Active and inactive orientations of the transmembrane and cytosolic domains of the erythropoietin receptor dimer.
Active and inactive orientations of the transmembrane and cytosolic domains of the erythropoietin receptor dimer.
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DOI：
10.1016/s1097-2765(03)00389-7
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发表时间：
2003-11
期刊：
影响因子：
16
通讯作者：
Nadine Seubert;Yohan Royer;J. Staerk;K. Kubatzky;V. Moucadel;Shyam S. Krishnakumar;Steven O. Smith
中科院分区：
文献类型：
--
作者：
Nadine Seubert;Yohan Royer;J. Staerk;K. Kubatzky;V. Moucadel;Shyam S. Krishnakumar;Steven O. Smith
促红细胞生成素与促红细胞生成素受体（EpoR）胞外结构域的结合将受体二聚体的跨膜（TM）和胞质区域定向成未知的活化构象。通过用二聚体卷曲螺旋替换EpoR胞外结构域，我们设计了TM EpoR融合蛋白，其中螺旋TM结构域被限制为七种可能的相对取向。我们确定了一个二聚体TM构象，赋予完全活性的受体的胞质结构域和信号通过JAK2，STAT蛋白，和MAP激酶，一个部分活跃的方向，优先激活MAP激酶，和一个构象对应于无活性的受体。通过计算搜索低能量TM二聚体结构，独立地确定了活性和非活性构象。我们提出了一个特定的EpoR激活接口，并建议其用于结构和信号研究。
Binding of erythropoietin to the erythropoietin receptor (EpoR) extracellular domain orients the transmembrane (TM) and cytosolic regions of the receptor dimer into an unknown activated conformation. By replacing the EpoR extracellular domain with a dimeric coiled coil, we engineered TM EpoR fusion proteins where the helical TM domains were constrained into seven possible relative orientations. We identify one dimeric TM conformation that imparts full activity to the cytosolic domain of the receptor and signals via JAK2, STAT proteins, and MAP kinase, one partially active orientation that preferentially activates MAP kinase, and one conformation corresponding to the inactive receptor. The active and inactive conformations were independently identified by computational searches for low-energy TM dimeric structures. We propose a specific EpoR-activated interface and suggest its use for structural and signaling studies.