Existence of catalase-less peroxisomes in Sf21 insect cells
Existence of catalase-less peroxisomes in Sf21 insect cells
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DOI：
10.1016/s0006-291x(03)00913-6
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发表时间：
2003-06-20
影响因子：
3.1
通讯作者：
Imanaka, T
中科院分区：
文献类型：
--
作者：
Kurisu, M;Morita, M;Imanaka, T
过氧化氢酶活性（一种过氧化物酶体标记酶）在草地贪夜蛾 (Sf) 21 昆虫细胞的任何亚细胞级分中均未检测到，尽管其他细胞器中的标记酶以与哺乳动物细胞中相似的方式分布在这些级分中。当C端与过氧化物酶体靶向信号1融合的绿色荧光蛋白（GFP-SKL）在Sf21细胞中表达时，在细胞质中观察到点状荧光点。 GFP-SKL浓缩的级分在KCN存在下表现出长链和极长链脂肪酸β-氧化活性，并且该级分的密度略高于线粒体的密度。使用抗 SKL 抗体进行的免疫电镜研究表明，Sf21 细胞具有免疫反应性过氧化物酶体样细胞器，其结构与线粒体、内质网和溶酶体不同。与过氧化物酶体基质蛋白相反，肾上腺脑白质营养不良蛋白（一种过氧化物酶体膜蛋白）不定位于过氧化物酶体。这表明昆虫细胞中 PMP 的靶向信号与哺乳动物细胞中的不同。这些结果表明，Sf21 昆虫细胞具有独特的无过氧化氢酶过氧化物酶体，能够对脂肪酸进行 β 氧化。 (C) 2003 年爱思唯尔科学（美国）。版权所有。
Catalase activity, a peroxisomal marker enzyme, was not detectable in any of the subcellular fractions of Spodoptera frugiperda (Sf) 21 insect cells, although marker enzymes in other organelles were distributed in the fractions in a manner similar to that seen in mammalian cells. When a green fluorescent protein fused with peroxisome targeting signal 1 at the C-terminal (GFP-SKL) was expressed in Sf21 cells, punctate fluorescent dots were observed in the cytoplasm. The fraction where GFP-SKL was concentrated exhibited long-chain and very-long-chain fatty acid beta-oxidation activities in the presence of KCN and the density of this fraction was slightly higher than that of mitochondria. Immunoelectron microscopy studies with anti-SKL antibody demonstrated that Sf21 cells have immunoreactive peroxisome-like organelles which are structurally distinct from mitochondria, endoplasmic reticulum, and lysosomes. In contrast to peroxisomal matrix proteins, adrenoleukodystrophy protein, a peroxisomal membrane protein, was not located to peroxisomes. This suggests that the targeting signal for PMP in insect cells is distinct from that in mammalian cells. These results demonstrate that Sf21 insect cells have unique catalase-less peroxisomes capable of beta-oxidation of fatty acids. (C) 2003 Elsevier Science (USA). All rights reserved.