The APC/C E3 Ligase Complex Activator FZR1 Restricts BRAF Oncogenic Function
| Autor: | Kelsey Berry, Jacqueline Fung, Wenyi Wei, C Ng, Pengda Liu, Ming Chen, Xiangpeng Dai, Pier Paolo Pandolfi, Min Sup Song, Jesse Katon, Marc W. Kirschner, Hiroyuki Inuzuka, Jing Liu, Lian Xue, Juxiang Cao, Rutao Cui, Roderick T. Bronson, Jinfang Zhang, Ying Lu, Lixin Wan, Su Jung Song, Qing Yin |
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| Jazyk: | angličtina |
| Rok vydání: | 2017 |
| Předmět: |
0301 basic medicine
MAPK/ERK pathway Proto-Oncogene Proteins B-raf Proteasome Endopeptidase Complex endocrine system diseases Carcinogenesis Ubiquitin-Protein Ligases Adenomatous Polyposis Coli Protein Article Cdh1 Proteins Mice 03 medical and health sciences Cell Line Tumor Animals PTEN Humans Cyclin D1 Phosphorylation Kinase activity Protein Kinase Inhibitors Protein kinase B neoplasms Melanoma Cellular Senescence Cell Proliferation biology Kinase Tumor Suppressor Proteins Ubiquitin-Protein Ligase Complexes Xenograft Model Antitumor Assays digestive system diseases Ubiquitin ligase enzymes and coenzymes (carbohydrates) 030104 developmental biology Oncology Multiprotein Complexes Proteolysis biology.protein Cancer research Melanocytes Signal transduction Anaphase Dimerization HeLa Cells Signal Transduction |
| Popis: | BRAF drives tumorigenesis by coordinating the activation of the RAS/RAF/MEK/ERK oncogenic signaling cascade. However, upstream pathways governing BRAF kinase activity and protein stability remain undefined. Here, we report that in primary cells with active APCFZR1, APCFZR1 earmarks BRAF for ubiquitination-mediated proteolysis, whereas in cancer cells with APC-free FZR1, FZR1 suppresses BRAF through disrupting BRAF dimerization. Moreover, we identified FZR1 as a direct target of ERK and CYCLIN D1/CDK4 kinases. Phosphorylation of FZR1 inhibits APCFZR1, leading to elevation of a cohort of oncogenic APCFZR1 substrates to facilitate melanomagenesis. Importantly, CDK4 and/or BRAF/MEK inhibitors restore APCFZR1 E3 ligase activity, which might be critical for their clinical effects. Furthermore, FZR1 depletion cooperates with AKT hyperactivation to transform primary melanocytes, whereas genetic ablation of Fzr1 synergizes with Pten loss, leading to aberrant coactivation of BRAF/ERK and AKT signaling in mice. Our findings therefore reveal a reciprocal suppression mechanism between FZR1 and BRAF in controlling tumorigenesis.Significance: FZR1 inhibits BRAF oncogenic functions via both APC-dependent proteolysis and APC-independent disruption of BRAF dimers, whereas hyperactivated ERK and CDK4 reciprocally suppress APCFZR1 E3 ligase activity. Aberrancies in this newly defined signaling network might account for BRAF hyperactivation in human cancers, suggesting that targeting CYCLIN D1/CDK4, alone or in combination with BRAF/MEK inhibition, can be an effective anti-melanoma therapy. Cancer Discov; 7(4); 424–41. ©2017 AACR.See related commentary by Zhang and Bollag, p. 356.This article is highlighted in the In This Issue feature, p. 339 |
| Databáze: | OpenAIRE |
| Externí odkaz: |
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