RNF8 E3 Ubiquitin Ligase Stimulates Ubc13 E2 Conjugating Activity That Is Essential for DNA Double Strand Break Signaling and BRCA1 Tumor Suppressor Recruitment [electronic resource]

• Ngôn ngữ: eng
• Ký hiệu phân loại: 005.496 Computer programming, programs, data
• Thông tin xuất bản: Washington, D.C. : Oak Ridge, Tenn. : United States. Dept. of Energy. Office of Science ; Distributed by the Office of Scientific and Technical Information, U.S. Dept. of Energy, 2016
• Mô tả vật lý: Size: p. 9396-9410 : , digital, PDF file.
• Bộ sưu tập: Metadata
• ID: 260946
• Chủ đề: 1. 53bp1; 2. 59 basic biological sciences; 3. 60 applied life sciences; 4. Brca1; 5. Cell biology; 6. Dna damage response; 7. E3 ubiquitin-protein ligase rnf8; 8. Et al; 9. Ubiquitylation (ubiquitination); 10. X-ray crystallography; 11. X-ray scattering

Tóm tắt

DNA double strand break (DSB) responses depend on the sequential actions of the E3 ubiquitin ligases RNF8 and RNF168 plus E2 ubiquitin-conjugating enzyme Ubc13 to specifically generate histone Lys-63-linked ubiquitin chains in DSB signaling. In this paper, we defined the activated RNF8-Ubc13~ubiquitin complex by x-ray crystallography and its functional solution conformations by x-ray scattering, as tested by separation-of-function mutations imaged in cells by immunofluorescence. The collective results show that the RING E3 RNF8 targets E2 Ubc13 to DSB sites and plays a critical role in damage signaling by stimulating polyubiquitination through modulating conformations of ubiquitin covalently linked to the Ubc13 active site. Structure-guided separation-of-function mutations show that the RNF8 E2 stimulating activity is essential for DSB signaling in mammalian cells and is necessary for downstream recruitment of 53BP1 and BRCA1. Chromatin-targeted RNF168 rescues 53BP1 recruitment involved in non-homologous end joining but not BRCA1 recruitment for homologous recombination. Finally, these findings suggest an allosteric approach to targeting the ubiquitin-docking cleft at the E2-E3 interface for possible interventions in cancer and chronic inflammation, and moreover, they establish an independent RNF8 role in BRCA1 recruitment.