Phosphorylation of an Intrinsically Disordered Segment in Ets1 Shifts Conformational Sampling toward Binding-Competent Substates

Bui, Jennifer M.; Gsponer, Jörg

doi:10.1016/j.str.2014.06.002

Cited by 19 publications

(13 citation statements)

References 28 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“… 24 ), Cdc25A and Cdc25B phosphatases 25 26 . In a recent molecular dynamics study, it was also shown that phosphorylation of a disordered segment shifts the conformational equilibrium towards binding competent sub-states 27 .…”

Section: Resultsmentioning

confidence: 98%

Tripartite degrons confer diversity and specificity on regulated protein degradation in the ubiquitin-proteasome system

et al. 2016

View full text Add to dashboard Cite

Specific signals (degrons) regulate protein turnover mediated by the ubiquitin-proteasome system. Here we systematically analyse known degrons and propose a tripartite model comprising the following: (1) a primary degron (peptide motif) that specifies substrate recognition by cognate E3 ubiquitin ligases, (2) secondary site(s) comprising a single or multiple neighbouring ubiquitinated lysine(s) and (3) a structurally disordered segment that initiates substrate unfolding at the 26S proteasome. Primary degron sequences are conserved among orthologues and occur in structurally disordered regions that undergo E3-induced folding-on-binding. Posttranslational modifications can switch primary degrons into E3-binding-competent states, thereby integrating degradation with signalling pathways. Degradation-linked lysines tend to be located within disordered segments that also initiate substrate degradation by effective proteasomal engagement. Many characterized mutations and alternative isoforms with abrogated degron components are implicated in disease. These effects result from increased protein stability and interactome rewiring. The distributed nature of degrons ensures regulation, specificity and combinatorial control of degradation.

show abstract

Section: Resultsmentioning

confidence: 98%

Tripartite degrons confer diversity and specificity on regulated protein degradation in the ubiquitin-proteasome system

et al. 2016

View full text Add to dashboard Cite

show abstract

“…The literature reports many exceptions to the PPII target for SH3-domain interaction, such as 3 10 -helices, but these structures were observed by X-ray crystallography of peptide-SH3-domain complexes that were better-behaved than the one studied here [ 27 , 36 , 72 ]. We consider that a more realistic scenario here is that MBP samples a variety of conformations within the SH3-domain pocket, and that these are modulated by post-translational modifications, such as phosphorylation by MAPKs at T92 and T95 [ 8 , 73 ]. Although it was expected here that the proline-rich segment of this IDP would form a PPII conformation [ 41 ], there are exceptions to this model [ 74 ].…”

Section: Discussionmentioning

confidence: 99%

The proline-rich region of 18.5 kDa myelin basic protein binds to the SH3-domain of Fyn tyrosine kinase with the aid of an upstream segment to form a dynamic complexin vitro

et al. 2014

View full text Add to dashboard Cite

The intrinsically disordered 18.5 kDa classic isoform of MBP (myelin basic protein) interacts with Fyn kinase during oligodendrocyte development and myelination. It does so primarily via a central proline-rich SH3 (Src homology 3) ligand (T92–R104, murine 18.5 kDa MBP sequence numbering) that is part of a molecular switch due to its high degree of conservation and modification by MAP (mitogen-activated protein) and other kinases, especially at residues T92 and T95. Here, we show using co-transfection experiments of an early developmental oligodendroglial cell line (N19) that an MBP segment upstream of the primary ligand is involved in MBP–Fyn–SH3 association in cellula. Using solution NMR spectroscopy in vitro, we define this segment to comprise MBP residues (T62–L68), and demonstrate further that residues (V83–P93) are the predominant SH3-target, assessed by the degree of chemical shift change upon titration. We show by chemical shift index analysis that there is no formation of local poly-proline type II structure in the proline-rich segment upon binding, and by NOE (nuclear Overhauser effect) and relaxation measurements that MBP remains dynamic even while complexed with Fyn–SH3. The association is a new example first of a non-canonical SH3-domain interaction and second of a fuzzy MBP complex.

