Phosphoinositide-binding peptides derived from the sequences of gelsolin and villin.
Phosphoinositide-binding peptides derived from the sequences of gelsolin and villin.
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DOI：
10.1016/s0021-9258(19)49772-x
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发表时间：
1992
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影响因子：
--
通讯作者：
P. Janmey;J. Lamb;P. G. Allen;P. Matsudaira
中科院分区：
文献类型：
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作者：
P. Janmey;J. Lamb;P. G. Allen;P. Matsudaira
磷脂酰肌醇4-单磷酸（PIP）和磷脂酰肌醇4,5-二磷酸（PIP2）灭活肌动蛋白丝切断蛋白绒毛蛋白和凝胶蛋白，并将它们与单体和聚合肌动蛋白分离。人血浆凝胶蛋白调节纤维断裂的多磷酸肌苷（PPI）的潜在结合位点定位于残基150-169之间的区域和绒毛蛋白中相应的区域，绒毛蛋白位于这两种蛋白中存在的6个同源结构域中的第二个区域。基于这些序列的合成肽在胶束或双层囊泡中与PIP和PIP2紧密结合，与凝胶竞争与PPIs结合，并解离凝胶-PIP2复合物，恢复蛋白质的切断活性。这些肽还以中等亲和力结合f -肌动蛋白，这表明PPIs对完整蛋白的切断功能失活是由于肌动蛋白和PPIs对凝胶-绒毛蛋白上的关键结合位点的竞争。ppi结合肽含有大量的碱性氨基酸，但它们对ppi的影响远远大于Arg或Lys寡聚物，这是一种高碱性肽，来自豆芽糖酰化的钙调素结合位点，富含丙氨酸的激酶C底物蛋白，或5-kDa肌动蛋白结合蛋白胸腺肽β -4，这表明这些碱性肽的一级和二级结构的特定方面对于它们与ppi的酸性头基团相互作用是重要的。除了阐明凝胶中pip2结合位点的结构外，研究结果还描述了一种基于磷酸肌醇结合分子防止凝胶蛋白功能抑制能力的敏感检测方法。
The polyphosphoinositides phosphatidylinositol 4-monophosphate (PIP) and phosphatidylinositol 4,5-bisphosphate (PIP2) inactivate the actin filament-severing proteins villin and gelsolin and dissociate them from monomeric and polymeric actin. A potential polyphosphoinositide- (PPI) binding site of human plasma gelsolin regulating filament severing has been localized to the region between residues 150-169 and to the corresponding region in villin which occurs in the second of six homologous domains present in both proteins. Synthetic peptides based on these sequences bind tightly to both PIP and PIP2, in either micelles or bilayer vesicles, compete with gelsolin for binding to PPIs, and dissociate gelsolin-PIP2 complexes, restoring severing activity to the protein. These peptides also bind with moderate affinity to F-actin, suggesting that inactivation of the severing function of the intact proteins by PPIs results from competition between actin and PPIs for a critical binding site on gelsolin-villin. The PPI-binding peptides contain numerous basic amino acids, but their effects on PPIs are far greater than those of Arg or Lys oligomers, a highly basic peptide derived from the calmodulin-binding site of myristoylated, alanine-rich kinase C substrate protein, or the 5-kDa actin-binding protein thymosin beta-4, suggesting that specific aspects of the primary and secondary structure of these basic peptides are important for their interaction with the acidic headgroups of PPIs. In addition to elucidating the structure of PIP2-binding sites in gelsolin, the results describe a sensitive assay for phosphoinositide-binding molecules based on their ability to prevent inhibition of gelsolin function.