1991 Fiscal Year Final Research Report Summary
Cloning of total cDNA for desmoplakin and its molecular analysis and chromosomal mapping
| Project/Area Number |
02454280
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
Dermatology
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| Research Institution | Keio University |
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Principal Investigator |
HASHIMOTO Takashi Keio Univ. School of Medicine, Assis. Prof., 医学部, 講師 (20129597)
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| Co-Investigator(Kenkyū-buntansha) |
KUDOH Jun Keio Univ. School of Medicine, Instructor, 医学部, 助手 (80178003)
SHIMIZU Nobuyoshi Keio Univ. School of Medicine, Professor, 医学部, 教授 (50162706)
TANAKA Masaru Keio Univ. School of Medicine, Instructor, 医学部, 助手 (40188339)
NISHIKAWA Takeji Keio Univ. School of Medicine, Professor, 医学部, 教授 (50051579)
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| Project Period (FY) |
1990 – 1991
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| Keywords | Epidermis / Cell adhesion / Desmosome / Desmoyokin / Molecular biology / Biochemistry |
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| Research Abstract |
We have isolated a monocloanl antibody that was first thought to react with desmoplakins I and II, a major desmosomal plaque protein. However, after the monoclonal antibody was characterized further in detail, the monoclonal antibody was found to react with desmoyokin, a newly identified 680 kD plaque protein of the desmosomes. By immunoscreening our mouse keratinocyte library with the monoclonal antibody, we have isolated several positive cDNA clones, one of which was further characterized. The cDNA insert(DY6, 3693 bp)hybridized with an extremely large mRNA from either human or mouse keratinocytes. The recombinant protein produced by DY6 was reacted not only with the monoclonal antibody used for immunoscreening but also with anti-desmoyokin monoclonal antibody. Nucleotide and deduced amino acid sequences of DY6 showed no significant homology with previously reported sequences including other desmosomal components. Analysis of the amino acid sequence revealed that DY6 consists of about ten highly homologous repeats about 128 residues long, each comprising four distinct segments. Furthermore, the 128 residue repeats exhibit a quasi seven-residue substructure that is, however, fundamentally different from the heptad repeat seen in the rod domains of alpha-fibrous proteins. Secondary structure prediction shows that the conformation adopted is not alpha-helical, but most probably an antiparallel beta-sheet structure with one face apolar and the other comprising a periodic distribution of acidic and basic residues. These and other results suggest that desmoyokin has a unique structure and function among desmosomal components, and that DY6 may encode a major part of the C-terminal globular domain of desmoyokin.
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Research Products
(4 results)