show abstract

“…Phosphorylation in disordered regions can modulate local conformational preferences such that bound-state-like pre-structuring is observed (81). Thus, priming modifications in disordered regions can serve to achieve specificity for E3 recognition, using a signaling event as a trigger and thereby achieving temporal and signal-dependent binding specificity.…”

Section: Disordered Primary Degrons Are Regulated By Ptms Within Degrmentioning

confidence: 99%

Design Principles Involving Protein Disorder Facilitate Specific Substrate Selection and Degradation by the Ubiquitin-Proteasome System

Guharoy

Bhowmick

Tompa

2016

Journal of Biological Chemistry

View full text Add to dashboard Cite

The ubiquitin-proteasome system (UPS) regulates diverse cellular pathways by the timely removal (or processing) of proteins. Here we review the role of structural disorder and conformational flexibility in the different aspects of degradation. First, we discuss post-translational modifications within disordered regions that regulate E3 ligase localization, conformation, and enzymatic activity, and also the role of flexible linkers in mediating ubiquitin transfer and reaction processivity. Next we review well studied substrates and discuss that substrate elements (degrons) recognized by E3 ligases are highly disordered: short linear motifs recognized by many E3s constitute an important class of degrons, and these are almost always present in disordered regions. Substrate lysines targeted for ubiquitination are also often located in neighboring regions of the E3 docking motifs and are therefore part of the disordered segment. Finally, biochemical experiments and predictions show that initiation of degradation at the 26S proteasome requires a partially unfolded region to facilitate substrate entry into the proteasomal core.Many cellular pathways and regulatory networks require spatial and temporal control of effector protein levels. Regulated degradation mediated by the ubiquitin-proteasome system (UPS) 3 is an important post-translational mechanism that helps to achieve precise fine-tuning of protein levels and is being increasingly linked to more and more pathways. The UPS is the major intracellular degradation pathway that has evolved into a complex system consisting of several hundred dedicated components (1). Important examples of regulated degradation include cell cycle regulatory proteins (e.g. cyclins, cyclin-dependent kinase inhibitors, etc.) that need to be degraded or inactivated before cell cycle checkpoint mechanisms decide upon progress (2, 3). Transcription factors (e.g. mammalian Myc, Jun, E2-F, p53, etc.) that activate gene expression triggered by specific stimuli are usually maintained at low levels (4, 5); further, the ubiquitin system also triggers processing (by limited proteolysis) and activation of transcription factors such as NFB (6). Cell surface growth factor/hormone receptors undergo internalization and degradation to switch off signaling inputs (7-12). The UPS also tightly regulates other key intracellular effectors (e.g. Smad proteins, Bcl-2) of signaling pathways (13-15). Not surprisingly, defects in regulated degradation are being linked to increasing numbers of diseases, including neurodegeneration and cancer, making the UPS very attractive for drug design (16 -19).Ubiquitination is organized as a cascade of E1 (ubiquitinactivating), E2 (ubiquitin-conjugating), and E3 (ubiquitin ligase) enzymes. The pathway is strongly conserved from yeast to mammals. The E1-E2-E3 axis has a pyramidal structure, with 2 E1 proteins (in humans), 30 -40 E2 enzymes, and Ͼ600 E3 ligases (20). E3s are subclassified into major groups based on their subunit organization and domain composition ( Fig. 1) (21,...

show abstract

Phosphorylation of an Intrinsically Disordered Segment in Ets1 Shifts Conformational Sampling toward Binding-Competent Substates

Cited by 19 publications

References 28 publications

Tripartite degrons confer diversity and specificity on regulated protein degradation in the ubiquitin-proteasome system

Tripartite degrons confer diversity and specificity on regulated protein degradation in the ubiquitin-proteasome system

The proline-rich region of 18.5 kDa myelin basic protein binds to the SH3-domain of Fyn tyrosine kinase with the aid of an upstream segment to form a dynamic complexin vitro

Design Principles Involving Protein Disorder Facilitate Specific Substrate Selection and Degradation by the Ubiquitin-Proteasome System

Contact Info

Product

Resources

About