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Elucidation of Mechanisms in Fimbrial Morphogenesis in Periodontopathogens

牙周病菌菌毛形态发生机制的阐明

基本信息

批准号：
15591957
负责人：
YOSHIMURA Fuminobu
金额：
$ 2.3万
依托单位：
Aichi-Gakuin University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2003
资助国家：
日本
起止时间：
2003 至 2005
项目状态：
已结题

项目摘要

1.Fimbriae in Porphyromonas gingivalis, a periodontopathogenP.gingivalis seems to carry three different types of fimbriae which are composed of 40-kDa FimA,75-kDa Mfa, and 53-kDa protein, respectively, as a major subunit.2.Distribution of the three fimbriae in P.gingivalisStrain W83 seems to carry none of them. Although it has the fimA (genotype IV) gene, it does not seem to express FimA fimbriae. Because the mfa gene is disrupted in the chromosome, it does not produce Mfa fimbriae. Two fimbriae, FimA and Mfa, are produced in strain ATCC 33277. Some of the P.gingivalis strains including 381 appear to have the three fimbriae.3.Variation of fimA fimbriaeThere are six genotypes in the fimA gene, thus far reported. We have purified fimbriae from genotype I,Ib, and II strains. They have a plenty of fimbriae for purification. However, we do not know whether all the genotype strains carry a plenty of fimbraie on the cell surface.4.Different extraction methods for fimbriae from strains with different fimA genotypesGenotype I fimbraie can be selectively extracted by a simple washing of bacterial cells with a mild buffer. However, other genotype fimbraie of Ib and II could not be extracted by such washing. They can be solubilized through the cell breakage by a French Press. These results might imply that they have fibers with very different lengths. This assumption that genotype I fimbriae are long, but other genotypes of fimbraie are too short to be sheared off from the cell surfaces could be verified.5.Regulation in fimbrial morphogenesisThe genes of fimXY appear to play an important role in expression of fimA protein in fimbrial morphogenesis. The product of the fimR gene, a positive regulator, is discovered to bind to the region upstream from fimXY for production of the fimbrial protein.

1.牙龈卟啉单胞菌（Porphyromonas gingivalis）的菌毛主要由40-kDa的FimA、75-kDa的Mfa和53-kDa的Mfa蛋白组成。虽然它有fimA（基因型IV）基因，但似乎不表达FimA菌毛。由于mfa基因在染色体中被破坏，它不产生Mfa菌毛。在菌株ATCC 33277中产生两种菌毛，FimA和Mfa。381株牙龈卟啉单胞菌中的部分菌株似乎具有这三种菌毛。3. fimA菌毛的变异目前已报道的fimA基因有6种基因型。我们已经从基因型I、Ib和II菌株中纯化了菌毛。它们有大量的菌毛用于净化。4.不同fimA基因型菌株菌毛的不同提取方法用温和的缓冲液洗涤细菌细胞，可以选择性地提取基因I型菌毛。然而，通过这种洗涤不能提取Ib和II的其他基因型菌毛。它们可以通过French Press的细胞破碎来溶解。这些结果可能意味着它们具有非常不同长度的纤维。基因型I菌毛较长，而其他基因型菌毛较短，不能从细胞表面剪下，这一假设可以得到证实。5.菌毛形态发生的调控fimXY基因在菌毛形态发生中对fimA蛋白的表达起重要作用。fimR基因的产物是一种正调控因子，被发现与fimXY上游区域结合以产生菌毛蛋白。