Structural basis for PAS domain heterodimerization in the basic helix-loop-helix-PAS transcription factor hypoxia-inducible factor
Structural basis for PAS domain heterodimerization in the basic helix-loop-helix-PAS transcription factor hypoxia-inducible factor
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DOI：
10.1073/pnas.2533374100
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发表时间：
2003-12-23
影响因子：
11.1
通讯作者：
Gardner, KH
中科院分区：
文献类型：
--
作者：
Erbel, PJA;Card, PB;Gardner, KH
对氧气可用性的生物反应在发育、生理稳态和许多疾病过程中发挥着重要作用。在哺乳动物细胞中，这种适应部分是由以缺氧诱导因子（HIF）为中心的保守途径介导的。 HIF 是一种异二聚体蛋白复合物，由转录激活因子的基本螺旋-环-螺旋 Per-ARNT-Sim (PAS)（ARNT，芳基烃受体核转位子）结构域家族的两个成员 HIFα 和 ARNT 组成。尽管这种复合物涉及由两种蛋白质中的基本螺旋-环-螺旋和PAS结构域介导的蛋白质-蛋白质相互作用，但PAS结构域所起的作用却知之甚少。为了解决这个问题，我们通过核磁共振波谱研究了人 HIF-2α C 端 PAS 结构域的结构和相互作用。我们证明 HIF-2α PAS-β 在体外结合类似的 ARNT 结构域，表明参与这种相互作用的残基位于 HIF-2α 中央 β 片层的溶剂暴露侧。该表面的突变残基不仅会破坏体外分离的 PAS 结构域之间的相互作用，还会干扰全长 HIF 响应活细胞缺氧的能力。将我们的发现扩展到其他 PAS 域，我们发现这种 β-折叠界面广泛用于分子内和分子间相互作用，这表明许多类型的包含 PAS 的信号蛋白的特异性和调节基础。
Biological responses to oxygen availability play important roles in development, physiological homeostasis, and many disease processes. In mammalian cells, this adaptation is mediated in part by a conserved pathway centered on the hypoxia-inducible factor (HIF). HIF is a heterodimeric protein complex composed of two members of the basic helix-loop-helix Per-ARNT-Sim (PAS) (ARNT, aryl hydrocarbon receptor nuclear translocator) domain family of transcriptional activators, HIFalpha and ARNT. Although this complex involves protein-protein interactions mediated by basic helix-loop-helix and PAS domains in both proteins, the role played by the PAS domains is poorly understood. To address this issue, we have studied the structure and interactions of the C-terminal PAS domain of human HIF-2alpha by NMR spectroscopy. We demonstrate that HIF-2alpha PAS-beta binds the analogous ARNT domain in vitro, showing that residues involved in this interaction are located on the solvent-exposed side of the HIF-2alpha central beta-sheet. Mutating residues at this surface not only disrupts the interaction between isolated PAS domains in vitro but also interferes with the ability of full-length HIF to respond to hypoxia in living cells. Extending our findings to other PAS domains, we find that this beta-sheet interface is widely used for both intra- and intermolecular interactions, suggesting a basis of specificity and regulation of many types of PAS-containing signaling proteins.