A single amino acid exchange inverts susceptibility of related receptor tyrosine kinases for the ATP site inhibitor STI-571
A single amino acid exchange inverts susceptibility of related receptor tyrosine kinases for the ATP site inhibitor STI-571
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DOI：
10.1074/jbc.m209861200
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发表时间：
2003-02-14
影响因子：
4.8
通讯作者：
Dove, S
中科院分区：
文献类型：
--
作者：
Böhmer, FD;Karagyozov, L;Dove, S
酪氨酸激酶抑制剂 STI-571 有效阻断 BCR-Abl、血小板衍生生长因子 (PDGF) α 和 β 受体以及 c-Kit 激酶活性。 Flt3 是一种与 PDGF 受体和 c-Kit 密切相关的受体酪氨酸激酶，但不受 STI-571 抑制。不同激酶的序列比对和 STI-571 Abl 激酶复合物晶体结构的指示揭示了可能对该活性谱至关重要的氨基酸残基。据预测，135 链中的 Flt3 Phe-691 可能在空间上阻止与 STI-571 的相互作用。构建了点突变体 Flt3 F691T 和 PDGFbeta 受体 T681F，激酶测定表明 STI-571 抑制 Flt3 突变体，但不抑制 PDGFbeta 受体突变体。将 STI-571 对接到 PDGFbeta 受体和 Flt3 激酶结构域的计算机模型中，并与 STI-571 Abl 激酶复合物的晶体结构进行比较，表明三种非磷酸化激酶之间的结合位点非常相似，表明它们的 Asp-Phe-Gly 基序和激活环的相应过程。因此，我们观察到与未激活的 PDGFR-β 相比，预激活的 PDGFR-β 对 STI-571 抑制的敏感性降低。与 STI-571 结合相冲突的激活环过程解释了它在胰岛素受体等其他激酶上的失活。 PDGFR-β 和 Flt3 的结合位点模型用于预测更具选择性的 PDGFβ 受体抑制剂的结构方法。
The tyrosine kinase inhibitor STI-571 potently blocks BCR-Abl, platelet-derived growth factor (PDGF) alpha- and beta-receptors, and c-Kit kinase activity. Flt3, a receptor tyrosine kinase closely related to PDGF receptors and c-Kit is, however, not inhibited by STI-571. Sequence alignments of different kinases and indications from the crystal structure of the STI-571 Abl kinase complex revealed amino acid residues that are probably crucial for this activity profile. It was predicted that Flt3 Phe-691 in the 135 strand may sterically prevent interaction with STI-571. The point mutants Flt3 F691T and PDGFbeta-receptor T681F were constructed, and kinase assays showed that the Flt3 mutant but not the PDGFbeta-receptor mutant is inhibited by STI-571. Docking of STI-571 into computer models of the PDGFbeta-receptor and Flt3 kinase domains and comparison with the crystal structure of the STI-571 Abl kinase complex indicated very similar binding sites among the three nonphosphorylated kinases, suggesting corresponding courses of their Asp-Phe-Gly motifs and activation loops. Accordingly, we observed reduced sensitivity of preactivated compared with nonactivated PDGFR-beta for the inhibition by STI-571. Courses of the activation loop that collide with STI-571 binding explain its inactivity at other kinases as the insulin receptor. The binding site models of PDGFR-beta and Flt3 were applied to predict structural approaches for more selective PDGFbeta-receptor inhibitors.