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101.
A yeast actin-binding protein is encoded by SAC6, a gene found by suppression of an actin mutation 总被引:31,自引:0,他引:31
The protein encoded by SAC6, a gene that can mutate to suppress a temperature-sensitive defect in the yeast actin gene, has been identified as a 67-kilodalton actin-binding protein (ABP 67) that associates with all identifiable actin structures. This finding demonstrates the in vivo functional importance of the actin-ABP 67 interaction previously established in vitro and illustrates the use of suppressor analysis to identify physically interacting proteins. 相似文献
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Transgenic models of tumor development 总被引:33,自引:0,他引:33
Numerous cancer-prone strains of mice have been created by the introduction of candidate tumor-promoting genes into fertilized eggs. Each transgenic strain is predisposed to develop specific types of tumors, but they usually arise stochastically because of the need for spontaneous mutation of genes that collaborate with the introduced oncogene. These mice are providing insights into the effects of individual oncogenes on cellular proliferation, differentiation, and viability, as well as on oncogene cooperativity. Their predisposed state imposes sensitivity to viral and chemical carcinogenesis, and the mice should prove valuable in tests of potential carcinogens, therapies, and preventive measures. 相似文献
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T L Doering J Raper L U Buxbaum S P Adams J I Gordon G W Hart P T Englund 《Science (New York, N.Y.)》1991,252(5014):1851-1854
Trypanosoma brucei, the protozoan parasite responsible for African sleeping sickness, evades the host immune response through the process of antigenic variation. The variant antigen, known as the variant surface glycoprotein (VSG), is anchored to the cell surface by a glycosyl phosphatidylinositol (GPI) structure that contains myristate (n-tetradecanoate) as its only fatty acid component. The utilization of heteroatom-containing analogs of myristate was studied both in a cell-free system and in vivo. Results indicated that the specificity of fatty acid incorporation depends on chain length rather than on hydrophobicity. One analog, 10-(propoxy)decanoic acid, was highly toxic to trypanosomes in culture although it is nontoxic to mammalian cells. 相似文献
108.
The energy content of the mycoparasite Sporidesmium sclerotivorum mycelium was 18,389 J g?1 and 16,334 J g?1 for macroconidia on a dry weight basis. The energy content of Sclerotinia minor sclerotia, the host of the mycoparasite, was 16,485 J g?1. In liquid culture, the economic coefficient for the conversion of glucose to mycelium (mycelial dry wt ÷ glucose consumed × 100) was 51–60 whereas the mycelial energy coefficient, [mycelial energy (J) ÷ substrate energy (J) × 100] was 65–75. In soil, the conidial energy coefficient [conidial energy (J) ÷ substrate energy (J) × 100] for the conversion of host sclerotial energy to the macroconidia of the mycoparasite was 19.8, which was 2–9 times that for the conversion of glucose in liquid culture. The conidial energy coefficient when grown on a liquid medium on vermiculite was 23.0. S. sclerotivorum, as an obligate parasite of sclerotia in soil, was most efficient in the conversion of energy in a system where there was a high surface: energy ratio. In liquid culture S. sclerotivorum is more efficient than most other fungi. 相似文献
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Biological thiols are important antioxidants, and recent studies showed that their contents vary depending on the groups of foodstuffs. Therefore, we investigated the levels of some biological thiols in various vegetables and fruits by using a sensitive high-performance liquid chromatography (HPLC) technique. Biological thiols measured in some vegetables and fruits include glutathione (L-glutamyl-L-cysteinly glycine, GSH), N-acetylcysteine (NAC), captopril [CAP (C9H15NO3S)], homocysteine (HCYS), cysteine (CYS), and gamma-glutamyl cysteine (GGC). Our results show that biological thiol contents are between 3-349 nM/g wet weight in vegetables and 4-136 nM/g wet weight in fruits. CAP is only found in asparagus (28 nM/g wet weight). Furthermore, none of the biological thiols analyzed were found in cabbages, red grapes, blackberries, apples, and peaches. Therefore, various vegetables and fruits differ significantly in their thiol contents. Oxidation of these important thiols may occur and result in the production of toxic byproducts, if they are exposed to radiation and ozone treatment for sterilization purposes. Further studies should be performed to monitor the levels of these biological thiols. 相似文献