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R Morimoto

Publications and source records attributed to R Morimoto.

36 records · Page 2Linked to original sources
PubMed1984

[Concentration of piperacillin in bone].

Eighteen patients received 2.0 grams of piperacillin sodium (PIPC) intravenously. The concentrations of PIPC in serum, cancellous bone, and cortical bone were measured approximately 30 minutes after injection. Serum concentrations ranged from 9.10 to 167.0 micrograms/ml (mean 95.61 +/- 10.03 micrograms/ml). Cortical bone concentrations varied between 0 and 17.5 micrograms/g (mean 4.58 +/- 1.03 micrograms/g). The levels measured in cancellous bone ranged from 0.62-13.1 micrograms/g (mean 8.07 +/- 1.43 micrograms/g). PIPC achieved high concentrations in bone.

Aged↗
PubMed1981

Mitochondrial transcription complex from Saccharomyces cerevisiae.

A DNA protein complex has been isolated from the mitochondria of Saccharomyces cerevisiae. The complex transcribes RNA complementary to mtDNA in a nonrandom manner. The RNA polymerase activity contained in the transcription complex is not dependent on the addition of exogenous template. The activity is rendered template-dependent by autolysis and can be further purified by heparin-Sepharose 4B chromatography. The activity is inhibited by heparin, Mn2+, and increasing ionic strength. The activity requires Mg2+ and ribonucleotides. The preferred template for the template dependent activity is poly[d(AT)]. The majority of the RNA synthesized by the transcription complex from endogenous DNA is complementary to the DNA strands directing the synthesis of the large and small ribosomal RNA. In yeast the 21 S and 14S rRNA genes are widely separated, therefore the transcription of these two regions but not of the intervening regions by the transcription complex suggests the existence of at least two transcriptional promoters on the yeast mitochondrial genome.

DNA, Fungal↗
PubMed1981

Fine structural analysis of the chicken pro alpha 2 collagen gene.

Forty-two kilobase pairs of cloned chicken DNA containing 80% of the pro alpha 2 (type I) collagen gene and 8 kilobase pairs of 3' flanking sequences have been isolated. Detailed analysis of these clones indicates that this collagen gene spans approximately 40 kilobase pairs of DNA and contains on the order of 50 introns. The fine structure of 40% of the pro alpha 2 gene, including its 3' end, was determined by Southern blot restriction endonuclease mapping using a 2.6-kilobase pair procollagen cDNA clone pCg45, as a probe, and by DNA sequence determination of more than 2 kilobase pairs of this part of the genome. Exons in the triple-helical coding region are all multiples of the 9 base pairs coding for the Gly-X-Y triplet and vary in size from 45 to 108 base paris. The sequences of all six exons in a 3.8-kilobase pair EcoRI fragment were determined. One of these, a 249-base pair exon, joins the collagen domains; it codes for the last 15 amino acids of the triple-helical coding region, the telopeptide, and the first 53 amino acids of the carboxy-terminal propeptide.

Animals↗
PubMed1981

Sequence homologies in the 5' regions of four Drosophila heat-shock genes.

We report nucleotide sequences of the regions surrounding the 5' ends of the genes for Drosophila melanogaster heat-shock proteins hsp83, hsp68, and hsp26, located at chromosome positions 63BC, 95D, and 67B, respectively. As in other eukaryotic genes, the sequence T-A-T-A-A-A-A-T occurs about 30 nucleotides upstream from the sites of mRNA initiation. Three additional sequence homologies and a dyad symmetry were noted at approximately corresponding locations in the three genes and in the gene for another heat-shock protein, hsp70. We also found an intron near the 5' end of the hsp83 gene, with sequences at its boundaries typical of splice sites found in other organisms.

Animals↗
PubMed1980

Four heat shock proteins of Drosophila melanogaster coded within a 12-kilobase region in chromosome subdivision 67B.

Unique coding sequences for four heat shock proteins of Drosophila melanogaster, hsp 28, hsp 26, hsp 23, and hsp 22, are clustered in a 12-kilobase interval at chromosome subdivision 67B. The four genes are not transcribed in the same direction and each gives rise to a separate messenger RNA, with no indication of intervening sequences. Including the present results, the genes for all seven major heat shock proteins of D. melanogaster are now cloned are found to exhibit a variety of patterns of organization at the five loci they occupy.

Animals↗
PubMed1979

Transcription, processing, and mapping of mitochondrial RNA from grande and petite yeast.

