Friend spleen focus-forming virus glycoprotein gp55 interacts with the erythropoietin receptor in the endoplasmic reticulum and affects receptor metabolism.
Friend spleen focus-forming virus glycoprotein gp55 interacts with the erythropoietin receptor in the endoplasmic reticulum and affects receptor metabolism.
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Friend脾病灶形成病毒糖蛋白gp55与内质网中的促红细胞生成素受体相互作用并影响受体代谢。
DOI：
10.1073/pnas.87.11.4139
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发表时间：
1990
影响因子：
11.1
通讯作者：
Lodish,HF
中科院分区：
文献类型：
--
作者：
Yoshimura,A;D'Andrea,AD;Lodish,HF
Friend脾病灶形成病毒包膜糖蛋白gp55与小鼠促红细胞生成素受体（EPO- r）结合，并在EPO缺失时触发生长激活。稳定转染EPO- r cDNA的白细胞介素3依赖性淋巴细胞系在EPO或白细胞介素3存在下生长。在这些细胞中，EPO-R以62 kda的非糖基化形式和64 kda的主要形式合成，携带一种高甘露糖n连接的低聚糖。64-kDa形式的一小部分被加工成66-kDa的复杂型糖。很少的EPO-R在细胞表面表达，所有三种形式的EPO-R都被迅速降解。同时转染EPO- r和gp55 cdna的细胞在缺乏EPO的情况下生长。大多数与gp55相关的EPO-R是内糖苷酶h敏感的，这表明这些蛋白之间的相互作用发生在内质网中。此外，内糖苷酶h敏感的EPO-R比没有gp55时更稳定，这表明gp55与EPO-R的相互作用使其留在粗内质网内。可能这个隔室内的gp55 EPO-R复合物向细胞发送促进生长的信号。
The Friend spleen focus-forming virus envelope glycoprotein, gp55, binds to the murine erythropoietin receptor (EPO-R) and triggers growth activation in the absence of EPO. Interleukin 3-dependent lymphoid cell lines that have been stably transfected with the EPO-R cDNA grow in the presence of EPO or interleukin 3. In these cells, the EPO-R is synthesized as a minor 62-kDa unglycosylated form and a major 64-kDa form carrying one high-mannose N-linked oligosaccharide. A fraction of the 64-kDa form is processed to a 66-kDa species with complex-type sugars. Very little of the EPO-R is expressed on the cell surface and all three forms of EPO-R are degraded rapidly. Cells transfected with both EPO-R and gp55 cDNAs grow in the absence of EPO. Most of the EPO-R associated with gp55 is endoglycosidase H-sensitive, suggesting that the interactions between these proteins occur in the endoplasmic reticulum. Furthermore, the endoglycosidase H-sensitive EPO-R is more stable than in the absence of gp55, a result suggesting that interaction of gp55 with the EPO-R causes it to remain within the rough endoplasmic reticulum. It is possible that gp55 EPO-R complexes within this compartment send a growth-promoting signal to the cell.