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Your search keyword '"Kazuei Mita"' showing total 4 results
Start Over Author "Kazuei Mita" Journal proceedings of the national academy of sciences of the united states of america
4 results on '"Kazuei Mita"'

1. Transcriptional regulation of juvenile hormone-mediated induction of Krüppel homolog 1, a repressor of insect metamorphosis

Author

Tetsuro Shinoda, Toshiki Namiki, Michiyo Yoshiyama, Yukio Ishikawa, Takumi Kayukawa, Toru Togawa, Chieka Minakuchi, Makoto Kiuchi, Kazuei Mita, Manabu Kamimura, and Shigeo Imanishi

Subjects
DNA, Complementary, Response element, Molecular Sequence Data, Kruppel-Like Transcription Factors, Repressor, Real-Time Polymerase Chain Reaction, Upstream activating sequence, Transcriptional regulation, Basic Helix-Loop-Helix Transcription Factors, Animals, Humans, Cloning, Molecular, Transcription factor, Bombyx, Regulation of gene expression, Multidisciplinary, biology, Base Sequence, Metamorphosis, Biological, Sequence Analysis, DNA, Biological Sciences, biology.organism_classification, Molecular biology, Juvenile Hormones, HEK293 Cells, Gene Expression Regulation, Juvenile hormone
Abstract

The Krüppel homolog 1 gene ( Kr-h1 ) has been proposed to play a key role in the repression of insect metamorphosis. Kr-h1 is assumed to be induced by juvenile hormone (JH) via a JH receptor, methoprene-tolerant (Met), but the mechanism of induction is unclear. To elucidate the molecular mechanism of Kr-h1 induction, we first cloned cDNAs encoding Kr-h1 ( BmKr-h1 ) and Met ( BmMet1 and BmMet2 ) homologs from Bombyx mori . In a B. mori cell line, BmKr-h1 was rapidly induced by subnanomolar levels of natural JHs. Reporter assays identified a JH response element ( k JHRE), comprising 141 nucleotides, located ∼2 kb upstream from the BmKr-h1 transcription start site. The core region of k JHRE (GGCCTCCACGTG) contains a canonical E-box sequence to which Met, a basic helix–loop–helix Per-ARNT-Sim (bHLH–PAS) transcription factor, is likely to bind. In mammalian HEK293 cells, which lack an intrinsic JH receptor, ectopic expression of BmMet2 fused with Gal4DBD induced JH-dependent activity of an upstream activation sequence reporter. Meanwhile, the k JHRE reporter was activated JH-dependently in HEK293 cells only when cotransfected with BmMet2 and BmSRC, another bHLH–PAS family member, suggesting that BmMet2 and BmSRC jointly interact with k JHRE. We also found that the interaction between BmMet2 and BmSRC is dependent on JH. Therefore, we propose the following hypothesis for the mechanism of JH-mediated induction of BmKr-h1 : BmMet2 accepts JH as a ligand, JH-liganded BmMet2 interacts with BmSRC, and the JH/BmMet2/BmSRC complex activates BmKr-h1 by interacting with k JHRE.

Published
2012

2. Nonsense mutation at Tyr-4046 in the DNA-dependent protein kinase catalytic subunit of severe combined immune deficiency mice

Author

Masahiko Mori, Toshiyuki Saito, Akira Fujimori, Masahiro Itoh, Kazuei Mita, Kouichi Tatsumi, Ryoko Araki, Kiyohiro Hamatani, Ryutaro Fukumura, Mitsuoki Morimyo, Masahiro Muto, and Masumi Abe

Subjects
Macromolecular Substances, Nonsense mutation, Molecular Sequence Data, Gene Expression, Mice, Inbred Strains, DNA-Activated Protein Kinase, Mice, SCID, Biology, Protein Serine-Threonine Kinases, Polymerase Chain Reaction, DNA-Dependent Protein Kinase Catalytic Subunit, Mice, Open Reading Frames, Phosphatidylinositol 3-Kinases, Gene expression, Animals, Humans, Point Mutation, Amino Acid Sequence, Transversion, Codon, Gene, DNA Primers, Gene Library, Genetics, Multidisciplinary, Base Sequence, Sequence Homology, Amino Acid, Point mutation, Nuclear Proteins, Biological Sciences, Molecular biology, Stop codon, DNA-Binding Proteins, Open reading frame, enzymes and coenzymes (carbohydrates), Phosphotransferases (Alcohol Group Acceptor), Tyrosine, biological phenomena, cell phenomena, and immunity
Abstract

