion alleles of a gene (neo) for neomycin and kanamycin resistance was studied in an Escherichia coli sbcA(-) recB(-)C(-) strain. The two homologous regions...

Orientation Dependence in Homologous Recombination

Yamamoto, K., Takahashi, N., Fujitani, Y., Yoshikura, H., Kobayashi, I.

Homologous recombination was investigated in Escherichia coli with two plasmids, each carrying the homologous region (two defective neo genes, one with an amino-end deletion and the other with a...

Genetic Recombination through Double-Strand Break Repair: Shift from Two-Progeny Mode to One-Progeny Mode by Heterologous Inserts

Takahashi, N. K., Sakagami, K., Kusano, K., Yamamoto, K., Yoshikura, H., Kobayashi, I.

Double-strand break repair models of genetic recombination propose that a double-strand break is introduced into an otherwise intact DNA and that the break is then repaired by copying a homologous...

The rise in medical care expenditures in Japan, trends in disease patterns: 1977-81.

Kawamura, N, Gotoda, Y, Yoshikura, H

In Japan, the nationwide cost of medical care is increasing rapidly. Analysis of data from the Japanese health insurance system shows that costs are not rising for all diagnoses and that it is...

Homology-associated nonhomologous recombination in mammalian gene targeting.

Sakagami, K, Tokinaga, Y, Yoshikura, H, Kobayashi, I

Nonhomologous (illegitimate) recombination of DNA underlies many changes in the genome. It involves no or little homology between recombining DNAs and has been considered unrelated with homologous...

Correlation between the infectivity of hepatitis C virus in vivo and its infectivity in vitro.

Shimizu, Y K, Purcell, R H, Yoshikura, H

A murine retrovirus-infected human T-cell line, HPB-Ma, supported replication of hepatitis C virus (HCV) at least as well as the previously reported Molt4-Ma cells. Cloning of HPB-Ma cells revealed a...

Evidence for in vitro replication of hepatitis C virus genome in a human T-cell line.

Shimizu, Y K, Iwamoto, A, Hijikata, M, Purcell, R H, Yoshikura, H

A human T-cell line, MOLT-4, either uninfected or infected with murine retroviruses, was tested for its susceptibility to hepatitis C virus (HCV) infection. The cell cultures were inoculated with a...

Nonconservative recombination in Escherichia coli.

Takahashi, N K, Yamamoto, K, Kitamura, Y, Luo, S Q, Yoshikura, H, Kobayashi, I

Homologous recombination between two duplex DNA molecules might result in two duplex DNA molecules (conservative) or, alternatively, it might result in only one recombinant duplex DNA molecule...

cis Elements Required for High-Level Expression of Unspliced gag-Containing Message in Moloney Murine Leukemia Virus

Oshima, M., Odawara, T., Hanaki, K., Igarashi, H., Yoshikura, H.

The 441-nucleotide (nt) region (nt 5325 to 5766) around the splice acceptor (SA) site (nt 5491) was found to be necessary for high-level expression of gag-containing unspliced RNA of Moloney murine...

Possible role of splice acceptor site in expression of unspliced gag-containing message of Moloney murine leukemia virus.

Oshima, M, Odawara, T, Matano, T, Sakahira, H, Kuchino, Y, Iwamoto, A, ...

Moloney murine leukemia virus (MLV) having the gag coding region alone, G3.6, produced a low level of mRNA (1/10 of the wild-type level). Ligation of 441 nucleotides (nt) containing a splice acceptor...

Characterization of long-term cultures of hepatitis C virus.

Nakajima, N, Hijikata, M, Yoshikura, H, Shimizu, Y K

The human T- and B-cell lines HPBMa10-2 and Daudi produced infectious hepatitis C virus (HCV) for more than 1 year after infection. The infectivity titer of the cell culture-grown HCV and its genome...

Sequence analysis of the hepatitis C virus genome recovered from serum, liver, and peripheral blood mononuclear cells of infected chimpanzees.

Shimizu, Y K, Igarashi, H, Kanematu, T, Fujiwara, K, Wong, D C, Purcell, R H, ...

Of 13 different strains of hepatitis C virus (HCV) in the inoculum used, only 1 persisted in human lymphocyte cell lines infected in vitro (N. Nakajima, M. Hijikata, H. Yoshikura, and Y. K. Shimizu,...

Genetic analysis of double-strand break repair in Escherichia coli.

