Scholarlink

<p>Identifying effective therapies targeting multi-protein complexes that lack catalytic sites or cofactor pockets remains a long-standing challenge. The proto-oncogene, ubiquitin E3 ligase SCF<sup>Skp2</sup>, is one such target. SCF<sup>Skp2</sup> promotes the proteasomal degradation of the cyclin-dependent kinase inhibitor p27, which controls cell cycle progression. Targeted knockout of <i>Rb1/Trp53</i> causes metastatic prostate cancer in mice; additional knockout of Skp2 completely blocks tumorigenesis. We compared gene-edited mice that carried two different single amino acid changes in the SCF<sup>Skp2</sup> complex, structurally predicted to inhibit the degradation of p27. Mutation of the SCF<sup>Skp2</sup> accessory protein <i>Cks1</i> (Cks1<sup>N45R</sup>) completely blocked <i>Rb1/Trp53</i>-driven prostate tumorigenesis, phenocopying <i>Skp2</i> knockout, whereas a mutation directly stabilizing p27 (p27<sup>T187A</sup>) did not. This was consistent with structural models that predicted the binding of both p27 and p27<sup>T187A</sup> to the SCF<sup>Skp2</sup>/Cks1/Cdk2/CyclinA/p27 complex, and their subsequent ubiquitination and degradation, albeit at different rates. Two binding modes, which differ in their dependence on phosphorylated T187, are predicted by the model. Studies confirmed the role of p27 in mediating tumorigenesis in <i>Rb1/Trp53</i> mutant tumors and revealed a mutually destabilizing Skp2 and p27 feedback loop. The integration of gene editing, drug-surrogate mutations, and mouse tumor models offers a blueprint for studying SCF<sup>Skp2</sup> and other multi-subunit biomedical targets.</p><p></p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Distinct outcomes from targeted perturbations of the multi-subunit SCFSkp2 E3 ubiquitin ligase in blocking Trp53/Rb1-null prostate tumorigenesis

  • 期刊论文

  • 出版模式：

    开放获取

  • 发表日期：

    2025年2月22日

查看全文
  • Yingjiao Xue,
  • Liang Zhu,
  • Saumen Karan,
  • Joseph D. Locker,
  • Craig Branch,
  • Jinghang Zhang,
  • Bang Hoang,
  • Juan Pablo Maianti,
  • Hongling Zhao,
  • Edward L. Schwartz

摘要

Identifying effective therapies targeting multi-protein complexes that lack catalytic sites or cofactor pockets remains a long-standing challenge. The proto-oncogene, ubiquitin E3 ligase SCFSkp2, is one such target. SCFSkp2 promotes the proteasomal degradation of the cyclin-dependent kinase inhibitor p27, which controls cell cycle progression. Targeted knockout of Rb1/Trp53 causes metastatic prostate cancer in mice; additional knockout of Skp2 completely blocks tumorigenesis. We compared gene-edited mice that carried two different single amino acid changes in the SCFSkp2 complex, structurally predicted to inhibit the degradation of p27. Mutation of the SCFSkp2 accessory protein Cks1 (Cks1N45R) completely blocked Rb1/Trp53-driven prostate tumorigenesis, phenocopying Skp2 knockout, whereas a mutation directly stabilizing p27 (p27T187A) did not. This was consistent with structural models that predicted the binding of both p27 and p27T187A to the SCFSkp2/Cks1/Cdk2/CyclinA/p27 complex, and their subsequent ubiquitination and degradation, albeit at different rates. Two binding modes, which differ in their dependence on phosphorylated T187, are predicted by the model. Studies confirmed the role of p27 in mediating tumorigenesis in Rb1/Trp53 mutant tumors and revealed a mutually destabilizing Skp2 and p27 feedback loop. The integration of gene editing, drug-surrogate mutations, and mouse tumor models offers a blueprint for studying SCFSkp2 and other multi-subunit biomedical targets.