Insertion of Pex5p into the peroxisomal membrane is cargo protein-dependent
Insertion of Pex5p into the peroxisomal membrane is cargo protein-dependent
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DOI：
10.1074/jbc.c200650200
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发表时间：
2003-02-14
影响因子：
4.8
通讯作者：
Azevedo, JE
中科院分区：
文献类型：
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作者：
Gouveia, AM;Guimaraes, CP;Azevedo, JE
现在普遍认为，大多数过氧化物酶体基质蛋白的受体Pex5p在细胞质和过氧化物酶体间室之间循环。根据目前的过氧化物酶体生物发生模型，Pex5p的细胞内运输与新合成的过氧化物酶体蛋白转运到细胞器基质相结合。然而;支持这一假设的直接证据从未被提供。在这里，使用体外过氧化物酶体导入系统，我们发现Pex5p插入过氧化物酶体膜需要货物蛋白的存在。引人注目的是，过氧化物酶体对接易位机制也能够催化缺乏任何已知货物结合结构域的Pex5p截断分子的膜插入。这些结果表明，Pex5p参与的细胞质/过氧化物酶体循环是由Pex5p本身直接或间接调节的，而不是由过氧化物酶体对接/易位机制调节的。
It is now generally accepted that Pex5p, the receptor for most peroxisomal matrix proteins, cycles between the cytosol and the peroxisomal compartment. According to current models of peroxisomal biogenesis, this intracellular trafficking of Pex5p is coupled to the transport of newly synthesized peroxisomal proteins into the organelle matrix. However; direct evidence supporting this hypothesis was never provided. Here, using an in vitro peroxisomal import system, we show that insertion of Pex5p into the peroxisomal membrane requires the presence of cargo proteins. Strikingly the peroxisomal docking translocation machinery is also able to catalyze the membrane insertion of a Pex5p truncated molecule lacking any known cargo-binding domain. These results suggest that the cytosol/peroxisomal cycle in which Pex5p is involved is directly or indirectly regulated by Pex5p itself and not by the peroxisomal docking/translocation machinery.