Takahashi, N K, Kusano, K, Yokochi, T, Kitamura, Y, Yoshikura, H, Kobayashi, I

We had reported that a double-strand gap (ca. 300 bp long) in a duplex DNA is repaired through gene conversion copying a homologous duplex in a recB21 recC22 sbcA23 strain of Escherichia coli, as...

Neutralizing antibodies against hepatitis C virus and the emergence of neutralization escape mutant viruses.

Shimizu, Y K, Hijikata, M, Iwamoto, A, Alter, H J, Purcell, R H, Yoshikura, H

We developed an in vitro assay for antibodies to hepatitis C virus (HCV) that bind to virions and prevent initiation of the replication cycle in susceptible cells in vitro. These antibodies therefore...

Interaction between the dominant negative mutant and the wild-type envelope proteins of Friend murine leukemia virus.

Matano, T, Odawara, T, Ohshima, M, Iwamoto, A, Yoshikura, H

Interaction between the previously obtained dominant negative mutant, referred to as fcr (T. Matano, T. Odawara, M. Ohshima, H. Yoshikura, and A. Iwamoto, J. Virol. 67:2026-2033, 1993), and the...

Multicycle infection of hepatitis C virus in cell culture and inhibition by alpha and beta interferons.

Shimizu, Y K, Yoshikura, H

We previously reported that a clone of a human lymphocytic cell line, HPBMa clone 10-2, supports the genome replication of hepatitis C virus (HCV). In the present study, the multicycle transmission...

Equilibrium centrifugation studies of hepatitis C virus: evidence for circulating immune complexes.

Hijikata, M, Shimizu, Y K, Kato, H, Iwamoto, A, Shih, J W, Alter, H J, ...

The buoyant density of hepatitis C virus (HCV), with high in vivo infectivity (strain H) or low in vivo infectivity (strain F), was determined by sucrose gradient equilibrium centrifugation. Viral...

trans-dominant interference with virus infection at two different stages by a mutant envelope protein of Friend murine leukemia virus.

Matano, T, Odawara, T, Ohshima, M, Yoshikura, H, Iwamoto, A

A dominant negative mutant Friend murine leukemia virus (FMLV) env gene was cloned from an immunoselected Friend erythroleukemia cell. The mutant env had a point mutation which resulted in a...

Construction and characterization of the recombinant Moloney murine leukemia viruses bearing the mouse Fv-4 env gene.

Masuda, M, Yoshikura, H

A nucleotide sequence of the mouse Fv-4 env gene was completed. Structural comparison revealed a close relationship of Fv-4 to the ecotropic Cas-Br-E murine leukemia virus isolated from a wild mouse...

Analysis of Moloney murine leukemia virus revertants mutated at the gag-pol junction.

Odawara, T, Yoshikura, H, Ohshima, M, Tanaka, T, Jones, D S, Nemoto, F, ...

Among Moloney murine leukemia viruses (Mo-MuLVs) having stop codons other than UAG at the gag-pol junction, Mo-MuLV with UAA, but not with UGA, had a replication disadvantage. Mo-MuLV with a...

Frequent partial deletion of human adult T-cell leukemia virus type I proviruses in experimental transmission: pattern and possible implication.

Hiramatsu, K, Yoshikura, H

Human T-cell leukemia virus type I (HTLV I) propagated in human diploid fibroblast IMR90 was transmitted to human promyelocytic leukemia HL60 cells by coculture. Of 14 provirus-positive HL60 clones,...

Characterization of N-type and dually permissive cells segregated from mouse fibroblasts whose Fv-1 phenotype could be modified by another independently segregating gene(s).

Yoshikura, H, Tejima, S, Kuchino, T, Segawa, K, Odaka, T

Though the inbred DDD mouse strain is essentially of the N type, the primary culture of this strain was about 100-fold more sensitive to B-tropic WN1802B virus than were the typical N-type strains...

Analysis of spleen focus-forming virus-specific RNA sequences coding for spleen focus-forming virus-specific glycoprotein with a molecular weight of 55,000 (gp55).

Yoshida, M, Yoshikura, H

The 32S RNA of the Friend strain of spleen focus-forming virus (SFFV) contains two sets of sequences: about half is specific to SFFV, and the other half is in common with the sequence of the helper...

The effect of specific mutations at and around the gag-pol gene junction of Moloney murine leukaemia virus.

