The E3 ubiquitin ligase SCF(Fbxo7) mediates proteasomal degradation of UXT isoform 2 (UXT-V2) to inhibit the NF-κB signaling pathway
| Autor: | Patrícia Maria Siqueira dos Passos, Natália Borges Simaroli, Felipe R. Teixeira, Tycho E. T. Mevissen, Joice S. Oliveira, Marcelo D. Gomes, Heike Laman, Valentine Spagnol, Camila R.S.T.B. de Correia, Suzanne J. Randle, David Komander, Caio Almeida Batista de Oliveira, Ana C. Medeiros |
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| Přispěvatelé: | Laman, Heike [0000-0002-6089-171X], Apollo - University of Cambridge Repository |
| Rok vydání: | 2021 |
| Předmět: |
0301 basic medicine
TRAF2 Proteasome Endopeptidase Complex UXT-V1 UXT-V2 RBX1 Biophysics Cell Cycle Proteins NF-kappa B (NF-κB) Biochemistry Article Enhanceosome 03 medical and health sciences Ubiquitylation (ubiquitination) Ubiquitin Cell Line Tumor Skp1 Humans Protein Isoforms Molecular Biology Gene knockdown SKP Cullin F-Box Protein Ligases 030102 biochemistry & molecular biology biology Chemistry F-Box Proteins NF-kappa B Ubiquitination Cell biology Ubiquitin ligase SCF(Fbxo7) 030104 developmental biology HEK293 Cells E3 ubiquitin ligase Proteolysis biology.protein Signal transduction TRANSDUÇÃO DE SINAL CELULAR Molecular Chaperones Signal Transduction |
| Zdroj: | Repositório Institucional da USP (Biblioteca Digital da Produção Intelectual) Universidade de São Paulo (USP) instacron:USP Biochimica et Biophysica Acta. General Subjects |
| Popis: | Background Ubiquitously eXpressed Transcript isoform 2 (UXT—V2) is a prefoldin-like protein involved in NF-κB signaling, apoptosis, and the androgen and estrogen response. UXT-V2 is a cofactor in the NF-κB transcriptional enhanceosome, and its knockdown inhibits TNF-α -induced NF-κB activation. Fbxo7 is an F-box protein that interacts with SKP1, Cullin1 and RBX1 proteins to form an SCF(Fbxo7) E3 ubiquitin ligase complex. Fbxo7 negatively regulates NF-κB signaling through TRAF2 and cIAP1 ubiquitination. Methods We combine co-immunoprecipitation, ubiquitination in vitro and in vivo, cycloheximide chase assay, ubiquitin chain restriction analysis and microscopy to investigate interaction between Fbxo7 and overexpressed UXT-V2-HA. Results The Ubl domain of Fbxo7 contributes to interaction with UXT—V2. This substrate is polyubiquitinated by SCF(Fbxo7) with K48 and K63 ubiquitin chain linkages in vitro and in vivo. This post-translational modification decreases UXT-V2 stability and promotes its proteasomal degradation. We further show that UXT—V1, an alternatively spliced isoform of UXT, containing 12 additional amino acids at the N-terminus as compared to UXT—V2, also interacts with and is ubiquitinated by Fbxo7. Moreover, FBXO7 knockdown promotes UXT-V2 accumulation, and the overexpression of Fbxo7-ΔF-box protects UXT-V2 from proteasomal degradation and enhances the responsiveness of NF-κB reporter. We find that UXT-V2 colocalizes with Fbxo7 in the cell nucleus. Conclusions Together, our study reveals that SCF(Fbxo7) mediates the proteasomal degradation of UXT-V2 causing the inhibition of the NF-κB signaling pathway. General significance Discovering new substrates of E3 ubiquitin-ligase SCF(Fbxo7) contributes to understand its function in different diseases such as cancer and Parkinson. Highlights • UXT-V2 is a canonical substrate of SCF(Fbxo7) E3 ubiquitin ligase. • Fbxo7 interacts with both UXT-V1 and UXT—V2. • UXT-V2 recruits Fbxo7 to the cell nuclei. • Fbxo7 inhibit NF-kB pathway through degradation of UXT-V2. |
| Databáze: | OpenAIRE |
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