SPECIFIC AND HIGH-AFFINITY BINDING OF INOSITOL PHOSPHATES TO AN ISOLATED PLECKSTRIN HOMOLOGY DOMAIN
SPECIFIC AND HIGH-AFFINITY BINDING OF INOSITOL PHOSPHATES TO AN ISOLATED PLECKSTRIN HOMOLOGY DOMAIN
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DOI：
10.1073/pnas.92.23.10472
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发表时间：
1995-11-07
影响因子：
11.1
通讯作者：
SCHLESSINGER, J
中科院分区：
文献类型：
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作者：
LEMMON, MA;FERGUSON, KM;SCHLESSINGER, J
Pleckstrin 同源 (PH) 结构域存在于许多信号分子中，并且被认为参与特定的分子间相互作用。据报道，它们与多种蛋白质和含有 1-α-磷脂酰肌醇 4,5-二磷酸 [PtdIns(4,5)P-2] 的膜结合，包含 PH 结构域的区域也涉及磷脂酶 C-delta(1) (PLC-delta(1)) 与 PtdIns(4,5)P-2 和 D-myo-肌醇的结合 1,4,5-三磷酸盐 [Ins(1,4,5)P-3] [Cifuentes, M. E., Delaney, T.& Rebecchi, M. J. (1994) J. Biol。化学。 269，1945-1948]。我们在此报告，从 PLC-delta(1) 分离的 PH 结构域以高亲和力结合 PtdIns(4,5)P-2 和 Ins(1,4,5)P-3，并显示出与其他完整 PLC-delta(1) 相同的结合特异性。因此，PH 域在功能和结构上都是模块化的。这些结果证明了分离的 PH 结构域的立体特异性高亲和力结合，并进一步支持 PH 结构域在 PLC 同工型调节中的功能作用。其他 PH 结构域并未与测试的化合物牢固结合，表明肌醇磷酸盐和磷脂不太可能是所有 PH 结构域的生理配体。尽管如此，由于所有含有 PH 结构域的蛋白质都与膜表面相关，多个 PH 结构域与膜上的特定位点结合，并且 PH 结构域似乎是静电极化的，因此表明 PH 结构域在膜结合中可能发挥一般作用。
Pleckstrin homology (PH) domains are found in many signaling molecules and are thought to be involved in specific intermolecular interactions. Their binding to several proteins and to membranes containing 1-alpha-phosphatidylinositol 4,5-bisphosphate [PtdIns(4,5)P-2] has been reported, A region that includes the PH domain has also been implicated in binding of phospholipase C-delta(1) (PLC-delta(1)) to both PtdIns(4,5)P-2 and D-myo-inositol 1,4,5-trisphosphate [Ins(1,4,5)P-3] [Cifuentes, M. E., Delaney, T.& Rebecchi, M. J. (1994) J. Biol. Chem. 269, 1945-1948]. We report herein that the isolated PH domain from PLC-delta(1) binds to both PtdIns(4,5)P-2 and Ins(1,4,5)P-3 with high affinity and shows the same binding specificity seen by others with whole PLC-delta(1). Thus the PH domain is functionally and structurally modular. These results demonstrate stereo-specific high-affinity binding by an isolated PH domain and further support a functional role for PH domains in the regulation of PLC isoforms. Other PH domains did not bind strongly to the compounds tested, suggesting that inositol phosphates and phospholipids are not likely physiological ligands for all PH domains. Nonetheless, since all PH-domain-containing proteins are associated with membrane surfaces, several PH domains bind to specific sites on membranes, and PH domains appear to be electrostatically polarized, a possible general role for PH domains in membrane association is suggested.