The severe combined immune deficiency (SCID) mouse was reported as an animal model for human immune deficiency. Through the course of several studies, the DNA-dependent protein kinase catalytic subunit (DNA-PKcs) gene came to be considered a candidate for the SCID-responsible gene. We isolated an ORF of the murine DNA-PKcs gene from SCID mice and their parent strain C.B-17 mice and determined the DNA sequences. The ORF of the murine DNA-PKcs gene contained 4128-aa residues and had 78.9% homology with the human DNA-PKcs gene. A particularly important finding is that a T to A transversion results in the substitution of termination codon in SCID mice for the Tyr-4046 in C.B-17 mice. No other mutation was detected in the ORF of the gene. The generality of this transversion was confirmed using four individual SCID and wild-type mice. The substitution took place in the phosphatidylinositol 3-kinase domain, and the mutated gene encodes the truncated products missing 83 residues of wild-type DNA-PKcs products. Furthermore, the quantity of DNA-PKcs transcript in wild-type and SCID cells was almost equal. These observations indicate that the DNA-PKcs gene is the SCID-responsible gene itself and that the detected mutation leads to the SCID aberration.

Published
1997

3. Repression of tyrosine hydroxylase is responsible for the sex-linked chocolate mutation of the silkworm, Bombyx mon.

Author

Chun Liu, Kimiko Yamamoto, Ting-Cai Cheng, Keiko Kadono-Okuda, Junko Narukawa, Shi-Ping Liu, Vu Han, Ryo Futahashi, Kurako Kidokoro, Hiroaki Noda, Isao Kobayashi, Toshiki Tamura, Akio Ohnuma, Yutaka Banno, Fang-Ying Daia, Zhong-Huai Xiang, Marian R. Goldsmith, Kazuei Mita, and Qing-You Xia

Subjects
SILKWORMS, TYROSINE, GENETIC mutation, GENETIC carriers, TRANSPOSONS
Abstract

Pigmentation patterning has long interested biologists, integrating topics in ecology, development, genetics, and physiology. Wild-type neonatal larvae of the silkworm, Bombyx mori, are completely black. By contrast, the epidermis and head of larvae of the homozygous recessive sex-linked chocolate (sch) mutant are reddish brown. When incubated at 30 °C, mutants with the sch allele fail to hatch; moreover, homozygous mutants carrying the allele sch lethal (schl) do not hatch even at room temperature (25 °C). By positional cloning, we narrowed a region containing sch to 239,622 bp on chromosome 1 using 4,501 backcross (BC1) individuals. Based on expression analyses, the best sch candidate gene was shown to be tyrosine hydroxylase (BmTh). BmTh coding sequences were identical among sch, schl, and wild-type. However, in sch the ∼70-kb sequence was replaced with ∼4.6 kb of a Tc1-mariner type transposon located ∼6 kb upstream of BmTh, and in schl, a large fragment of an L1Bm retrotransposon was inserted just in front of the transcription start site of BmTh. In both cases, we observed a drastic reduction of BmTh expression. Use of RNAi with BmTh prevented pigmentation and hatching, and feeding of a tyrosine hydroxylase inhibitor also suppressed larval pigmentation in the wild-type strain, pnd+ and in a pS (black-striped) heterozygote. Feeding L-dopa to sch neonate larvae rescued the mutant phenotype from chocolate to black. Our results indicate the BmTh gene is responsible for the sch mutation, which plays an important role in melanin synthesis producing neonatal larval color. [ABSTRACT FROM AUTHOR]

Published
2010
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4. The construction of an EST database for Bombyx mori and its application.

Author

Kazuei Mita, Mitsuoki Morimyo, Annibale A., Kazuhiro Okano, Yoshiko Koike, Annibale A., Junko Nohata, Annibale A., Hideki Kawasaki, Annibale A., Keiko Kadono-Okuda, Annibale A., Kimiko Yamamoto, Annibale A., Masataka G. Suzuki, Toru Shimada, Goldsmith, Marian R., and Maeda, Susumu

Subjects
*SILKWORMS, *GENOMES, *GENE libraries, *CLONING, *GENETIC engineering
Abstract

To build a foundation for the complete genome analysis of Bombyx mori, we have constructed an EST database. Because gene expression patterns deeply depend on tissues as well as developmental stages, we analyzed many cDNA libraries prepared from various tissues and different developmental stages to cover the entire set of Bombyx genes. So far, the Bombyx EST database contains 35,000 ESTs from 36 cDNA libraries, which are grouped into &Sime;11,000 nonredundant E5Ts with the average length of 1.25 kb. The comparison with FlyBase suggests that the present EST database, Silk Base, covers >55% of all genes of Bombyx. The fraction of library-specific ESTs in each cDNA library indicates that we have not yet reached saturation, showing the validity of our strategy for constructing an EST database to cover all genes. To tackle the coming saturation problem, we have checked two methods, subtraction and normalization, to increase coverage and decrease the number of housekeeping genes, resulting in a 5-11% increase of library-specific ESTs. The identification of a number of genes and comprehensive cloning of gene families have already emerged from the SilkBase search. Direct links of SilkBase with FlyBase and WormBase provide ready identification of candidate Lepidopteraspecific genes. [ABSTRACT FROM AUTHOR]

Published
2003
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