The yeast ERAD-C ubiquitin ligase Doa10 recognizes an intramembrane degron

Habeck, Gregor; Ebner, Felix A.; Shimada-Kreft, Hiroko; Kreft, Stefan G.

doi:10.1083/jcb.201408088

Cited by 81 publications

(86 citation statements)

References 60 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, Ubc6 appears to be highly promiscuous in target site selection and therefore we observe differences in Ub conjugation kinetics at later time points. This indicates distinct accessibility of individual Ub acceptor sites or differences in the stability of the oxyester and isopeptide bonds in the assay ( Figure S6) (Habeck et al, 2015). Turnover of Sbh2 under these conditions strongly depends on Doa10 and Ubc7 activities, whereas the disruption of UBC6 only moderately affects proteolysis (Figures 6B and S7A; (Habeck et al, 2015)).…”

Section: K48-pub Chain Formationmentioning

confidence: 97%

“…This indicates distinct accessibility of individual Ub acceptor sites or differences in the stability of the oxyester and isopeptide bonds in the assay ( Figure S6) (Habeck et al, 2015). Turnover of Sbh2 under these conditions strongly depends on Doa10 and Ubc7 activities, whereas the disruption of UBC6 only moderately affects proteolysis (Figures 6B and S7A; (Habeck et al, 2015)). This implies that a large proportion of Sbh2 is degraded independently of Ubc6.…”

Section: K48-pub Chain Formationmentioning

confidence: 97%

See 1 more Smart Citation

Sequential Poly-ubiquitylation by Specialized Conjugating Enzymes Expands the Versatility of a Quality Control Ubiquitin Ligase

et al. 2016

View full text Add to dashboard Cite

SummaryThe Doa10 quality control ubiquitin (Ub) ligase labels proteins with uniform lysine 48-linked poly-Ub (K48-pUB) chains for proteasomal degradation. Processing of Doa10 substrates requires the activity of two Ub conjugating enzymes. Here we show that the non-canonical conjugating enzyme Ubc6 attaches single Ub molecules not only to lysines but also to hydroxylated amino acids. These Ub moieties serve as primers for subsequent poly-ubiquitylation by Ubc7. We propose that the evolutionary conserved propensity of Ubc6 to mount Ub on diverse amino acids augments the ubiquitylation sites within a substrate and thereby increases the target range of Doa10. Our work provides new insights on how the consecutive activity of two specialized conjugating enzymes facilitates the attachment of poly-Ub to very heterogeneous client molecules. Such stepwise ubiquitylation reactions most likely represent a more general cellular phenomenon that extends the versatility, yet sustains the specificity of the Ub conjugation system.

show abstract

Section: K48-pub Chain Formationmentioning

confidence: 97%

Section: K48-pub Chain Formationmentioning

confidence: 97%

Sequential Poly-ubiquitylation by Specialized Conjugating Enzymes Expands the Versatility of a Quality Control Ubiquitin Ligase

et al. 2016

View full text Add to dashboard Cite

show abstract

“…Doa10 is localized in the ER and inner nuclear membranes (6) and targets misfolded cytosolic/nucle-oplasmic domains of soluble and membrane-embedded proteins, termed ERAD-C substrates (7). Recently, Doa10 was also found to target an ERAD-M substrate (8).…”

mentioning

confidence: 99%

A Conserved C-terminal Element in the Yeast Doa10 and Human MARCH6 Ubiquitin Ligases Required for Selective Substrate Degradation