Jones, D S, Nemoto, F, Kuchino, Y, Masuda, M, Yoshikura, H, Nishimura, S

By carrying out oligonucleotide-directed mutagenesis, in vitro, on a 3.3 kb XhoI-HindIII fragment from Moloney murine leukaemia virus Mo-MuLV proviral DNA, inserted into the phagemid pTZ19R, nine...

Computation of statistical secondary structure of nucleic acids.

Yamamoto, K, Kitamura, Y, Yoshikura, H

This paper presents a computer analysis of statistical secondary structure of nucleic acids. For a given single stranded nucleic acid, we generated "structure map" which included all the annealing...

Relation between genomic and capsid structures in RNA viruses.

Yamamoto, K, Yoshikura, H

We described a new computer program for calculation of RNA secondary structure. Calculation of 20 viral RNAs with this program showed that genomes of the icosahedral capsid viruses had higher folding...

Transcription termination and RNA processing in the 3'-end spacer of mouse ribosomal RNA genes.

Miwa, T, Kominami, R, Yoshikura, H, Sudo, K, Muramatsu, M

The 3' termini of ribosomal RNA precursors from mouse FM3A cultured cells are mapped to eight sites within 625 bp downstream from the 3' terminus of 28 S rRNA. Three additional sites are mapped in...

Unstable resistance of G mouse fibroblasts to ecotropic murine leukemia virus infection.

Yoshikura, H, Naito, Y, Moriwaki, K

G mouse cells were resistant to N- and NB-tropic Friend leukemia viruses and to B-tropic WN 1802B. Though the cells were resistant to focus formation by the Moloney isolate of murine sarcoma virus,...

Endogenous C-Type Virus of a Mouse Cell Line and Its Defectiveness

Yoshikura, H., Hirokawa, Yasuko

MLg cells originating from a newborn ddY mouse began to release C-type virus by treatment with 5-iodo-2′-deoxyuridine (5 μg/ml) for 48 h, or spontaneoulsy after prolonged cultivation. The data...

Envelope proteins of human T-cell leukemia virus: expression in Escherichia coli and its application to studies of env gene functions.

Kiyokawa, T, Yoshikura, H, Hattori, S, Seiki, M, Yoshida, M

The DNA fragments of the 5' and 3' halves of the putative env gene predicted from the DNA sequence of human T-cell leukemia virus (HTLV) provirus were inserted into expression vectors pORF2 and...

DNA double-strand break repair: genetic determinants of flanking crossing-over.

Kusano, K, Sunohara, Y, Takahashi, N, Yoshikura, H, Kobayashi, I

Whether or not homologous interaction of two DNA molecules results in crossing-over of the flanking sequences is an important decision in view of genome organization. Several homologous recombination...

Intracellular Restriction of Ecotropic Murine Leukemia Virus in Rat NRK Cells and Its Abolishment by Adaptation

Yoshikura, H., Yoshida, M.

Ecotropic murine leukemia viruses, both N-tropic FN-2 (purified helper component of Friend leukemia virus) and B-tropic WNB-2 (purified WN1802B BALB/c-derived endogenous virus), were partially...

Homologous Recombination Involving a Large Heterology in Escherichia Coli

Yamamoto, K., Takahashi, N., Yoshikura, H., Kobayashi, I.

Recombination between two different deletion alleles of a gene (neo) for neomycin and kanamycin resistance was studied in an Escherichia coli sbcA(-) recB(-)C(-) strain. The two homologous regions...

Orientation Dependence in Homologous Recombination

Yamamoto, K., Takahashi, N., Fujitani, Y., Yoshikura, H., Kobayashi, I.

Homologous recombination was investigated in Escherichia coli with two plasmids, each carrying the homologous region (two defective neo genes, one with an amino-end deletion and the other with a...

Genetic Recombination through Double-Strand Break Repair: Shift from Two-Progeny Mode to One-Progeny Mode by Heterologous Inserts

Takahashi, N. K., Sakagami, K., Kusano, K., Yamamoto, K., Yoshikura, H., Kobayashi, I.

Double-strand break repair models of genetic recombination propose that a double-strand break is introduced into an otherwise intact DNA and that the break is then repaired by copying a homologous...

The rise in medical care expenditures in Japan, trends in disease patterns: 1977-81.

Kawamura, N, Gotoda, Y, Yoshikura, H

In Japan, the nationwide cost of medical care is increasing rapidly. Analysis of data from the Japanese health insurance system shows that costs are not rising for all diagnoses and that it is...