Dataset Information

The UBA-domain of Ubc1/Ube2K Facilitates the Assembly of K48-/K63-Branched Ubiquitin Chains

ABSTRACT: Assembly of polymeric ubiquitin (Ub) chains is an essential posttranslational protein modification that regulates widespread intracellular processes in eukaryotic cells. Factors and mechanisms that regulate the formation of Ub chains are key to the understanding of many cellular processes. The E2 enzyme Ubc1 (Ube2K) exclusively targets K48 in Ub for chain formation and has been linked to cell-cycle progression and proteostasis. Uniquely among E2 enzymes, it harbors a Ub binding UBA domain, which has been implicated in Ub chain formation but its function remained elusive. Through in vitro binding experiments, we unexpectedly found that the UBA domain enables preferential binding of K63-linked Ub chains. Based on structural modeling, extensive in vitro ubiquitination experiments and NMR binding studies, we propose a mechanism through which Ubc1 selectively forms K48/K63 branched Ub chains – an usual chain architecture, about whose prevalence and function little is known to date. Ultimately, we link UBA dependent activity of Ubc1 to its role in proteostasis through genetic experiments.

INSTRUMENT(S): Q Exactive

ORGANISM(S): Saccharomyces Cerevisiae (baker's Yeast)

TISSUE(S): Cell Suspension Culture

SUBMITTER: Henrik Zauber

LAB HEAD: Matthias Selbach

PROVIDER: PXD018651 | Pride | 2021-09-09

REPOSITORIES: Pride

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Publications

The UBA domain of conjugating enzyme Ubc1/Ube2K facilitates assembly of K48/K63-branched ubiquitin chains.

Pluska Lukas L Jarosch Ernst E Zauber Henrik H Kniss Andreas A Waltho Anita A Bagola Katrin K von Delbrück Maximilian M Löhr Frank F Schulman Brenda A BA Selbach Matthias M Dötsch Volker V Sommer Thomas T

The EMBO journal 20210212 6

The assembly of a specific polymeric ubiquitin chain on a target protein is a key event in the regulation of numerous cellular processes. Yet, the mechanisms that govern the selective synthesis of particular polyubiquitin signals remain enigmatic. The homologous ubiquitin-conjugating (E2) enzymes Ubc1 (budding yeast) and Ube2K (mammals) exclusively generate polyubiquitin linked through lysine 48 (K48). Uniquely among E2 enzymes, Ubc1 and Ube2K harbor a ubiquitin-binding UBA domain with unknown f ...[more]

PMID: 33576509

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Project description:BS69 (aka ZMYND11) was initially discovered as a direct target of adenoviral E1A oncoprotein1. Subsequent studies implicated BS69 as a tumor suppressor and a transcriptional regulator2. But exactly how BS69 regulates gene expression has remained elusive. BS69 contains tandemly arranged PHD, BROMO and PWWP domains, which are known to function as chromatin recognition modalities. Here we show that BS69 selectively recognizes histone variant H3.3 lysine 36 trimethylation (H3.3K36me3) via these chromatin recognition modules. Using a proteomics approach, we further identified association of BS69 with a host of RNA splicing regulators including EFTUD2 and other U5 snRNP components of the spliceosome. Remarkably, RNA-seq analysis shows that BS69 mainly regulates intron retention (IR), which is one of the least well-understood RNA alternative splicing events in mammalian cells. Specifically, loss of BS69 results in a decrease in IR, while in contrast, knockdown of EFTUD2 leads to an increase in IR, consistent with its role as a core member of the splicesome machinery. Importantly, wildtype BS69, but not a BS69 mutant defective in its interaction with EFTUD2, rescues the IR events. We also show that knockdown of SETD2, the main enzyme that mediates H3K36 trimethylation3, similarly results in a decreased retention of the same introns regulated by BS69. Significantly, a BS69 mutant unable to bind H3.3K36me3 in vitro fails to rescue the reduced IR phenotype associated with the loss of BS69. Taken together, our findings identify an antagonistic relationship between BS69 and the core splicing machinery and demonstrate that BS69-mediated RNA splicing regulation is dependent both on its ability to bind chromatin decorated by H3K36me3 and its ability to physically interact with the core spliceosome machinery. Our study reveals a novel and unexpected role of BS69 in connecting histone H3.3K36 trimethylation to regulated RNA splicing, providing significant new insights into chromatin regulation of RNA splicing. HeLaS cells stably expressing BS69 were used for HA-tagged BS69 ChIP-seq. HeLa cells were used for BS69 ChIP-seq. HeLa cells were used for H3K36me3 ChIP-seq.

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Dataset Information

The UBA-domain of Ubc1/Ube2K Facilitates the Assembly of K48-/K63-Branched Ubiquitin Chains

Publications

The UBA domain of conjugating enzyme Ubc1/Ube2K facilitates assembly of K48/K63-branched ubiquitin chains.

Similar Datasets

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