Department of Pathology, University of New Mexico, Albuquerque, New Mexico 87131; University of New Mexico (UNM) Center for Molecular Discovery, University of New Mexico, Albuquerque, New Mexico 87131.
Department of Pharmaceutical Sciences, University of New Mexico, Albuquerque, New Mexico 87131.
J Biol Chem. 2013 Mar 22;288(12):8531-8543. doi: 10.1074/jbc.M112.435941. Epub 2013 Feb 4.
Cdc42 plays important roles in cytoskeleton organization, cell cycle progression, signal transduction, and vesicle trafficking. Overactive Cdc42 has been implicated in the pathology of cancers, immune diseases, and neuronal disorders. Therefore, Cdc42 inhibitors would be useful in probing molecular pathways and could have therapeutic potential. Previous inhibitors have lacked selectivity and trended toward toxicity. We report here the characterization of a Cdc42-selective guanine nucleotide binding lead inhibitor that was identified by high throughput screening. A second active analog was identified via structure-activity relationship studies. The compounds demonstrated excellent selectivity with no inhibition toward Rho and Rac in the same GTPase family. Biochemical characterization showed that the compounds act as noncompetitive allosteric inhibitors. When tested in cellular assays, the lead compound inhibited Cdc42-related filopodia formation and cell migration. The lead compound was also used to clarify the involvement of Cdc42 in the Sin Nombre virus internalization and the signaling pathway of integrin VLA-4. Together, these data present the characterization of a novel Cdc42-selective allosteric inhibitor and a related analog, the use of which will facilitate drug development targeting Cdc42-related diseases and molecular pathway studies that involve GTPases.
Cdc42 在细胞骨架组织、细胞周期进程、信号转导和囊泡运输中发挥重要作用。过度活跃的 Cdc42 与癌症、免疫疾病和神经元紊乱的病理学有关。因此，Cdc42 抑制剂在探测分子途径方面将非常有用，并且可能具有治疗潜力。以前的抑制剂缺乏选择性，并且趋于毒性。我们在这里报告了一种通过高通量筛选鉴定的 Cdc42 选择性鸟嘌呤核苷酸结合的先导抑制剂的特性。通过结构-活性关系研究鉴定了第二个活性类似物。这些化合物在同一 GTPase 家族中对 Rho 和 Rac 没有抑制作用，表现出极好的选择性。生化特性表明，这些化合物作为非竞争性变构抑制剂起作用。在细胞测定中测试时，先导化合物抑制了与 Cdc42 相关的丝状伪足形成和细胞迁移。该先导化合物还用于阐明 Cdc42 在 Sin Nombre 病毒内化和整合素 VLA-4 信号通路中的作用。总之，这些数据呈现了一种新型的 Cdc42 选择性变构抑制剂及其相关类似物的特性，其使用将有助于针对 Cdc42 相关疾病和涉及 GTPases 的分子途径研究的药物开发。
