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外文期刊>The biochemical journal
>Crystal structure of the phosphatidylinositol 3,4-bisphosphate-binding pleckstrin homology (PH) domain of tandem PH-domain-containing protein 1 (TAPP1): molecular basis of lipid specificity
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Crystal structure of the phosphatidylinositol 3,4-bisphosphate-binding pleckstrin homology (PH) domain of tandem PH-domain-containing protein 1 (TAPP1): molecular basis of lipid specificity
pPhosphatidylinositol 3,4,5-trisphosphate [PtdIns(3,4,5)iP/isub3/sub] and its immediate breakdown product PtdIns(3,4)iP/isub2/sub function as second messengers in growth factor- and insulin-induced signalling pathways. One of the ways that these 3-phosphoinositides are known to regulate downstream signalling events is by attracting proteins that possess specific PtdIns-binding pleckstrin homology (PH) domains to the plasma membrane. Many of these proteins, such as protein kinase B, phosphoinositide-dependent kinase 1 and the bd/bual ba/bdaptor for bp/bhosphotyrosine and 3-bp/bhosphoinositides (DAPP1) interact with both PtdIns(3,4,5)iP/isub3/sub and PtdIns(3,4)iP/isub2/sub with similar affinity. Recently, a new PH-domain-containing protein, termed bta/bndem bP/bH-domain-containing bp/brotein (TAPP) 1, was described which is the first protein reported to bind PtdIns(3,4)iP/isub2/sub specifically. Here we describe the crystal structure of the PtdIns(3,4)iP/isub2/sub-binding PH domain of TAPP1 at 1.4 ? (1 ? = 0.1 nm) resolution in complex with an ordered citrate molecule. The structure is similar to the known structure of the PH domain of DAPP1 around the D-3 and D-4 inositol-phosphate-binding sites. However, a glycine residue adjacent to the D-5 inositol-phosphate-binding site in DAPP1 is substituted for a larger alanine residue in TAPP1, which also induces a conformational change in the neighbouring residues. We show that mutation of this glycine to alanine in DAPP1 converts DAPP1 into a TAPP1-like PH domain that only interacts with PtdIns(3,4)iP/isub2/sub, whereas the alanine to glycine mutation in TAPP1 permits the TAPP1 PH domain to interact with PtdIns(3,4,5)iP/isub3/sub./p
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机译:>磷脂酰肌醇3,4,5-三磷酸[PtdIns(3,4,5) P i> 3 sub>]及其直接分解产物PtdIns(3,4) P i> 2 sub>在生长因子和胰岛素诱导的信号通路中充当第二信使。已知这些3-磷酸肌醇调节下游信号传导事件的方式之一是通过将具有特定PtdIns结合pleckstrin同源性(PH)域的蛋白吸引到质膜上。这些蛋白质中有许多,例如蛋白激酶B,磷酸肌醇依赖性激酶1和 p b>正酪氨酸和3- < b> p b>磷酸肌苷(DAPP1)与PtdIns(3,4,5) P i> 3 sub>和PtdIns(3,4) P < / i> 2 sub>具有相似的相似性。最近,描述了一种新的含PH结构域的蛋白质,称为 ta b> ndem P b> H结构域的 p b>蛋白质(TAPP)1。据报道是第一个与PtdIns(3,4) P i> 2 sub>特异性结合的蛋白质。在这里,我们描述了TAPP1的PtdIns(3,4) P i> 2 sub>-结合PH域在1.4?的晶体结构。与有序的柠檬酸盐分子形成复杂的(1?= 0.1 nm)分辨率。该结构类似于DAPP1的PH结构域在D-3和D-4肌醇磷酸结合位点附近的已知结构。但是,DAPP1中与D-5肌醇-磷酸结合位点相邻的甘氨酸残基取代了TAPP1中较大的丙氨酸残基,这也引起了相邻残基的构象变化。我们显示,DAPP1中这种甘氨酸突变为丙氨酸可将DAPP1转换为仅与PtdIns(3,4) P i> 2 sub>相互作用的TAPP1样PH结构域,而丙氨酸TAPP1中的甘氨酸突变允许TAPP1 PH域与PtdIns(3,4,5) P i> 3 sub>相互作用。 p>
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