Landázuri Manuel O, Vara-Vega Alicia, Vitón Mariano, Cuevas Yolanda, del Peso Luis
Departamento de Bioquímica, Instituto de Investigaciones Biomédicas Alberto Sols, Consejo Superior de Investigaciones Científicas-Universidad Autónoma de Madrid, Arturo Duperier 4, 28029 Madrid, Spain.
Biochem Biophys Res Commun. 2006 Dec 15;351(2):313-20. doi: 10.1016/j.bbrc.2006.09.170. Epub 2006 Oct 16.
Hypoxia inducible transcription factors (HIF) are mainly regulated by a group of proline hydroxylases (EGLNs) that, in the presence of oxygen, target HIF for degradation. HIFalpha contains two independent oxygen degradation domains (N-ODD and C-ODD) that are substrates for these enzymes. In this work, we employed the yeast two-hybrid assay to study the sequence determinants required for the binding of EGLN1 and 3 to HIF1alpha in a cellular context. Our results demonstrate that, while EGLN1 is able to recognize both ODDs within full length HIF1alpha protein, EGLN3 only binds to CODD. The analysis of the residue substitutions within CODD uncovered novel critical determinants for EGLN1 and 3 binding. In addition, our results show that both enzymes have a very similar, albeit not identical, residue preference at specific positions in their substrate sequences.
缺氧诱导转录因子（HIF）主要受一组脯氨酰羟化酶（EGLNs）调控，在有氧条件下，EGLNs会将HIF作为降解靶点。HIFα包含两个独立的氧降解结构域（N-ODD和C-ODD），它们是这些酶的底物。在本研究中，我们利用酵母双杂交试验，在细胞环境中研究EGLN1和3与HIF1α结合所需的序列决定因素。我们的结果表明，虽然EGLN1能够识别全长HIF1α蛋白中的两个ODD，但EGLN3仅与C-ODD结合。对C-ODD内残基取代的分析揭示了EGLN1和3结合的新关键决定因素。此外，我们的结果表明，这两种酶在其底物序列的特定位置具有非常相似（尽管不完全相同）的残基偏好。
