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M Yanagida

Publications and source records attributed to M Yanagida.

At least 217 records · Page 12Linked to original sources
PubMed1985

Histone gene organization of fission yeast: a common upstream sequence.

Histone genes of the fission yeast Schizosaccharomyces pombe were cloned from Charon 4A and cosmid gene libraries by hybridization, and their nucleotide sequences were determined. The genome of S. pombe has a single, isolated H2A, a pair of H2A-H2B and three pairs of H3-H4 (one H2B, two H2A and three each of H3 and H4). This non-assorted histone gene organization is distinct from that of the budding yeast which has two pairs of H2A-H2B and H3-H4. The predicted amino acid sequences of S. pombe histone H2As, H3s and H4s were identical except for three residue changes in H2As. Compared with those os S. cerevisiae and human, variable residues were clustered near the NH2- and COOH-terminal regions of H2A and H2B. Sequence homologies to the two organisms were roughly the same in H2A (79-83%), H3 (92-93%) and H4 (91%), but differed in H2B (82% to S. cerevisiae and 68% to human). The coding sequences in pairs of S. pombe histone genes were divergently directed. A 17-bp long highly homologous sequence (AACCCT box) that had internal 6-bp direct repeats was present in the intergene spacer sequences or in the 5' upstream region of all the cloned histone genes. A possible regulatory role of the common upstream sequence for histone gene expression is discussed.

Amino Acid Sequence↗
PubMed1985

A cruciform in the direct repeats of the yeast 2 micron DNA: Selective S1 nuclease cleavage at one of the three homologous palindromes.

An S1-hypersensitive site was found at the 60 bp direct repeats of the cis-acting, stability and/or copy number control region of the yeast 2 micron DNA in the supercoiled hybrid plasmid pDB248'. It was retained in a different plasmid, pYK2121, consisting of pBR322 and the 300 bp long repeated DNA. Analyses of 5'-end-labeled fragments and nucleotide sequence determination showed that the S1-cleavage site was at the central part of an AT-rich 19 bp palindrome present in the repeats. Two other homologous palindromes (21 and 15 bp) containing the 12 bp consensus sequences were not cleaved. The nucleotide sequences at the base of the stem and/or loop may determine the efficiency of the cruciform extrusion.

Base Sequence↗
PubMed1984

Isolation of type I and II DNA topoisomerase mutants from fission yeast: single and double mutants show different phenotypes in cell growth and chromatin organization.

We have isolated mutants defective in DNA topoisomerases and an endonuclease from the fission yeast Schizosaccharomyces pombe by screening individual extracts of mutagenized cells. Two type I topoisomerase mutants (top1) and three endonuclease mutants (end1) were all viable. The double mutant top1 end1 was also viable and, in its extract, Mg2+- and ATP- dependent type II activity could be detected. Three temperature-sensitive (ts-) mutants having heat-sensitive (hs-) type II enzymes were isolated, and the ts- marker cosegregated with the hs- type II activity. All the ts- mutations fell in one gene (top2) tightly linked to leul in chromosome II. The nuclear division of single top2 mutants was blocked at the restrictive temperature, but the formation of a septum was not inhibited so that the nucleus was cut across with the cell plate. In contrast, the double top1 top2 mutants were rapidly arrested at various stages of the cell cycle, showing a strikingly altered nuclear chromatin region. The type II topoisomerase may have an essential role in the compaction and/or segregation of chromosomes during the nuclear division but also complement the defect of the type I enzyme whose major function is the maintenance of chromatin organization throughout the cell cycle.

Ascomycota↗
PubMed1984

Molecular organization of the head of bacteriophage Teven: underlying design principles.

Structure and assembly of the bacteriophage T4 head are described as revealed by results obtained in this laboratory. Subunit arrangement of the major coat protein, soc and hoc in the head shell has been determined (Figs. 2 and 21). Two new approaches for studying the assembly pathway are presented: wild type infection at 19 degrees C and gene 23 cold sensitive mutants. We propose an assembly pathway in which the prehead is formed in one direction, starting from the neck and ending at the distal cap. The processes of proximal and distal capping of the head shell are distinctly different. Novel structural intermediates such as a naked core and cup-like particles are shown. A model on head length determination is presented, based on negative control by the core on distal capping. Interesting aspects in the maturation of the head are reviewed. An overall scheme of the head assembly is shown in Fig. 20. Comparative studies among Teven and RB phages showed that the particle morphology is strictly conserved while certain so-called non-essential and essential proteins are significantly varied. A phylogenetic relation among these phages is constructed from calculation of distances (Fig. 25).

Bacterial Proteins↗
PubMed1984

The NDA3 gene of fission yeast encodes beta-tubulin: a cold-sensitive nda3 mutation reversibly blocks spindle formation and chromosome movement in mitosis.

