| Project/Area Number |
60560117
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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 |
発酵・醸造
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| Research Institution | HIROSHIMA UNIVERSITY |
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Principal Investigator |
MIYAKAWA TOKICHI FACULTY OF ENGINEERING, HIROSHIMA UNIVERSITY, 工学部, 助教授 (10116676)
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| Project Period (FY) |
1985 – 1986
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| Project Status |
Completed (Fiscal Year 1986)
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| Budget Amount *help |
¥1,800,000 (Direct Cost: ¥1,800,000)
Fiscal Year 1986: ¥400,000 (Direct Cost: ¥400,000)
Fiscal Year 1985: ¥1,400,000 (Direct Cost: ¥1,400,000)
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| Keywords | Basidiomycetous yeast / Sexual conjugation / Cell surface proteins / Mating pheromone / 細胞間認識 |
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| Research Abstract |
Haploid vegetative cells (mating type aband AB) of Tremella mesenterica, a hetero-basidiomycetous yeast, differentiate to gamete cells reponding to a lipopeptidyl mating pheromone secreted by the cells of the opposite mating type. Several species of mating-type specific cell surface proteins as revealed by lactoperoxidase-catalayzed iodination and SDS-PAGE appear during the sexual differentiation. These surface proteins were rapidly hydrolyzed by a pheromone-activated cell surface acid protease. A glycoprotein with MW 50,000 (50K) was a major labeled species released into the culture medium from each mating type cells labeled with <^(125)I> . The two glycoproteins had different isoelectric points. Both mating-type specific and nonspecific peptides were detected by peptide mapping after proteolysis with V8 protease, indicating that the 50K protein consits of mating type specifc and nonspecific domains. It may be possible that the two 50Ks have a common polypeptide with mating type specific modifications such as phosphorylation. The 50Ks stimulated sexual agglutination of the gamete cells. The 50Ks bound to the gamete cells of both mating type with no apparent binding specificities. From these results it was indicated that the 50Ks are cell recognition glycoproteins at the surface of the gamete cells, and molecules (50K) with multiple binding sites (for both mating type cells) are released into the medium and stimulate the formation of sexual agglutitation complexes in a liquid medium as a diffusible molecule.
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