NORE1A (RASSF5) is a tumor suppressor of the RASSF family that is often down-regulated in human tumors. NORE1A has multiple roles in controlling cellular homeostasis, one of them being regulating levels of β-catenin ...NORE1A (RASSF5) is a tumor suppressor of the RASSF family that is often down-regulated in human tumors. NORE1A has multiple roles in controlling cellular homeostasis, one of them being regulating levels of β-catenin by binding and modulating the ubiquitin ligase substrate recognition factor β-TrCP. β-catenin is a major executor of the Wnt pathway. The ubiquitin SCF-β-TrCP ligase complex acts on a phospho-degron site in β-catenin that can be phosphorylated by GSK-3β. We now show that in addition to binding β-TrCP, NORE1A also promotes the phosphorylation of the β-catenin phospho-degron by complexing with the kinase GSK-3β. Indeed, NORE1A enhances the formation of a GSK-3β/β-TrCP complex. A structural mutant of NORE1A that retains β-TrCP binding but will no longer interact with GSK-3β inhibits the β-catenin degrading action of NORE1A. The GSK-3β interaction with NORE1A plays an important role in the biology of NORE1A as a GSK-3β inhibitor blocks NORE1A induced senescence. Thus, we identify a new role for the tumor suppressor NORE1A: The regulation of GSK-3β. GSK-3β has many other substrates including multiple transcription factors and co-activators such as p53 and the Hippo component TAZ. The work implies that NORE1A may be able to influence all of them via this new kinase scaffolding interaction.展开更多
目的研究膀胱癌中,RASSF2A、NORE1A基因启动子甲基化状态在肿瘤发生发展中的作用。方法采用甲基化特异性PCR(methylation specific PCR,MSP)技术检测54例膀胱癌组织及其相应癌周正常组织RASSF2A、NORE1A基因启动子甲基化状态。结果(1)RA...目的研究膀胱癌中,RASSF2A、NORE1A基因启动子甲基化状态在肿瘤发生发展中的作用。方法采用甲基化特异性PCR(methylation specific PCR,MSP)技术检测54例膀胱癌组织及其相应癌周正常组织RASSF2A、NORE1A基因启动子甲基化状态。结果(1)RASSF2A检出率仅为2/54,NORE1A仅为0/54;(2)相应癌周正常组织和3例正常膀胱组织均未发现该基因高甲基化改变;(3)甲基化状态与膀胱癌临床病理参数无明显相关性。结论RASSF2A、NORE1A在膀胱肿瘤中的甲基化率较低,并不适合进行临床筛查。展开更多
文摘NORE1A (RASSF5) is a tumor suppressor of the RASSF family that is often down-regulated in human tumors. NORE1A has multiple roles in controlling cellular homeostasis, one of them being regulating levels of β-catenin by binding and modulating the ubiquitin ligase substrate recognition factor β-TrCP. β-catenin is a major executor of the Wnt pathway. The ubiquitin SCF-β-TrCP ligase complex acts on a phospho-degron site in β-catenin that can be phosphorylated by GSK-3β. We now show that in addition to binding β-TrCP, NORE1A also promotes the phosphorylation of the β-catenin phospho-degron by complexing with the kinase GSK-3β. Indeed, NORE1A enhances the formation of a GSK-3β/β-TrCP complex. A structural mutant of NORE1A that retains β-TrCP binding but will no longer interact with GSK-3β inhibits the β-catenin degrading action of NORE1A. The GSK-3β interaction with NORE1A plays an important role in the biology of NORE1A as a GSK-3β inhibitor blocks NORE1A induced senescence. Thus, we identify a new role for the tumor suppressor NORE1A: The regulation of GSK-3β. GSK-3β has many other substrates including multiple transcription factors and co-activators such as p53 and the Hippo component TAZ. The work implies that NORE1A may be able to influence all of them via this new kinase scaffolding interaction.
文摘目的研究膀胱癌中,RASSF2A、NORE1A基因启动子甲基化状态在肿瘤发生发展中的作用。方法采用甲基化特异性PCR(methylation specific PCR,MSP)技术检测54例膀胱癌组织及其相应癌周正常组织RASSF2A、NORE1A基因启动子甲基化状态。结果(1)RASSF2A检出率仅为2/54,NORE1A仅为0/54;(2)相应癌周正常组织和3例正常膀胱组织均未发现该基因高甲基化改变;(3)甲基化状态与膀胱癌临床病理参数无明显相关性。结论RASSF2A、NORE1A在膀胱肿瘤中的甲基化率较低,并不适合进行临床筛查。
