scholarly journals Combinatorial phosphorylation modulates the structure and function of the G protein γ subunit in yeast

2021 ◽  
Vol 14 (688) ◽  
pp. eabd2464
Author(s):  
Zahra Nassiri Toosi ◽  
Xinya Su ◽  
Ruth Austin ◽  
Shilpa Choudhury ◽  
Wei Li ◽  
...  
Keyword(s):  
G Protein ◽  
Posttranslational Modifications ◽  
Intrinsically Disordered Proteins ◽  
Structure And Function ◽  
Disordered Proteins ◽  
Intrinsically Disordered ◽  
Intrinsically Disordered Regions ◽  
Gpcr Activation ◽  
Essential Components ◽  
And Function

Intrinsically disordered regions (IDRs) in proteins are often targets of combinatorial posttranslational modifications, which serve to regulate protein structure and function. Emerging evidence suggests that the N-terminal tails of G protein γ subunits, which are essential components of heterotrimeric G proteins, are intrinsically disordered, phosphorylation-dependent determinants of G protein signaling. Here, we found that the yeast Gγ subunit Ste18 underwent combinatorial, multisite phosphorylation events within its N-terminal IDR. G protein–coupled receptor (GPCR) activation and osmotic stress induced phosphorylation at Ser7, whereas glucose and acid stress induced phosphorylation at Ser3, which was a quantitative indicator of intracellular pH. Each site was phosphorylated by a distinct set of kinases, and phosphorylation of one site affected phosphorylation of the other, as determined through exposure to serial stimuli and through phosphosite mutagenesis. Last, we showed that phosphorylation resulted in changes in IDR structure and that different combinations of phosphorylation events modulated the activation rate and amplitude of the downstream mitogen-activated protein kinase Fus3. These data place Gγ subunits among intrinsically disordered proteins that undergo combinatorial posttranslational modifications that govern signaling pathway output.

scholarly journals Combinatorial phosphorylation modulates the structure and function of the G protein gamma subunit in yeast

2020 ◽  
Author(s):  
Zahra Nassiri Toosi ◽  
Xinya Su ◽  
Shilpa Choudhury ◽  
Wei Li ◽  
Yui Tik Pang ◽  
...  
Keyword(s):  
G Protein ◽  
Intrinsically Disordered Proteins ◽  
Protein Complexes ◽  
Disordered Proteins ◽  
Post Translational Modification ◽  
Intrinsically Disordered ◽  
Intrinsically Disordered Regions ◽  
Gpcr Activation ◽  
Essential Components ◽  
And Function

AbstractProtein intrinsically disordered regions (IDRs) are often targets of combinatorial post-translational modifications (PTMs) that serve to regulate protein structure and/or function. Emerging evidence suggests that the N-terminal tails of G protein γ subunits – essential components of heterotrimeric G protein complexes – are intrinsically disordered, highly phosphorylated governors of G protein signaling. Here, we demonstrate that the yeast Gγ Ste18 undergoes combinatorial, multi-site phosphorylation within its N-terminal IDR. Phosphorylation at S7 is responsive to GPCR activation and osmotic stress while phosphorylation at S3 is responsive to glucose stress and is a quantitative indicator of intracellular pH. Each site is phosphorylated by a distinct set of kinases and both are also interactive, such that phosphomimicry at one site affects phosphorylation on the other. Lastly, we show that phosphorylation produces subtle yet clear changes in IDR structure and that different combinations of phosphorylation modulate the activation rate and amplitude of the scaffolded MAPK Fus3. These data place Gγ subunits among the growing list of intrinsically disordered proteins that exploit combinatorial post-translational modification to govern signaling pathway output.

scholarly journals Structural Proteomics Methods to Interrogate the Conformations and Dynamics of Intrinsically Disordered Proteins

2021 ◽  
Vol 9 ◽  
Author(s):  
Rebecca Beveridge ◽  
Antonio N. Calabrese
Keyword(s):  
Posttranslational Modifications ◽  
Intrinsically Disordered Proteins ◽  
Structure And Function ◽  
Disordered Proteins ◽  
Structural Proteomics ◽  
Intrinsically Disordered ◽  
Folded Proteins ◽  
Structural Mass Spectrometry ◽  
And Function ◽  
Structural Mass

Intrinsically disordered proteins (IDPs) and regions of intrinsic disorder (IDRs) are abundant in proteomes and are essential for many biological processes. Thus, they are often implicated in disease mechanisms, including neurodegeneration and cancer. The flexible nature of IDPs and IDRs provides many advantages, including (but not limited to) overcoming steric restrictions in binding, facilitating posttranslational modifications, and achieving high binding specificity with low affinity. IDPs adopt a heterogeneous structural ensemble, in contrast to typical folded proteins, making it challenging to interrogate their structure using conventional tools. Structural mass spectrometry (MS) methods are playing an increasingly important role in characterizing the structure and function of IDPs and IDRs, enabled by advances in the design of instrumentation and the development of new workflows, including in native MS, ion mobility MS, top-down MS, hydrogen-deuterium exchange MS, crosslinking MS, and covalent labeling. Here, we describe the advantages of these methods that make them ideal to study IDPs and highlight recent applications where these tools have underpinned new insights into IDP structure and function that would be difficult to elucidate using other methods.

