Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, MA 02115, USA; Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA.
Department of Cellular and Molecular Medicine, Institute of Genomic Medicine, University of California, San Diego, La Jolla, CA 92093, USA.
Cell Chem Biol. 2018 Apr 19;25(4):460-470.e6. doi: 10.1016/j.chembiol.2018.01.013. Epub 2018 Feb 22.
The SRPK family of kinases regulates pre-mRNA splicing by phosphorylating serine/arginine (SR)-rich splicing factors, signals splicing control in response to extracellular stimuli, and contributes to tumorigenesis, suggesting that these splicing kinases are potential therapeutic targets. Here, we report the development of the first irreversible SRPK inhibitor, SRPKIN-1, which is also the first kinase inhibitor that forms a covalent bond with a tyrosine phenol group in the ATP-binding pocket. Kinome-wide profiling demonstrates its selectivity for SRPK1/2, and SRPKIN-1 attenuates SR protein phosphorylation at submicromolar concentrations. Vascular endothelial growth factor (VEGF) is a known target for SRPK-regulated splicing and, relative to the first-generation SRPK inhibitor SRPIN340 or small interfering RNA-mediated SRPK knockdown, SRPKIN-1 is more potent in converting the pro-angiogenic VEGF-A165a to the anti-angiogenic VEGF-A165b isoform and in blocking laser-induced neovascularization in a murine retinal model. These findings encourage further development of SRPK inhibitors for treatment of age-related macular degeneration.
SRPK 家族激酶通过磷酸化丝氨酸/精氨酸 (SR)-富含拼接因子来调节前体 mRNA 拼接，响应细胞外刺激信号来控制拼接，并有助于肿瘤发生，这表明这些拼接激酶是潜在的治疗靶点。在这里，我们报告了第一种不可逆的 SRPK 抑制剂 SRPKIN-1 的开发，它也是第一种与 ATP 结合口袋中酪氨酸酚基团形成共价键的激酶抑制剂。全激酶组谱分析表明其对 SRPK1/2 的选择性，并且 SRPKIN-1 以亚微摩尔浓度抑制 SR 蛋白磷酸化。血管内皮生长因子 (VEGF) 是已知的受 SRPK 调节拼接的靶点，与第一代 SRPK 抑制剂 SRPIN340 或小干扰 RNA 介导的 SRPK 敲低相比，SRPKIN-1 更有效地将促血管生成的 VEGF-A165a 转化为抗血管生成的 VEGF-A165b 异构体，并在小鼠视网膜模型中阻断激光诱导的新生血管形成。这些发现鼓励进一步开发 SRPK 抑制剂用于治疗年龄相关性黄斑变性。
