Genetic aberrations of the UBE3A gene encoding the E3 ubiquitin ligase E6AP underlie the development of Angelman syndrome (AS). Approximately 10% of AS individuals harbor UBE3A genes with point mutations, frequently resulting in the expression of full-length E6AP variants with defective E3 activity. Since E6AP exists in two states, an inactive and an active one, we hypothesized that distinct small molecules can stabilize the active state and that such molecules may rescue the E3 activity of AS-derived E6AP variants. Therefore, we established an assay that allows identifying modulators of E6AP in a high-throughput format. We identified several compounds that not only stimulate wild-type E6AP but also rescue the E3 activity of certain E6AP variants. Moreover, by chemical cross-linking coupled to mass spectrometry we provide evidence that the compounds stabilize an active conformation of E6AP. Thus, these compounds represent potential lead structures for the design of drugs for AS treatment.

编码E3泛素连接酶E6AP的UBE3A基因的遗传畸变是Angelman综合征（AS）发展的基础。大约10％的AS个体拥有UBE3A带有点突变的基因，经常导致具有E3活性缺陷的全长E6AP变体的表达。由于E6AP存在两种状态，一种为非活性状态，一种为活性状态，因此我们假设不同的小分子可以稳定活性状态，并且这种分子可以拯救AS衍生的E6AP变体的E3活性。因此，我们建立了一种测定方法，该方法可以鉴定高通量格式的E6AP调节剂。我们鉴定了几种化合物，它们不仅可以刺激野生型E6AP，而且可以拯救某些E6AP变体的E3活性。此外，通过化学交联与质谱联用，我们提供了证明该化合物稳定E6AP活性构象的证据。因此，这些化合物代表了用于AS治疗药物设计的潜在先导结构。