PEX12 interacts with PEX5 and PEX10 and acts downstream of receptor docking in peroxisomal matrix protein import.
PEX12 interacts with PEX5 and PEX10 and acts downstream of receptor docking in peroxisomal matrix protein import.
复制标题
PEX12 与 PEX5 和 PEX10 相互作用，并在过氧化物酶体基质蛋白输入中的受体对接下游发挥作用。
DOI：
10.1083/jcb.147.4.761
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发表时间：
1999-11-15
期刊：
影响因子：
--
通讯作者：
Gould SJ
中科院分区：
文献类型：
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作者：
Chang CC;Warren DS;Sacksteder KA;Gould SJ
过氧化体基质蛋白的输入需要PEX12，它是一种完整的过氧化体膜蛋白，其羧基末端有一个锌环结构域。人类PEX12基因突变导致Zellweger综合征，这是一种致命的神经疾病，并涉及PEX12功能中的锌环结构域。通过双杂交研究、印迹重叠分析和免疫共沉淀实验，我们观察到PEX12的锌结合结构域结合了PTS1受体PEX5和PEX10，PEX10是另一种完整的过氧体膜蛋白，是过氧体基质蛋白输入所必需的。此外，我们还鉴定了一位PEX12锌结合结构域S320F错义突变的患者，并观察到该突变降低了PEX12与PEX5和PEX10的结合。PEX5或PEX10的过表达可以抑制这种PEX12突变，提供了这些相互作用具有生物学相关性的遗传证据。PEX5是一种主要的细胞质蛋白，以前的PEX5结合蛋白被认为与PEX5对接到过氧化物酶体表面。然而，我们发现PEX12或PEX10的缺失并不减少PEX5与过氧化物体的联系，这表明这些过氧物不是受体对接所必需的。这些和其他结果导致我们认为PEX12和PEX10在受体对接事件下游的过氧化体基质蛋白输入中起直接作用。
Peroxisomal matrix protein import requires PEX12, an integral peroxisomal membrane protein with a zinc ring domain at its carboxy terminus. Mutations in human PEX12 result in Zellweger syndrome, a lethal neurological disorder, and implicate the zinc ring domain in PEX12 function. Using two-hybrid studies, blot overlay assays, and coimmunoprecipitation experiments, we observed that the zinc-binding domain of PEX12 binds both PEX5, the PTS1 receptor, and PEX10, another integral peroxisomal membrane protein required for peroxisomal matrix protein import. Furthermore, we identified a patient with a missense mutation in the PEX12 zinc-binding domain, S320F, and observed that this mutation reduces the binding of PEX12 to PEX5 and PEX10. Overexpression of either PEX5 or PEX10 can suppress this PEX12 mutation, providing genetic evidence that these interactions are biologically relevant. PEX5 is a predominantly cytoplasmic protein and previous PEX5-binding proteins have been implicated in docking PEX5 to the peroxisome surface. However, we find that loss of PEX12 or PEX10 does not reduce the association of PEX5 with peroxisomes, demonstrating that these peroxins are not required for receptor docking. These and other results lead us to propose that PEX12 and PEX10 play direct roles in peroxisomal matrix protein import downstream of the receptor docking event.