The cells of a cold-sensitive mutant nda3-KM311 of the fission yeast Schizosaccharomyces pombe were arrested highly synchronously at a step similar to mitotic prophase when incubated at a restrictive temperature. DAPI staining and indirect immunofluorescence microscopy showed three condensed chromosomes but no spindle. Six minutes after the temperature shifted to a permissive one, the spindle appeared and elongated. The chromosomes were separated at a constant speed (relative velocity 1 micron/min), and the spindle disappeared after the chromosomes reached opposite ends of the cell. The NDA3 gene of S. pombe was cloned by transformation. The 2.6 kb Hind III genomic DNA that complemented the nda3 mutations had only one coding frame split with five short introns. The predicted amino acid sequence contained 448 residues, and was 75% homologous to that of chicken beta-tubulin.

Amino Acid Sequence↗
PubMed1984

Identification of the pleiotropic cell division cycle gene NDA2 as one of two different alpha-tubulin genes in Schizosaccharomyces pombe.

Mutations in a cell-cycle gene NDA2 of Schizosaccharomyces pombe have pleiotropic effects on nuclear division, nuclear location, and thiabendazole sensitivity ( Toda et al., 1983). By transformation and nucleotide sequence determination, we identified NDA2 as one of two alpha-tubulin genes present in the genome of S. pombe. Two cloned sequences complemented cold-sensitive and thiabendazole-supersensitive nda2 mutations; one was derived from NDA2 that encodes alpha 1-tubulin, the other from an unidentified locus encoding alpha 2-tubulin. The predicted amino acid sequences showed that the alpha 1- and alpha 2-tubulins had respective residues of 455 and 449 (molecular weights 51,200 and 50,600). The homology to porcine alpha-tubulin was 76% in both cases. Frequent alterations took place in the two restricted regions. The alpha 1-tubulin (NDA2) clone had a 90 bp intervening sequence, the alpha 2-tubulin clone did not. RNA blot hybridization experiments indicated that both genes are transcribed. S. pombe tubulin was isolated by cycles of assembly and disassembly. Presumed alpha- and beta-tubulin polypeptide bands reacted with monoclonal antibodies specific for chicken alpha- and beta-tubulins.

Amino Acid Sequence↗
PubMed1984

Effect of late pregnancy on salicylate, diazepam, warfarin, and propranolol binding: use of fluorescent probes.

Serum protein binding was measured in six women 38 wk pregnant and in five control subjects. Three distinct binding sites for drugs on human serum albumin have been identified. To determine whether changes in binding during pregnancy occur for common drugs or only for drugs that bind to a specific binding site, serum protein binding of three drugs--diazepam (site I), warfarin (site III), and salicylate--and four fluorescent probes--dansylsarcosine (site I), 1-anilino-8-naphthalenesulfonate (site I), 7-anilinocoumarin-4-acetic acid (site II), and 5-dimethylaminonaphthalene-1-sulfonamide (DNSA) (site III)--were determined in control and pregnant sera. Unbound fractions of diazepam and salicylate in pregnant women increased but the unbound fraction of warfarin did not change. Dissociation constants (Kd1) of all fluorescent probes but DNSA were almost the same in control and pregnant sera, while the Kd1 of DNSA in pregnant serum was approximately 50% of control. Binding capacities of all probes decreased, which was attributed to decreased serum albumin concentration. We concluded that serum protein binding of drugs that bind to site I or site II on albumin decreased largely because of the reduced serum albumin concentration during pregnancy and that the binding of drugs that bind to site III changed little because of compensating effects of the decrease in serum albumin concentration and the increase in binding affinity to serum albumin. Serum concentration of alpha 1-acid glycoprotein and serum binding of propranolol did not change in pregnant women.

Adult↗
PubMed1984

A meiotic mutant of the fission yeast Schizosaccharomyces pombe that produces mature asci containing two diploid spores.

A mutant of the fission yeast Schizosaccharomyces pombe grew normally in the mitotic cycle but produced two-spored asci in the meiosis cycle. These spores were diploid, and the segregation of centromere-linked markers in the dyads was mostly reductional. Only the first meiotic division appears to occur in this tws1 mutant, resulting in enclosure of diploid nuclei into spores.

Ascomycota↗
PubMed1983

Cold-sensitive nuclear division arrest mutants of the fission yeast Schizosaccharomyces pombe.

