Function of the PEX19-binding site of human adrenoleukodystrophy protein as targeting motif in man and yeast - PMP targeting is evolutionarily conserved
Function of the PEX19-binding site of human adrenoleukodystrophy protein as targeting motif in man and yeast - PMP targeting is evolutionarily conserved
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DOI：
10.1074/jbc.m501750200
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发表时间：
2005-06-03
影响因子：
4.8
通讯作者：
Rottensteiner, H
中科院分区：
文献类型：
--
作者：
Halbach, A;Lorenzen, S;Rottensteiner, H
我们预测在人类过氧化物酶体膜蛋白（PMP）的结合位点PEX19，一个关键的球员在拓扑结构的PMPs，凭借酵母PMP开发的算法。最佳评分的PEX19结合位点被发现在肾上腺脑白质营养不良蛋白（ALDP）。所鉴定的位点确实被人PEX19结合，并且也被酵母PEX19蛋白识别。同样，人和酵母PEX19都以相当的亲和力结合酵母PMP Pex13p的PEX19结合位点。有趣的是，ALDP的PEX19结合位点与其先前确定的靶向基序一致。我们证实了人成纤维细胞中过氧化物酶体靶向ALDP PEX19结合位点的要求，并表明最小ALDP片段也以PEX19结合位点依赖性方式正确靶向酵母。此外，在体内靶向测定中，ALDP的人PEX19结合位点证明与酵母Pex13 p的结合位点可互换。最后，我们在体外表明，大多数预测的人类PMPs的结合序列代表人类PEX19的真正结合位点，表明人类PMPs具有与酵母相似的共同PEX19结合位点。我们的数据清楚地揭示了PEX19结合位点作为跨物种的PMP靶向基序的作用，从而证明了PMP信号序列从酵母到人的进化保守性。
We predicted in human peroxisomal membrane proteins (PMPs) the binding sites for PEX19, a key player in the topogenesis of PMPs, by virtue of an algorithm developed for yeast PMPs. The best scoring PEX19-binding site was found in the adrenoleukodystrophy protein ( ALDP). The identified site was indeed bound by human PEX19 and was also recognized by the orthologous yeast PEX19 protein. Likewise, both human and yeast PEX19 bound with comparable affinities to the PEX19- binding site of the yeast PMP Pex13p. Interestingly, the identified PEX19- binding site of ALDP coincided with its previously determined targeting motif. We corroborated the requirement of the ALDP PEX19-binding site for peroxisomal targeting in human fibroblasts and showed that the minimal ALDP fragment targets correctly also in yeast, again in a PEX19-binding site-dependent manner. Furthermore, the human PEX19-binding site of ALDP proved interchangeable with that of yeast Pex13p in an in vivo targeting assay. Finally, we showed in vitro that most of the predicted binding sequences of human PMPs represent true binding sites for human PEX19, indicating that human PMPs harbor common PEX19-binding sites that do resemble those of yeast. Our data clearly revealed a role for PEX19- binding sites as PMP-targeting motifs across species, thereby demonstrating the evolutionary conservation of PMP signal sequences from yeast to man.