Download MendeleyDistinct Perception Mechanisms of BACH1 Quaternary Structure Degrons by Two F-box Proteins under Oxidative Stress.
Cao, S., Shi, H., Garcia, S.F., Kito, Y., Shi, H., Goldberg, H.V., Ponce, J., Ueberheide, B., Lignitto, L., Pagano, M., Zheng, N.(2024) bioRxiv
- PubMed: 38895309
- DOI: https://doi.org/10.1101/2024.06.03.594717
- Primary Citation of Related Structures:
8UA3, 8UA6, 8UAH, 8UBT, 8UBU, 8UBV - PubMed Abstract:
The transcription factor BACH1 regulates heme homeostasis and oxidative stress responses and promotes cancer metastasis upon aberrant accumulation. Its stability is controlled by two F-box protein ubiquitin ligases, FBXO22 and FBXL17. Here we show that the homodimeric BTB domain of BACH1 functions as a previously undescribed quaternary structure degron, which is deciphered by the two F-box proteins via distinct mechanisms. After BACH1 is released from chromatin by heme, FBXO22 asymmetrically recognizes a cross-protomer interface of the intact BACH1 BTB dimer, which is otherwise masked by the co-repressor NCOR1. If the BACH1 BTB dimer escapes the surveillance by FBXO22 due to oxidative modifications, its quaternary structure integrity is probed by a pair of FBXL17, which simultaneously engage and remodel the two BTB protomers into E3-bound monomers for ubiquitination. By unveiling the multifaceted regulatory mechanisms of BACH1 stability, our studies highlight the abilities of ubiquitin ligases to decode high-order protein assemblies and reveal therapeutic opportunities to block cancer invasion via compound-induced BACH1 destabilization.
Organizational Affiliation:
Department of Pharmacology, Box 357280, University of Washington, Seattle, WA, USA.