Mitochondrial RNA (mtRNA) from petite yeast strains was analyzed by electrophoresis in agarose-urea, acrylamide-urea, and agarose-methyl mercuric hydroxide gels, and by transfer to diazobenzyloxy-methyl paper and hybridization to labeled mitochondrial DNA (mtDNA). Petites contain numerous mitochondrial transcripts, including processed species like 21 S and 14 S rRNA. Petite transcripts were found to fall into three classes: 1) bands that comigrate with grande mtRNA species; 2) "group-specific" new bands found in multiple strains and coinciding with specific regions of the mitochondrial genome; and 3) "strain-specific" new bands found only in individual petite strains. A deletion map was constructed in which we used the presence or absence of the first two types of mtRNA bands in specific strains, and the restriction endonuclease map of these strains. This map confirmed the localization of 21 S and 14 S rRNA, which were mapped previously by hybridization, and also localized more than 20 additional mtRNA species. The mtRNA species were grouped in regions of the genome in a fashion that strongly suggests that many of them are precursors to fully processed mtRNA species. Hybridization experiments with grande mtRNA and cloned mtDNA fragments have shown the same kind of transcript grouping. Other hybridization experiments have demonstrated two apparent precursors to 21 S rRNA (3700 nucleotides) measuring 5500 and 4500 nucleotides. Processed tRNAs are found only in petites that contain a specific region of the genome near the P (paromomycin resistance) locus. When this region is absent, processed tRNAs are not detected, even for tRNA genes quite distant from the P locus. Since this phenotype is expressed in petites that lack mitochondrial protein synthesis, and since it maps to a specific location in the mitochondrial genome, there appears to be a mtRNA species which has a role in processing of mitochondrial tRNA.

DNA, Mitochondrial↗
PubMed1979

Physical mapping of the Xba I, Hinc II, Bgl II, Xho I, Sst I, and Pvu II restriction endonuclease cleavage fragments of mitochondrial DNA of S. cerevisiae.

A detailed molecular dissection of the yeast mitochondrial genome can be made with restriction endonucleases that generate site-specific cuts in DNA. The ordering of restriction fragments provides the basis of the physical mapping of mitochondrial transcripts and antibiotic resistance (antR) loci, and is a means of analyzing the molecular organization of mtDNA of petite and mit- deletion mutants. We have previously mapped the sites in the mtDNA of yeast strain MH41-7B recognized by the endonucleases Eco RI, Hpa I, Hind III, Bam HI, Sal I, Pst I, and Hha I, providing a total of 41 cleavage sites. We have now mapped the sites recognized by the endonucleases Xba I, Hinc II, Bgl II, Pvu II, Xho I, and Sst I, which make 6, 13, 5, 6, 2, and 2 cuts, respectively. Fragment maps for each of these endonuclease sites were derived by analysis of the products of double-enzyme digests and by hybridization of 3H-cRNA probes transcribed from low-kinetic-complexity petite mtDNAs to restriction fragments generated by various combinations of enzymes.

Base Sequence↗
PubMed1979

Physical mapping of the yeast mitochondrial genome: derivation of the fine structure and gene map of strain D273-10B and comparison with a strain (MH41-7B) differing in genome size.

(1) We have derived a fine-structure map of the 70 kb mitochondrial genome of the yeast S. cerevisiae, strain D273-10B, and compared it with our previous maps for strain MH41-7B. Restriction fragment maps for 56 enzyme recognition sites for 13 endonucleases, Eco RI, Hpa I, Bam HI, Hha I, Hinc II, Xba I, Hind III, Bgl II, Pvu II, Sal I, Pst I, Sst I, and Xho I, have been derived. We have used several methods to obtain these maps: (a) Four enzymes (Sal I, Sst I, Xho I, Pst I), each of which cuts D273-10B mtDNA at a single site, were employed to localize and orient fragments from multi-site enzyme digests that are cleaved by the single-site enzyme. (b) Radioactively labeled probes (rRNA or copy RNA [cRNA] transcribed from simple-sequence petite mtDNA) were hybridized to restriction fragments from different digests for identification of fragments which share common sequences. (c) The products of double or triple enzyme digests were identified for mapping and confirmation of the localization of restriction sites. (2) The antibiotic-resistant (antR) loci for erythromycin (E), chloramphenicol (C), paromomycin (P), and oligomycin (OI, OII) were positioned on the physical restriction map by hybridization of 3H-labeled cRNA transcribed from simple-sequence petite mtDNAs that retain a single genetic antR marker to appropriate restriction fragments bound to nitrocellulose filters. (3) Mitochondrial transcripts (21s rRNA, 14s rRNA, and tRNAs) labeled with 125I were hybridized to restriction fragments for identification of the corresponding coding sequence. (4) The gene order and localization of the antR loci and mitochondrial transcripts are as follows: C(0-1.5u)-tRNA I(0-21.5u)-P(29-36.6u)-tRNA II(29-46.4u)-14s rRNA(36-38.3u)-OII(60.3-62.5u) - tRNA III(73-76u) - OI(78.6-83.0u) - tRNA IV(82.5-83.0u) - E(94.2-98.6u) - 21s rRNA (94.2-99.4u). (5) The DNA fine structure and gene map of the 70 kb D273-10B mtDNA were compared to the map of the larger MH41-7B (76 kb) mtDNA. There are 56 restriction sites on D273-10B and 67 sites on MH41-7B for the 13 enzymes studied. The additional restriction sites are largely accounted for by the presence, in MH41-7B, of two sets of sequences, "A" (2.7 kb) and "B" (3.0 kb), located on either side of the OII marker. The remainder of the fragments map is remarkably similar for the two strains. The distances separating the antR loci and the mitochondrial transcripts are very similar except in the two regions surrounding OII.