Zattas

Berk

Kreft

et al. 2016

Journal of Biological Chemistry

Self Cite

View full text Add to dashboard Cite

Specific proteins are modified by ubiquitin at the endoplasmic reticulum (ER) and are degraded by the proteasome, a process referred to as ER-associated protein degradation. In Saccharomyces cerevisiae, two principal ER-associated protein degradation ubiquitin ligases (E3s) reside in the ER membrane, Doa10 and Hrd1. The membrane-embedded Doa10 functions in the degradation of substrates in the ER membrane, nuclear envelope, cytoplasm, and nucleoplasm. How most E3 ligases, including Doa10, recognize their protein substrates remains poorly understood. Here we describe a previously unappreciated but highly conserved C-terminal element (CTE) in Doa10; this cytosolically disposed 16-residue motif follows the final transmembrane helix. A conserved CTE asparagine residue is required for ubiquitylation and degradation of a subset of Doa10 substrates. Such selectivity suggests that the Doa10 CTE is involved in substrate discrimination and not general ligase function. Functional conservation of the CTE was investigated in the human ortholog of Doa10, MARCH6 (TEB4), by analyzing MARCH6 autoregulation of its own degradation. Mutation of the conserved Asn residue (N890A) in the MARCH6 CTE stabilized the normally short lived enzyme to the same degree as a catalytically inactivating mutation (C9A). We also report the localization of endogenous MARCH6 to the ER using epitope tagging of the genomic MARCH6 locus by clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9-mediated genome editing. These localization and CTE analyses support the inference that MARCH6 and Doa10 are functionally similar. Moreover, our results with the yeast enzyme suggest that the CTE is involved in the recognition and/or ubiquitylation of specific protein substrates.Selective protein degradation in eukaryotic cells is largely carried out by the ubiquitin-proteasome system. Proteins identified for degradation by the ubiquitin-proteasome system are covalently modified with ubiquitin, a highly conserved 76-residue protein (1, 2). In most cases, ubiquitin is conjugated to the target protein via an amide linkage between its C-terminal glycine and ⑀-amino groups on substrate lysine residues. Ubiquitylation requires an enzyme cascade beginning with an E1 ubiquitin-activating enzyme, which adenylates the ubiquitin C-terminal carboxyl group and subsequently forms a high energy thioester bond with it. Ubiquitin is then transferred from the E1 active site cysteine to a cysteine in an E2 ubiquitinconjugating enzyme. Finally, an E3 ubiquitin ligase mediates ubiquitin transfer from the E2 to the target protein. E3s come in several mechanistically distinct classes, but the most abundant are the RING E3s. The RING domain is characterized by a set of Cys and His residues that coordinate a pair of zinc ions; the RING directly contacts the E2-ubiquitin thioester-linked complex and promotes ubiquitin transfer to a substrate (3). Polyubiquitin chains are formed when the C terminus of one donor ubiquitin is conjugated to one of seven lysine residues, or the ...

show abstract

“…Doa10 typically targets proteins with cytosolic degrons (ERAD-C substrates), whereas Hrd1 targets proteins with degrons in the ER lumen (ERAD-L substrates) or within membrane-spanning segments (ERAD-M substrates) (33)(34)(35)(36)(37)(38). However, Doa10 has also recently been shown to recognize an intramembrane (ERAD-M) degron (39). Additionally, Hrd1 may target for degradation proteins that persistently or aberrantly engage the ER-localized translocon (ERAD-T substrates) (40 -42).…”

mentioning

confidence: 99%

Rkr1/Ltn1 Ubiquitin Ligase-mediated Degradation of Translationally Stalled Endoplasmic Reticulum Proteins

Crowder

Geigges

Gibson

et al. 2015

Journal of Biological Chemistry

Self Cite

View full text Add to dashboard Cite

Background: Translationally stalled proteins (including those aberrantly translated beyond their stop codons) pose dangers for eukaryotic cells. Results: The ubiquitin ligase Rkr1/Ltn1 targets translationally stalled ER-associated proteins for degradation. Conclusion: Cytosolic and ER-associated translationally stalled proteins are targeted for destruction by related mechanisms. Significance: Mechanisms regulating the degradation of translationally stalled ER-associated proteins may represent therapeutic targets for human disease.

show abstract

The yeast ERAD-C ubiquitin ligase Doa10 recognizes an intramembrane degron

Abstract: In Saccharomyces cerevisiae, surprisingly, the transmembrane protein Sbh2, which harbors an intramembrane degron, is a substrate of the ubiquitin-protein ligase Doa10.

Cited by 81 publications

References 60 publications

Sequential Poly-ubiquitylation by Specialized Conjugating Enzymes Expands the Versatility of a Quality Control Ubiquitin Ligase

Sequential Poly-ubiquitylation by Specialized Conjugating Enzymes Expands the Versatility of a Quality Control Ubiquitin Ligase

A Conserved C-terminal Element in the Yeast Doa10 and Human MARCH6 Ubiquitin Ligases Required for Selective Substrate Degradation

Rkr1/Ltn1 Ubiquitin Ligase-mediated Degradation of Translationally Stalled Endoplasmic Reticulum Proteins

Contact Info

Product

Resources

About