Hayashi Makoto, Nito Kazumasa, Takei-Hoshi Rie, Yagi Mina, Kondo Maki, Suenaga Arata, Yamaya Tomoyuki, Nishimura Mikio
Department of Cell Biology, National Institute for Basic Biology, Okazaki, 444-8585 Japan.
Plant Cell Physiol. 2002 Jan;43(1):1-11. doi: 10.1093/pcp/pcf023.
Glyoxysomes, a group of specialized peroxisomes, are organelles that degrade fatty acids by the combination of fatty acid beta-oxidation and glyoxylate cycle. However, the mechanism underlying the transport of the fatty acids across the peroxisomal membrane is still obscure in higher plant cells. We identified and analyzed the PED3 gene and its gene product, Ped3p. The phenotype of the Arabidopsis ped3 mutant indicated that the mutation in the PED3 gene inhibits the activity of fatty acid beta-oxidation. Ped3p is a 149-kDa protein that exists in peroxisomal membranes. The amino acid sequence of Ped3p had a typical characteristic for "full-size" ATP-binding cassette (ABC) transporter consisting of two transmembrane regions and two ATP-binding regions. This protein was divided into two parts, that had 32% identical amino acid sequences. Each part showed a significant sequence similarity with peroxisomal "half" ABC transporters so far identified in mammals and yeast. Ped3p may contribute to the transport of fatty acids and their derivatives across the peroxisomal membrane.
乙醛酸循环体是一类特殊的过氧化物酶体，是通过脂肪酸β-氧化和乙醛酸循环相结合来降解脂肪酸的细胞器。然而，在高等植物细胞中，脂肪酸跨过氧化物酶体膜运输的潜在机制仍不清楚。我们鉴定并分析了PED3基因及其基因产物Ped3p。拟南芥ped3突变体的表型表明，PED3基因的突变抑制了脂肪酸β-氧化的活性。Ped3p是一种存在于过氧化物酶体膜中的149 kDa蛋白。Ped3p的氨基酸序列具有典型的“全尺寸”ATP结合盒（ABC）转运蛋白特征，由两个跨膜区域和两个ATP结合区域组成。该蛋白分为两部分，其氨基酸序列有32%相同。每一部分与迄今在哺乳动物和酵母中鉴定出的过氧化物酶体“半”ABC转运蛋白都有显著的序列相似性。Ped3p可能有助于脂肪酸及其衍生物跨过上氧化物酶体膜的运输。