DNA Restriction Enzymes↗
PubMed1979

Studies of cloned sequences from four Drosophila heat shock loci.

DNA cloned from the D. melanogaster (Oregon R) heat shock loci at 63BC and 95D codes for the 83,000 and the 68,000 dalton heat shock proteins, respectively. Both coding sequences occur once per haploid genome. Sequences complementary to messenger RNA for the 70,000 dalton heat shock protein are represented five times, twice at 87A and three times at 87 C. The copies at 87A differ characteristically from those at 87C in an interval of a few hundred bp near the 5' end of the messenger sequence, and the corresponding two classes of hsp 70 messenger RNA are found on polysomes after heat shock. Within this differential region, there is about 15% divergence between messenger sequences cloned from the two loci, while in the rest of the messenger region examined the homology is much closer although still imperfect. Unexpectedly, considerable homology is found between the sequence for the 68,000 dalton heat shock protein at 95D and the sequences for the 70,000 dalton protein at 87A and 87C, and between these sequences and a site in 87D. Messenger RNA molecules of 2.4, 2.55 and 3.05 kb code for the 68,000, 70,000 and 83,000 dalton heat shock proteins and hybridize to apparently uninterrupted DNA sequences of 2.1, 2.25 and 2.6 kb, respectively.

Animals↗
PubMed1978

Physical mapping of genes on yeast mitochondrial DNA: localization of antibiotic resistance loci, and rRNA and tRNA genes.

We have physically mapped the loci conferring resistance to antibiotics that inhibit mitochondrial protein synthesis (erythromycin, chloramphenicol and paromomycin) or respiration (oligomycin I and II), as well as the 21s and 14s rRNA and tRNA genes on the restriction map of the mitochondrial genome of the yeast Saccharomyces cerevisiae. The mitochondrial genes were localized by hybridization of labeled RNA probes to restriction fragments of grande (strain MH41-7B) mitochondrial DNA (mtDNA) generated by endonucleases EcoRI, HpaI, BamHI, HindIII, SalI, PstI and HhaI. We have derived the HhaI restriction fragment map of MH41-7B mit DNA, to be added to our previously reported maps for the six other endonucleases. The antibiotic resistance loci (antR) were mapped by hybridization of 3H-cRNA transcribed from single marker petite mtDNA's of low kinetic complexity to grande restriction fragments. We have chosen the single Sal I site as the origin of the circular physical map and have positioned the antibiotic loci as follows: C (99.5-1.Ou)--P (27-36.Ou)--OII (58.3-62u--OI (80-84u)--E (94.4-98.4u). The 21s rRNA is localized at 94.4-99.2u, and the 14s rRNA is positioned between 36.2-39.8u. The two rRNA species are separated by 36% of the genome. Total mitochondrial tRNA labeled with 125I hybridized primarily to two regions of the genome, at 99.5-11.5u and 34-44u. A third region of hybridization was occasionally detected at 70--76u, which probably corresponds to seryl and glutamyl tRNA genes, previously located to this region by petite deletion mapping.

Chloramphenicol↗
PubMed1978

Restriction enzyme analysis of mitochondrial DNAs of petite mutants of yeast: classification of petites, and deletion mapping of mitochondrial genes.

