| Project/Area Number |
10670143
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Pathological medical chemistry
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| Research Institution | Jichi Medical School |
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Principal Investigator |
KAWAKAMI Kiyoshi Jichi Medical School, Dept. of Medicine, Professor, 医学部, 教授 (10161283)
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| Project Period (FY) |
1998 – 1999
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| Project Status |
Completed (Fiscal Year 1999)
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| Budget Amount *help |
¥2,700,000 (Direct Cost: ¥2,700,000)
Fiscal Year 1999: ¥1,300,000 (Direct Cost: ¥1,300,000)
Fiscal Year 1998: ¥1,400,000 (Direct Cost: ¥1,400,000)
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| Keywords | myotonic dystrophy / DMAHP / Six5 gene / transcription start site / CTG repeat / target genes / transcription regulatory element / myogenin / Eya genes / Six5 / Sp1 / Sp3 |
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| Research Abstract |
To reveal the involvement of DMAHP/Six5 in pathogenesis of myotonic dystrophy (DM) at the molecular level, we clarified several points described below.
(1)We identified two transcription start sites common to skeletal muscle, heart, and embryo and one site specific to early embryo (El1). All of these sites reside downstream of the CTG repeat. This observation excludes the possibility that the CUG repeat in the transcribed mRNA causes aberrant splicing or translation leading to DM.
(2)We analyzed the transcription regulatory elements of the DMAHP/Six5 gene in P19 cells and identified three Sp1/Sp3 sites as positive regulatory elements and two negative regulatory elements, to one of which an unidentified factor binds.
(3)To identify target genes of DMAHP/Six5 protein, we constructed constitutive active VPl6-Six5 and constitutive repressive Eng-Six5. The constitutive active Six5 functions as expected but the constitutive repressive Six5 did not. The screening of the possible target genes are ongoing using microarray by infecting adenovirus vector containing the VP16-Six5 into cultured cells.
(4)The myogenin promoter has been identified as a target gene for Six1, Six4 protein. We found out that the promoter could be activated by Six5. Co-transfection of Eya genes greatly enhanced the activation. This result suggests a new insight into the DM pathogenesis that diminished expression of Six5 lead to weak cooperative action with Eya leading to reduced expression of myogenin. This might cause the immaturation of skeletal muscle.
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