1989 Fiscal Year Final Research Report Summary
Molecular biological investigation into the enzyme abnormality in muscle phosphofructokinase deficiency
| Project/Area Number |
63440043
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| Research Category |
Grant-in-Aid for General Scientific Research (A)
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| Allocation Type | Single-year Grants |
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| Research Field |
内分泌・代謝学
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| Research Institution | Osaka University Medical School |
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Principal Investigator |
TARUI Seiichiro Osaka University, Dep. Int. Med., Professor, 医学部, 教授 (00028341)
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| Co-Investigator(Kenkyū-buntansha) |
SHIMIZU Takao Osaka University, Dep. Int. Med., Instructor, 医学部, 助手 (40206199)
KUWAJIMA Masamichi Osaka University, Dep. Int. Med., Instructor, 医学部, 助手 (00205262)
NOGUCHI Tamio Osaka University, Dep. Nutr. Physiol. Chem., Assistant Professor, 医学部, 講師 (70135721)
KONO Norio Osaka University, Dep. Int. Med., Assistant Professor, 医学部, 講師 (30093412)
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| Project Period (FY) |
1988 – 1989
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| Keywords | Glycolysis / Key enzyme / Phosphofructokinase / Type VII glycogenosis / Genomic cloning / cDNA cloning / Splicing / Genomic structure |
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| Research Abstract |
Phosphofructokinase (PFK) is a key regulatory enzymes in glycolysis. Deficiency of PFK in muscle (type VH glycogenosis) was first reported by the head investigator of this project and its pathophysiology has been clarified by his laboratory. This project was aimed to clarify the patient's defect at the gene level, and the following results were obtained.
1) The complete length cDNA of normal human muscle PFK was cloned for the first time and the primary structure of this enzyme was determined. 2) Genomic cloning for normal human muscle PFK was performed. Complete structure of this gene, including 22 exons coding for a protein, ranging in length of over 25 kb was determined. Furthermore, alternative RNA splicing and the multiple promoter system in the transcription of this gene were made clear. 3) Muscle MRNA and genomic DNA from a patient with PFK deficiency were analyzed. A 75-base inframe deletion, corresponding to the deletion for 25 amino acid residues, was identified in the full-length muscle PFK cDNA of the patient. Total loss of the enzyme activity in the patient's muscle was explained by this abnormal gene product. This deletion was considered to be generated through the abnormal RNA splicing due to a point mutation at the donor site of an intron, which was identified in the genomic sequence.
In conclusion, the successful results of this project brought these investigators to the final goal in the history of studies on this disease during a quarter of a century, which is nowadays described in the Japanese and foreign medical textbooks as "Tarui disease" after the name of the head investigator. Moreover, PFK deficiency became the first clinical entity among all of glycogenoses, in the sense that the patient's defect was determined at the gene level. Thus, the results of this project will be beneficially accepted by the wide range of investigators of inherited metabolic disorders and will provide an additional suggestion on the RNA splicing mechanism as well.
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