The peroxisomal membrane targeting elements of human peroxin 2 (PEX2).
The peroxisomal membrane targeting elements of human peroxin 2 (PEX2).
复制标题
过氧化物酶体膜靶向人过氧化物酶 2 (PEX2) 元件。
DOI：
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发表时间：
2003
影响因子：
6.6
通讯作者：
J. Gärtner
中科院分区：
文献类型：
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作者：
M. Biermanns;J. von Laar;U. Brosius;J. Gärtner
过氧化物酶2（PEX 2）是一种35 kDa的过氧化物酶体膜蛋白，具有两个跨膜区和一个锌环结构域。虽然它在过氧化物酶体生物发生和功能中的作用知之甚少，但它似乎参与过氧化物酶体基质蛋白的输入。PEX 2在游离的胞质核糖体上合成，并通过特异性靶向信息后向输入过氧化物酶体膜。虽然过氧化物酶体基质蛋白的基本靶向机制在过去几年中已经出现了一个清晰的画面，过氧化物酶体膜蛋白的靶向过程还不太清楚。我们在COS-7细胞中表达了与绿色荧光蛋白融合的PEX 2的各种缺失构建体，并确定了它们的细胞内定位。我们发现人PEX 2的最小过氧化物酶体靶向信号由30个氨基酸的内部蛋白区域（AA 130至AA 159）和第一跨膜结构域组成，并且添加第二跨膜结构域增加靶向效率。在最小靶向区域内，我们鉴定了基序“KX 6（I/L）X（L/F/I）LK（L/F/I）”，其包括重要的靶向信息，并且也存在于22-kDa过氧化物酶体膜蛋白（PMP 22）和70-kDa过氧化物酶体膜蛋白（PMP 70）的靶向区域中。该靶向基序中的突变将PEX 2错误定位于细胞溶质。相反，第二跨膜结构域似乎不具有特异性过氧化物酶体膜靶向信息。用人细胞色素c氧化酶亚基IV的跨膜结构域替换人PEX 2的第二跨膜结构域不改变PEX 2过氧化物酶体靶向功能和效率。
Peroxin 2 (PEX2) is a 35-kDa integral peroxisomal membrane protein with two transmembrane regions and a zinc RING domain within its cytoplasmically exposed C-terminus. Although its role in peroxisome biogenesis and function is poorly understood, it seems to be involved in peroxisomal matrix protein import. PEX2 is synthesized on free cytosolic ribosomes and is posttranslationally imported into the peroxisome membrane by specific targeting information. While a clear picture of the basic targeting mechanisms for peroxisomal matrix proteins has emerged over the past years, the targeting processes for peroxisomal membrane proteins are less well understood. We expressed various deletion constructs of PEX2 in fusion with the green fluorescent protein in COS-7 cells and determined their intracellular localization. We found that the minimum peroxisomal targeting signal of human PEX2 consists of an internal protein region of 30 amino acids (AA130 to AA159) and the first transmembrane domain, and that adding the second transmembrane domain increases targeting efficiency. Within the minimum targeting region we identified the motif "KX6(I/L)X(L/F/I)LK(L/F/I)" that includes important targeting information and is also present in the targeting regions of the 22-kDa peroxisomal membrane protein (PMP22) and the 70-kDa peroxisomal membrane protein (PMP70). Mutations in this targeting motif mislocalize PEX2 to the cytosol. In contrast, the second transmembrane domain does not seem to have specific peroxisomal membrane targeting information. Replacing the second transmembrane domain of human PEX2 with the transmembrane domain of human cytochrome c oxidase subunit IV does not alter PEX2 peroxisome targeting function and efficiency.
Pex17p 是过氧化物酶体膜和腔蛋白输入所必需的，并与毕赤酵母中的 Pex19p 和过氧化物酶体靶向信号受体对接复合物相互作用。
影响因子：
3.3
作者：
Snyder,WB;Koller,A;Choy,AJ;Johnson,MA;Cregg,JM;Rangell,L;Keller,GA;Subramani,S
通讯作者：
Subramani,S