Boute Nicolas, Boubekeur Samira, Lacasa Danièle, Issad Tarik
Department of Cell Biology, Institut Cochin, CNRS-UMR 8104, INSERM U567, Université Paris V, 22 Rue Méchain, 75014 Paris, France.
EMBO Rep. 2003 Mar;4(3):313-9. doi: 10.1038/sj.embor.embor767.
The dynamics of the interaction of the insulin receptor with a substrate-trapping mutant of protein-tyrosine phosphatase 1B (PTP1B) were monitored in living human embryonic kidney cells using bioluminescence resonance energy transfer (BRET). Insulin dose-dependently stimulates this interaction, which could be followed in real time for more than 30 minutes. The effect of insulin on the BRET signal could be detected at early time-points (30 seconds), suggesting that in intact cells the tyrosine-kinase activity of the insulin receptor is tightly controlled by PTP1B. Interestingly, the basal (insulin-independent) interaction of the insulin receptor with PTP1B was much weaker with a soluble form of the tyrosine-phosphatase than with the endoplasmic reticulum (ER)-targeted form. Inhibition of insulin-receptor processing using tunicamycin suggests that the basal interaction occurs during insulin-receptor biosynthesis in the ER. Therefore, localization of PTP1B in this compartment might be important for the regulation of insulin receptors during their biosynthesis.
利用生物发光共振能量转移(BRET)技术,在活的人胚肾细胞中监测了胰岛素受体与蛋白酪氨酸磷酸酶1B(PTP1B)底物捕获突变体之间的相互作用动力学。胰岛素呈剂量依赖性地刺激这种相互作用,这种相互作用可以实时跟踪30多分钟。在早期时间点(30秒)就能检测到胰岛素对BRET信号的影响,这表明在完整细胞中,胰岛素受体的酪氨酸激酶活性受PTP1B的严格控制。有趣的是,与内质网(ER)靶向形式相比,胰岛素受体与酪氨酸磷酸酶的可溶性形式之间的基础(不依赖胰岛素)相互作用要弱得多。用衣霉素抑制胰岛素受体加工表明基础相互作用发生在内质网中胰岛素受体生物合成过程中。因此,PTP1B在该区室中的定位可能对胰岛素受体生物合成过程中的调节很重要。