Thirteen recessive cold sensitive nuclear division arrest mutants were isolated from the fission yeast Schizosaccharomyces pombe. Twelve unlinked genes were defined; six in chromosome I, three in chromosome II and two in chromosome III. The map positions of three nuclear division arrest genes (nda1, nda2 and nda3) in chromosome II were determined precisely. Together with the previously obtained temperature-sensitive cell division cycle mutations, at least 20 genes appear to control the nuclear division of the fission yeast. Physiological studies indicated that most cold sensitive nda mutants incubated previously at 22 degrees C proceeded with a synchronously normal cell-cycle after temperature shift-up. The morphology of the nuclei and nuclear chromatin region was studied by the 4',6-diamidino-2-phenylindole staining method and by electron microscopy. Each mutant exhibited characteristic nuclear morphology at 22 degrees C, showing the specific blockages. The nda genes seem to control a pathway of structural alterations in the nuclear chromatin region with the order hemisphere, condensed ellipsoid, segregating U-form and separating hemispheres. Two genes, nda2 and nda3, pleiotropically control nuclear division, nuclear location and cell shape. The terminal phenotype of nda2-KM52 is characterized by the nuclear displacement, the absence of a spindle and abnormal locations of spindle pole bodies. The cells of nda3-KM311 were aberrant in shape and contained a partially separated chromatin region with a long spindle. Together with the results of the accompanying paper, we conclude that nda2 and nda3 genes control nuclear and cytoplasmic microtubular organization.

Alleles↗
PubMed1983

Cell division cycle genes nda2 and nda3 of the fission yeast Schizosaccharomyces pombe control microtubular organization and sensitivity to anti-mitotic benzimidazole compounds.

Two genes, nda2 and nda3, previously defined by cold sensitive nuclear division arrest (nda) mutations in the fission yeast Schizosaccharomyces pombe were studied. A mutant nda2-KM52 was found to be supersensitive (at the permissive temperature) to the tubulin-binding drugs such as thiabendazole, methylbenzimidazol-2yl carbamate and nocodazole. A single mutation in nda2 appears to cause both drug supersensitivity and cold sensitivity. The defective phenotypes of nda2-KM52 with a low concentration of the drugs were characterized by nuclear displacement and anomalously situated spindle pole bodies. The allele of the other mutant, nda3-KM311, was sh216 to be linked closely to the ben1 locus, which determines resistance to the drug. The identity of ben1 and nda3 genes was proved by a newly isolated mutant ben1-TB1005; it manifests ben1 resistance and the cold sensitive nda3 phenotype. At 22 degrees C, ben1-TB1005 showed cell branching and deformation characteristic of nda3-KM311. Eleven mutants supersensitive to thiabendazole were newly isolated by replica plating. Four strains were mapped in nda2, while the other four were in nda3. Most of the isolated mutants were blocked at nuclear division in the presence of a low concentration of the drug. Thus, the products of genes nda2 and nda3 (ben1) interact directly or indirectly with the drugs and control, in different ways, microtubular organization in the cells of S. pombe.

Ascomycota↗
PubMed1982

Three-dimensional structure of the crystalloid in the microbody of Kloeckera sp.: composite crystal model.

Electron microscopic investigations using the cryosectioning technique, together with electron diffraction, optical diffraction, and computer simulation, were carried out for the determination of the intrinsic structure of the crystalloid in the microbody of Kloeckera sp. The lattice images seen in the cryosections could be changed from one to another by tilting the specimen at an appropriate angle, the images obtained being well consistent with those obtained by computer simulation. The electron diffraction patterns also agreed with those obtained by optical diffraction. The results demonstrated that the crystalloid was composed of two different types of particles, large and small ones, arranged alternately and making up the composite crystal of rock salt structure. Large particles seemed to consist of alcohol oxidase molecules, while the small particles were presumably made up of catalase molecules.

Bacteria↗
PubMed1982

Combined passive and active immunization for preventing perinatal transmission of hepatitis B virus carrier state.

Prevention of perinatal transmission of hepatitis B virus carrier state in neonates at high risk was attempted by a combined passive and active immunization. Immediately after delivery, ten babies born to mothers who were asymptomatic carriers of hepatitis B surface antigen (HBsAg) and seropositive for hepatitis B e antigen received an intravenous injection of F(ab')2 fragments (200 IU) derived from hepatitis B immune globulin (HBIG). On the following day, none of them revealed detectable levels of the antibody to HBsAg in their sera, and received an intramuscular injection of HBIG (200 IU) which was repeated at 2 and 4 months of age. Vaccination with 40 micrograms of purified, formalin-inactivated HBsAg particles was given to the nine babies at three months and repeated at 4, 5, and 7 months after birth. All of them maintained detectable levels of the antibody and escaped infection throughout the first 12 months of their lives. The one baby who did not have detectable F(ab')2 in serum for 24 hours developed persistent HBs antigenemia which was noticed as early as seven days after birth.

Adult↗