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Won Tae Kim Hee Jung Choi Yunwoong Park A-young Kim Young Ho Kim Jongbok Seo Si Hyeock Lee Young Ho Koh 《Journal of Asia》2010,13(4):339-343
Presenilins are one of two types of critical genetic factors in familial Alzheimer's disease, and they regulate various cellular functions such as intracellular Ca2+ homeostasis, the endoplasmic reticulum (ER) stress response, apoptosis, and synaptic transmission. We utilized Drosophila presenilin (psn) mutants as a model for studying the role of this gene in regulating acetylcholinesterase activity (AChE) and synaptic plasticity. Several lines of biochemical evidence indicated that AChE activity in a functionally null psn mutant (psnB3) was significantly reduced. In addition, we also found that psnB3 mutant neuromuscular junctions (NMJs) had smaller synaptic boutons and altered localization of Discs large, a synaptic scaffolding protein at the synaptic terminals compared to wild-type controls. These phenotypic defects were completely rescued in transgenic lines expressing the long form of wild-type Psn under an endogenous psn promoter cassette (PEPC-PsnWT;psnB3 lines). Taken together, these results indicate that Psn is important for regulating AChE activity, the size of synaptic boutons, and the localization of DLG at synaptic terminals. 相似文献
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Purified malformin A1 (cyclo-D-Cys-D-Cys-L-Val-D-Leu-L-lle), a cyclicpentapeptide toxin fromAspergillus niger, was applied to the hypocotyl segments of mung bean (Vigna radiata L.) seedlings to investigate its role in regulating ethylene biosynthesis. Production of ethylene was induced by treating
the plants with 0.1 mM indole-3-acetic acid (1AA). When 0.1 μM malformin A1 was then applied, ethylene production increased
and the activities of two key enzymes for its biosynthesis, 1-aminocyclopropane-1-carboxylic acid (ACC)-synthase (ACS) and
ACC-oxidase (ACO), were also stimulated. However, at levels of 1 or 10 μM malformin A1, both ethylene production and enzymatic
activities were significantly reduced. In the case of ACO,in vitro activity was regulated by malformin A1, independent of ACS activity or the influence of IAA. Furthermore, the conjugate form
of ACC, N-malonyl ACC, was significantly promoted by treatment with 0.1 μM malformin A1. These data suggest that malformin
A1 can modulate ethylene production through diverse paths and that its effect depends on the concentration of the treatment
administered. 相似文献
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