• Korean Journal of Food Science and Technology
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• v.21 no.5
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• pp.669-675
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• 1989

Fresh mushroom (Agaricus bisporus L.) was irradiated (0, 1, 2, 3kGy) and kept for 20 days at 9{\pm}1^{\circ}C\;and\;80{\pm}7%$ RH. Parameters of qualities were investigated on the physical and physiological characteristics. The pileus and stipe on nonirradiated mushroom were expanded and elongated from the 3rd day of storage, there by losing the acceptability as edible samples. After 5 days of storage, 2 to 3kGy of gamma irradiation were especially effective for controllong natural maturation and senescence of fresh mushrooms and so irradiated mushrooms were acceptable more than 20days storage. The texture of irradiated samples was superior to that of nonirradiated samples, even though softening of the tissue occurred during storage. Weight loss was greatest in the nonirradiated sample due to evaporation from an increased surface area resulting from expansion and ripending, which were retarded in the 2 to 3kGy irradiated samples after 5days of storage. These results suggest that the irradiation dose of 2 to 3kGy is apparently effective to extend the shelf life of fresh mushrooms stored at the above-mentioned condition.

• Toxicological Research
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• v.24 no.3
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• pp.175-182
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• 2008

DNA-dependent protein kinase(DNA-PK) is involved in joining DNA double-strand breaks induced by ionizing radiation or V(D)J recombination and is activated by DNA ends and composed of a DNA binding subunit, Ku, and a catalytic subunit, DNA-PKcs. It has been suggested that DNA-PK might be $2^{nd}$ upstream kinase for protein kinase B(PKB). In this report, we showed that Ser473 phosphorylation in the hydrophobic-motif of PKB is blocked in DNA-PK knockout mouse embryonic fibroblast cells(MEFs) following insulin stimulation, while there is no effect on Ser473 phosphorylation in DNA-PK wild type MEF cells. The observation is further confirmed in human glioblastoma cells expressing a mutant form of DNA-PK(M059J) and a wild-type of DNA-PK(M059K), indicating that DNA-PK is indeed important for PKB activation. Furthermore, the treatment of cells with doxorubicin, DNA-damage inducing agent, leads to PKB phosphorylation on Ser473 in control MEF cells while there is no response in DNA-PK knockout MEF cells. Together, these results proposed that DNA-PK has a potential role in insulin signaling as well as DNA-repair signaling pathway.