1990 Fiscal Year Final Research Report Summary
Molecular Evolutional Study on Gene-expression of Enzymes Responsible for Uric Acid-degradation
| Project/Area Number |
01580202
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
代謝生物化学
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| Research Institution | Fujita-Health University |
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Principal Investigator |
ITO Masaki Fujita-Health University, 医学部, 講師 (50116779)
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| Co-Investigator(Kenkyū-buntansha) |
OGAWA Hisamitsu Fujita-Health University, 医学部, 助教授 (80101658)
TAKAGI Yasuyuki Fujita-Health University, 医学部, 教授 (50037313)
OGAWA Hisamitsu Fujita-Health University (80101658)
OGAWA Hisamitsu Fujita-Health University (80101658)
OGAWA Hisamitsu Fujita-Health University (80101658)
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| Project Period (FY) |
1989 – 1990
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| Keywords | Uricase / Uric acid / Gene structure / Molecular evolution |
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| Research Abstract |
We paid attention to differential expressions of uricases in various living cells in order to carry out the research project. It has been supposed that uricase is expressed at the early stage of chicken embryo but that it is not at the later stage and in the adult chicken. In order to show the presence of uricase at the chicken embryo, we tried to detect a cross-reactive product against anti-rat liver uricase and a cDNA homologous to rat liver uricase cDNA in the early stage of chicken embryo. We observed the product and the cDNA. However, a little amount of uricase was expressed in chicken embryo and it was difficult to determine the amino acid sequence for proving the product and the cDNA. Then, we turned the attention to rat liver uricase which is expressed in the adult stage and intended to study the molecular evolution of uricase genes. We used rat liver uricase cDNA as a probe to isolate rat uricase gene. Five clones containing the uricase gene were isolated from rat genomic libraries. The gene spans 40 kb and consists of 8 exons. All the exon-intron junctional sequences conform to GT/AG rule. It was found that the enzyme is encoded by a single copy-gene from the coincidence between the restriction map and Southern blot analysis. The transcriptional initiation site in rat uricase gene was determined by primer-extension analyses and Sl protection analysis. The analyses indicated the differential use to consecutive nucleotides. The principal one is located 55 nucleotides upstream from the first methionine codon. Nucleotide sequence analysis of the 5'-flanking region showed the presences of a TATA sequence, a CAAT sequence and a palindromic sequence surrounded by a direct repeat. The typical promoter sequence could be involved in the liver-specific expression of uricase.
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