Crystal structures of the SH2 domain of Grb2: Highlight on the binding of a new high-affinity inhibitor
Crystal structures of the SH2 domain of Grb2: Highlight on the binding of a new high-affinity inhibitor
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DOI：
10.1006/jmbi.2001.5299
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发表时间：
2002-02-01
影响因子：
5.6
通讯作者：
Ducruix, A
中科院分区：
文献类型：
--
作者：
Nioche, P;Liu, WQ;Ducruix, A
生长因子受体的激活诱导其C末端酪氨酸残基的磷酸化，产生含有SH2结构域的蛋白的结合位点。Grb2是一种招募SOS的蛋白质，SOS是RAS的交换因子。SOS的招募允许RAS激活和随后的信号传输。这促进了MAP激酶移位到细胞核中，并激活了早期转录因子。Grb2是一个大小为25 kDa的蛋白质，由一个SH2结构域和两个SH3结构域组成。Grb2的SH2结构域通过共有序列pYXNX与第二类磷酸酪氨酸多肽结合。因此，Grb2是一个很好的例子，它使蛋白质接近，允许通过位于不同隔室的蛋白质进行信号转导。为了探索Grb2与磷酸化配体之间的相互作用，我们解决了Grb2-SH2结构域与Shc衍生序列对应的多肽之间的化合物的晶体结构。其中Grb2-SH2结构域位于PSpYVNVQN的1.5埃，Grb2-SH2结构域位于Maz*-Py-(AlphaMe)Py-N-NH2伪肽的2埃。两者都与在2.7埃确定的未连接的SH2结构进行了比较，有趣的是，这种结构通过两个对称性相关分子的两个亚区互换形成二聚体。Maz-Py-(AlphaMe)Py-N-NH2伪肽对Grb2-SH2的纳摩尔亲和力与与非保守残基的新的相互作用有关。Grb2-SH2结构域抑制剂的设计可以防止与酪氨酸激酶蛋白或其他适配器如Shc或IRS1的相互作用，从而提供一种阻断RAS信号通路的方法。新合成的伪肽对Grb2-SH2结构域具有纳摩尔亲和力。这样就有可能设计出具有相似亲和力和更简单化学结构的新抑制剂。(C)2002年爱思唯尔科学有限公司。
The activation of growth factor receptors induces phosphorylation of tyrosine residues in its C-terminal part, creating binding sites for SH2 domain-containing proteins. Grb2 is a protein that recruits Sos, the exchange factor for Ras. Recruitment of Sos allows for Ras activation and subsequent signal transmission. This promotes translocation of MAP kinases into the nucleus and activation of early transcription factors. Grb2, a 25 kDa protein, is composed of one SH2 domain surrounded by two SH3 domains. The SH2 domain of Grb2 binds to class II phosphotyrosyl peptides with the consensus sequence pYXNX. Thus, Grb2 is a good example of a bifunctional adaptor protein that brings proteins into close proximity, allowing signal transduction through proteins located in different compartments.To explore the interactions between Grb2 and phosphorylated ligands, we have solved the crystal structure of complexes between the Grb2-SH2 domain and peptides corresponding to Shc-derived sequences. Two structures are described: the Grb2-SH2 domain in complex with PSpYVNVQN at 1.5 Angstrom; and the Grb2-SH2 domain in complex with mAZ*-pY-(alphaMe)pY-N-NH2 pseudo-peptide, at 2 Angstrom. Both are compared to an unliganded SH2 structure determined at 2.7 Angstrom which, interestingly enough, forms a dimer through two swapping subdomains from two symmetry-related molecules. The nanomolar affinity of the mAZ-pY-(alphaMe)pY-N-NH2 pseudo-peptide for Grb2-SH2 is related to new interactions with nonconserved residues.The design of Grb2-SH2 domain inhibitors that prevent interaction with tyrosine kinase proteins or other adaptors like Shc or IRS1 should provide a means to interrupt the Ras signaling pathway. Newly synthesized pseudo-peptides exhibit nanomolar affinities for the Grb2-SH2 domain. It will then be possible to design new inhibitors with similar affinity and simpler chemical structures. (C) 2002 Elsevier Science Limited.