scholarly journals Intrinsically disordered proteins identified in the aggregate proteome serve as biomarkers of neurodegeneration

2021 ◽  
Author(s):  
Srinivas Ayyadevara ◽  
Akshatha Ganne ◽  
Meenakshisundaram Balasubramaniam ◽  
Robert J. Shmookler Reis
Keyword(s):  
Intrinsically Disordered Proteins ◽  
Protein Complexes ◽  
Disordered Proteins ◽  
Intrinsically Disordered ◽  
Intrinsically Disordered Regions ◽  
Physiological Processes ◽  
Protein Partners ◽  
And Function ◽  
Computational Analyses ◽  
Disordered Regions

AbstractA protein’s structure is determined by its amino acid sequence and post-translational modifications, and provides the basis for its physiological functions. Across all organisms, roughly a third of the proteome comprises proteins that contain highly unstructured or intrinsically disordered regions. Proteins comprising or containing extensive unstructured regions are referred to as intrinsically disordered proteins (IDPs). IDPs are believed to participate in complex physiological processes through refolding of IDP regions, dependent on their binding to a diverse array of potential protein partners. They thus play critical roles in the assembly and function of protein complexes. Recent advances in experimental and computational analyses predicted multiple interacting partners for the disordered regions of proteins, implying critical roles in signal transduction and regulation of biological processes. Numerous disordered proteins are sequestered into aggregates in neurodegenerative diseases such as Alzheimer’s disease (AD) where they are enriched even in serum, making them good candidates for serum biomarkers to enable early detection of AD.

Intrinsic disorder in proteins: a challenge for (un)structural biology met by ion mobility–mass spectrometry

2012 ◽  
Vol 40 (5) ◽  
pp. 1021-1026 ◽  
Author(s):  
Ewa Jurneczko ◽  
Faye Cruickshank ◽  
Massimiliano Porrini ◽  
Penka Nikolova ◽  
Iain D.G. Campuzano ◽  
...  
Keyword(s):  
Ion Mobility ◽  
Intrinsically Disordered Proteins ◽  
Three Dimensional ◽  
Disordered Proteins ◽  
Intrinsically Disordered ◽  
Intrinsically Disordered Regions ◽  
New Methods ◽  
Binding Partners ◽  
Nanoelectrospray Ionization ◽  
And Function

The link between structure and function of a given protein is a principal tenet of biology. The established approach to understand the function of a protein is to ‘solve’ its structure and subsequently investigate interactions between the protein and its binding partners. However, structure determination via crystallography or NMR is challenging for proteins where localized regions or even their entire structure fail to fold into a three-dimensional form. These so called IDPs (intrinsically disordered proteins) or intrinsically disordered regions constitute up to 40% of all expressed proteins, and a much higher percentage in proteins involved in the proliferation of cancer. For these proteins, there is a need to develop new methods for structural characterization which exploit their biophysical properties. IM (ion mobility)–MS is uniquely able to examine both absolute conformation(s), populations of conformation and also conformational change, and is therefore highly applicable to the study of IDPs. The present article details the technique of IM–MS and illustrates its use in assessing the relative disorder of the wild-type p53 DNA-core-binding domain of cellular tumour antigen p53. The IM data were acquired on a Waters Synapt HDMS instrument following nESI (nanoelectrospray ionization) from ‘native’ and low-pH solution conditions.

scholarly journals Disorder in a two-domain neuronal Ca2+-binding protein regulates domain stability and dynamics using ligand mimicry

2020 ◽  
Author(s):  
Lasse Staby ◽  
Katherine R. Kemplen ◽  
Amelie Stein ◽  
Michael Ploug ◽  
Jane Clarke ◽  
...  
Keyword(s):  
Intrinsically Disordered Proteins ◽  
Three Dimensional ◽  
Life Time ◽  
Disordered Proteins ◽  
Intrinsically Disordered ◽  
Order And Disorder ◽  
C Terminus ◽  
Close Relationship ◽  
Stability Dynamics ◽  
And Function

Abstract Understanding the interplay between sequence, structure and function of proteins has been complicated in recent years by the discovery of intrinsically disordered proteins (IDPs), which perform biological functions in the absence of a well-defined three-dimensional fold. Disordered protein sequences account for roughly 30% of the human proteome and in many proteins, disordered and ordered domains coexist. However, few studies have assessed how either feature affects the properties of the other. In this study, we examine the role of a disordered tail in the overall properties of the two-domain, calcium-sensing protein neuronal calcium sensor 1 (NCS-1). We show that loss of just six of the 190 residues at the flexible C-terminus is sufficient to severely affect stability, dynamics, and folding behavior of both ordered domains. We identify specific hydrophobic contacts mediated by the disordered tail that may be responsible for stabilizing the distal N-terminal domain. Moreover, sequence analyses indicate the presence of an LSL-motif in the tail that acts as a mimic of native ligands critical to the observed order–disorder communication. Removing the disordered tail leads to a shorter life-time of the ligand-bound complex likely originating from the observed destabilization. This close relationship between order and disorder may have important implications for how investigations into mixed systems are designed and opens up a novel avenue of drug targeting exploiting this type of behavior.

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