| Project/Area Number |
06670360
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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 |
Immunology
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| Research Institution | Fukushima Medical College |
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Principal Investigator |
ENDO Yuichi Fukushima Medical College, Department of Biochemistry, Associate Professor, 医学部, 助教授 (20117427)
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| Project Period (FY) |
1994 – 1995
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| Project Status |
Completed (Fiscal Year 1995)
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| Budget Amount *help |
¥2,200,000 (Direct Cost: ¥2,200,000)
Fiscal Year 1995: ¥900,000 (Direct Cost: ¥900,000)
Fiscal Year 1994: ¥1,300,000 (Direct Cost: ¥1,300,000)
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| Keywords | Animal lectin / Collagen-like domain / Fibrinogen-like domain / cDNA / Host defense / opsonin / gene structure / コラーゲン様構造 / フィブリノーゲン様構造 |
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| Research Abstract |
Collectins are C-type lectins with collagenous and carbohydrate recognition domains and are involved in the first line host defense against pathogens. We report here a novel Ca^<2+>-dependent and ClcNAc-binding lectin consisting of subunit of 35 kDa (P35) with a collagenlike sequence. It forms a homopolymer by means of intermolecular disulfide bondingas is the case with collectins, P35 cDNA was cloned from a human liver cDNA library, and the deduced amino acid sequence of 313 residues revealed that the mature form of p35 consists mainly of collagen-and fibrinogen-like domains. The latter contained two protential Ca^<2+>-binding sites that may be involved in carbohydrate binding. The overall sequence of P35 was highly homologous to porcine ficolins alpha and beta. P35 enhanced phagocytosis of Salmonella typhimurium by neutrophils, suggesting an opsonic effect via the collagen region. Therefore, P35 represents a new type of GlcNAc-binding lectin with structural and functional similarities to collectins involved in innate immunity.
We isolated genomic clones of the P35 gene and found that P35 is encoded by eight exons. In addition, we isolated another distinct genomic clone corresponding to the upstream region of a P35-related gene which has an exon organization closely resembling that of the P35 gene. Northern blotting revealed that the P35 gene is expressed mainly in liver, whereas the P35-related gene is expressed in lung and peripheral blood leukocytes, demonstrating tissue-specific expression of these two genes. Both genes were assigned to a closely related region of chromosome 9 at 9934. Further studies are needed to elucidate the function of the P35-related gene product, and to establish the structural and functional relationship with P35.
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