Dataset Information

Ataxin-3 deubiquitination is coupled to Parkin ubiquitination via E2 ubiquitin-conjugating enzyme.

ABSTRACT: We reported previously that parkin, a Parkinson disease-associated E3 ubiquitin-ligase interacts with ataxin-3, a deubiquitinating enzyme associated with Machado-Joseph disease. Ataxin-3 was found to counteract parkin self-ubiquitination both in vitro and in cells. Moreover, ataxin-3-dependent deubiquitination of parkin required the catalytic cysteine 14 in ataxin-3, although the precise mechanism remained unclear. We report here that ataxin-3 interferes with the attachment of ubiquitin (Ub) onto parkin in real-time during conjugation but is unable to hydrolyze previously assembled parkin-Ub conjugates. The mechanism involves an ataxin-3-dependent stabilization of the complex between parkin and the E2 Ub-conjugating enzyme, which impedes the efficient charging of the E2 with Ub. Moreover, within this complex, the transfer of Ub from the E2 is diverted away from parkin and onto ataxin-3, further explaining how ataxin-3 deubiquitination is coupled to parkin ubiquitination. Taken together, our findings reveal an unexpected convergence upon the E2 Ub-conjugating enzyme in the regulation of an E3/deubiquitinating enzyme pair, with important implications for the function of parkin and ataxin-3, two proteins responsible for closely related neurodegenerative diseases.

SUBMITTER: Durcan TM

PROVIDER: S-EPMC3249107 | biostudies-literature | 2012 Jan

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Ataxin-3 deubiquitination is coupled to Parkin ubiquitination via E2 ubiquitin-conjugating enzyme.

Durcan Thomas M TM Kontogiannea Maria M Bedard Nathalie N Wing Simon S SS Fon Edward A EA

The Journal of biological chemistry 20111111 1

We reported previously that parkin, a Parkinson disease-associated E3 ubiquitin-ligase interacts with ataxin-3, a deubiquitinating enzyme associated with Machado-Joseph disease. Ataxin-3 was found to counteract parkin self-ubiquitination both in vitro and in cells. Moreover, ataxin-3-dependent deubiquitination of parkin required the catalytic cysteine 14 in ataxin-3, although the precise mechanism remained unclear. We report here that ataxin-3 interferes with the attachment of ubiquitin (Ub) ont ...[more]

PMID: 22081612

Similar Datasets

Project description:The Androgen Receptor (AR) is a pivotal protein in human physiology, exerting significant influence on both male and female physiology (PMID: 18434134, 25905231). Functioning as a nuclear transcription factor, AR binds to testosterone, translocates to the nucleus, and subsequently regulates the expression of numerous genes, impacting vital cellular processes such as cell proliferation, differentiation, and apoptosis (PMID: 4810760, 25237629). The prominent role of AR in human physiology is particularly notable in the context of prostate cancer initiation, where aberrant AR signaling has been identified as a key driver in tumorigenesis (PMID: 4810760, 27057074, 37429011). However, despite the considerable success of the current anti-androgen therapeutic approach, it faces the formidable challenge of drug resistance, significantly limiting the clinical outcome for patients and necessitating the urgent development of new therapeutic approaches to overcome resistance (PMID: 26563462, 24881730, 31363002, 35582713). Notably, one key feature of antiandrogen resistance is the sustained or enhanced AR signaling observed in many resistant tumors (PMID: 26563462, 34449248, 23580326), although the underlying molecular mechanisms remain largely unclear. Protein degradation, with ubiquitination at its core, plays a critical role in cell functionality, ensuring the elimination of redundant and harmful proteins (PMID: 16738015, 33634825). This intricate process involves the attachment of small proteins called ubiquitin to target proteins, marking them for degradation. Dysregulation of ubiquitination can lead to the accumulation of oncogenic proteins, contributing to tumorigenesis and therapy resistance in various cancers (PMID: 32296023, 33004065). The degradation of proteins is a complex process that involves the coordination of E1, E2 and E3 enzymes, with E3 enzymes binding to the target protein (PMID: 21111229, 20930542). Logically, research has focused on finding E3s targeting AR for degradation but has overlooked the role that E2s play in the ubiquitination process. In recent years, E2s have been shown to dictate the how and where ubiquitin gets attached in the target protein, dictating the fate of the protein (PMID: 27002219, 19851334). Therefore, finding the E2 involved in the degradation of AR can prove to be essential. In this study, we conducted an in vivo library screening approach and identified UBE2J1 as the bona fide E2 ubiquitin conjugating enzyme for AR ubiquitination. Our results demonstrated that the frequent loss of UBE2J1 in prostate cancer leads to dysregulated and impaired AR ubiquitination and degradation. Consequently, this promotes the accumulation of AR proteins and confers resistance to antiandrogen treatment in UBE2J1-deficient prostate cancer cells. To address this, we developed an innovative ubiquitination-based AR degrader that effectively restores AR ubiquitination, thereby resensitizing prostate cancer cells to antiandrogen therapy. These findings not only unveil the pivotal role of UBE2J1 as the crucial E2 ubiquitin conjugating enzyme for AR degradation but also shed light on a novel mechanism through which advanced prostate cancer cells upregulate AR protein levels, thereby acquiring resistance to existing antiandrogen therapy. These novel insights hold the potential to inform the development of more effective therapeutic strategies against advanced prostate cancers.

Dataset Information

Ataxin-3 deubiquitination is coupled to Parkin ubiquitination via E2 ubiquitin-conjugating enzyme.

Publications

Ataxin-3 deubiquitination is coupled to Parkin ubiquitination via E2 ubiquitin-conjugating enzyme.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets