The PLAC1-homology region of the ZP domain is sufficient for protein polymerisation
The PLAC1-homology region of the ZP domain is sufficient for protein polymerisation
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DOI：
10.1186/1471-2091/7/11
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发表时间：
2006-04-06
期刊：
影响因子：
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通讯作者：
Wassarman, Paul M.
中科院分区：
文献类型：
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作者：
Jovine, Luca;Janssen, William G.;Wassarman, Paul M.
背景：数百种细胞外蛋白通过使用透明带 (ZP) 结构域聚合成丝和基质。 ZP 结构域蛋白执行高度多样化的功能，从结构到受体，其基因突变导致许多严重的人类疾病。最近，PLAC1、Oosp1-3、Papillote 和 CG16798 蛋白被鉴定与 ZP 结构域的 N 端半部 (ZP-N) 具有序列同源性，但与其 C 端半部 (ZP-C) 不具有序列同源性。这种部分保守的功能意义尚不清楚。结果：通过利用高度工程化的细菌菌株，我们以可溶形式表达哺乳动物精子受体 ZP3 的 PLAC1 同源区域，作为与麦芽糖结合蛋白的融合体。质谱分析表明，融合蛋白 ZP-N 部分内的 4 个保守的 Cys 残基采用与全长天然 ZP3 相同的二硫键连接，表明它正确折叠，电子显微镜和生化分析表明它组装成丝状。结论：这些发现为 PLAC1 样蛋白提供了功能，并通过表明 ZPN 是一种生物活性折叠单位，促使重新评估 ZP 结构域的结构和它的聚合物。此外，他们认为 ZP-C 可能在 ZP 结构域蛋白复合物的组装中发挥调节作用。
Background: Hundreds of extracellular proteins polymerise into filaments and matrices by using zona pellucida (ZP) domains. ZP domain proteins perform highly diverse functions, ranging from structural to receptorial, and mutations in their genes are responsible for a number of severe human diseases. Recently, PLAC1, Oosp1-3, Papillote and CG16798 proteins were identified that share sequence homology with the N-terminal half of the ZP domain (ZP-N), but not with its C-terminal half (ZP-C). The functional significance of this partial conservation is unknown.Results: By exploiting a highly engineered bacterial strain, we expressed in soluble form the PLAC1-homology region of mammalian sperm receptor ZP3 as a fusion to maltose binding protein. Mass spectrometry showed that the 4 conserved Cys residues within the ZP-N moiety of the fusion protein adopt the same disulfide bond connectivity as in full-length native ZP3, indicating that it is correctly folded, and electron microscopy and biochemical analyses revealed that it assembles into filaments.Conclusion: These findings provide a function for PLAC1-like proteins and, by showing that ZPN is a biologically active folding unit, prompt a re-evaluation of the architecture of the ZP domain and its polymers. Furthermore, they suggest that ZP-C might play a regulatory role in the assembly of ZP domain protein complexes.