Elements of the ERAD ubiquitin ligase Doa10 regulating sequential poly-ubiquitylation of its targets.
| Autor: | Mehrtash AB; Department of Molecular, Cellular, & Developmental Biology, Yale University, New Haven, 06520 CT, USA., Hochstrasser M; Department of Molecular, Cellular, & Developmental Biology, Yale University, New Haven, 06520 CT, USA.; Department of Molecular Biophysics & Biochemistry, Yale University, New Haven, CT 06520, USA. |
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| Jazyk: | angličtina |
| Zdroj: | IScience [iScience] 2022 Oct 13; Vol. 25 (11), pp. 105351. Date of Electronic Publication: 2022 Oct 13 (Print Publication: 2022). |
| DOI: | 10.1016/j.isci.2022.105351 |
| Abstrakt: | In ER-associated degradation (ERAD), misfolded ER proteins are degraded by the proteasome after undergoing ubiquitylation. Yeast Doa10 (human MARCHF6/TEB4) is a membrane-embedded E3 ubiquitin ligase that functions with E2s Ubc6 and Ubc7. Ubc6 attaches a single ubiquitin to substrates, which is extended by Ubc7 to form a polyubiquitin chain. We show the conserved C-terminal element (CTE) of Doa10 promotes E3-mediated Ubc6 activity. Doa10 substrates undergoing an alternative ubiquitylation mechanism are still degraded in CTE-mutant cells. Structure prediction by AlphaFold2 suggests the CTE binds near the catalytic RING-CH domain, implying a direct role in substrate ubiquitylation, and we confirm this interaction using intragenic suppression. Truncation analysis defines a minimal E2-binding region of Doa10; structural predictions suggest that Doa10 forms a retrotranslocation channel and that E2s bind within the cofactor-binding region defined here. These results provide mechanistic insight into how Doa10, and potentially other ligases, interact with their cofactors and mediate ERAD. Competing Interests: The authors declare no competing interests. (© 2022 The Author(s).) |
| Databáze: | MEDLINE |
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