We have analyzed the restriction digest patterns of the mitochondrial DNA from 41 cytoplasmic petite strains of Saccharomyces cerevisiae, that have been extensively characterized with respect to genetic markers. Each mitochondrial DNA was digested with seven restriction endonucleases (EcoRI, HPaI, HindIII, BamHI, HhaI, SalI, and PstI) which together make 41 cuts in grande mitochondrial DNA and for which we have derived fragment maps. The petite mitochondrial DNAs were also analyzed with HpaII, HaeIII, and AluI, each of which makes more than 80 cleavages in grande mitochondrial DNA. On the basis of the restriction patterns observed (i.e., only one fragment migrating differently from grande for a single deletion, and more than one for multiple deletions) and by comparing petite and grande mitochondrial DNA restriction maps, the petite clones could be classified into two main groups: (1) petites representing a single deletion of grande mitochondrial DNA and (2) petites containing multiple deletions of the grande mitochondrial DNA resulting in rearranged sequences. Single deletion petites may retain a large portion of the grande mitochondrial genome or may be of low kinetic cimplexity. Many petites which are scored as single continuous deletions by genetic criteria were later demonstrated to be internally deleted by restriction endonuclease analysis. Heterogeneous sequences, manifested by the presence of sub-stoichiometric amounts of some restriction fragments, may accompany the single or multiple deletions. Single deletions with heterogeneous sequences remain useful for mapping if the low concentration sequences represent a subset of the stoichiometric bands. Using a group of petites which retain single continuous regions of the grande mitochondrial DNA, we have physically mapped antibiotic resistance and mit- markers to regions of the grande restriction map as follows: C (99.3--1.4 map units)--OXI-1 (2.5--15.7)--OXI-2 (18.5--25)--P (28.1--34.2)--OXI-3 (32.2--61.2--OII (60--62)--COB (64.6--80.8--0I (80.4--85.7)--E (95--98.9).

DNA Restriction Enzymes↗
PubMed1977

Restriction cleavage map of mitochonrial DNA from the yeast Saccharomyces cerevisiae.

Mitochondrial DNA (mtDNA) from the yeast Saccharomyces cerevisiae was cleaved by restriction endonucleases Eco RI, Hpa I, Bam HI, Hind III, Pst I, and Sal I, yielding 10, 7, 5, 6, 1, and 1 fragments, respectively. A physical ordering of the restriction sites on yeast mtDNA has been derived. Yeast mtDNA cannot be isolated as intact molecules, and it contains nicks and gaps which complicate the use of conventional fragment mapping procedures. Nevertheless, the position of each of the restriction sites was obtained primarily by reciprocal redigestion of isolated restriction fragments. This procedure was supplemented by co-digestion of mtDNA with a multisite enzyme and a single-site enzyme (i.e., Sal I or Pst I) which provided a unique orientation for overlapping fragments cleaved by Sal I or Pst I. The data obtained from these approaches were confirmed by analysis of double and triple enzyme digests. Analysis of partial digest fragments was used for positioning of the smallest Eco RI fragment. A comparison of mtDNA from four grande strains (MH41-7B, 19d, TR3-15A, and MH32-12D) revealed similar, but slightly varying restriction patterns, with an identical genome size for each of approximately 5 X 10(-7) d or 75 kb. A fifth grande strain, D273-10B from S. cerevisiae, revealed restriction patterns different from those of the above strains, with a smaller genome size of 70 kb.

DNA Restriction Enzymes↗
PubMed1975

Restriction endonuclease analysis of mitochondrial DNA from grande and genetically characterized cytoplasmic petite clones of Saccharomyces cerevisiae.

Digestion of grande mitochondrial DNA (mtDNA) BY EcoRI restriction endonuclease gives rise to nine fragments with a total molecular weight of 51.8 x 10(6). HindIII digestion yields six fragments with a similar total molecular weight. Specific restriction fragments can be detected despite the fact that yeast mtDNA consists of a heterogeneous distribution of randomly broken molecules. Digestion patterns of 10 genetically characterized petite clones containing various combinations of five antiobiotic resistance markers indicate that the petite mtDNA predominantly represents deletion of the grande genome. The petite mtDNAs contained up to seven EcoRI restriction fragments which comigrate with grande restriction fragments, and at least one fragment that did not correspond to any in the grande. Some strains contained multiple fragments with mobility different from that of grande; these fragments were usually present in less than molar concentrations. The genetic markers were associated with individual sets of restriction fragments. However, several internal inconsistencies prevent the construction of a definitive genetic fragment map. These anomalies, together with the digestion patterns, provide strong evidence that, in addition to single contiguous deletion, other changes such as multiple deletion and heterogeneity of mtDNA populations are present in some of the petite mtDNAs.

DNA Restriction Enzymes↗