scholarly journals Implications of critical nodes-dependent unidirectional cross-talk between Plasmodium and Human SUMO

2021 ◽  
Author(s):  
Ram Kumar Mishra ◽  
Jai Shankar Singh ◽  
Sajeev T K ◽  
Rajlaxmi Panigrahi ◽  
Pearl Cherry ◽  
...  

The endoparasitic pathogen, Plasmodium falciparum (Pf), modulates protein-protein interactions to employ post-translational modifications like SUMOylation in order to establish successful infections. The interaction between E1 and E2 (Ubc9) enzymes governs species specificity in the Plasmodium SUMOylation pathway. Here, we demonstrate that a unidirectional cross-species interaction exists between Pf-SUMO and Human-E2, whereas Hs-SUMO1 failed to interact with Pf-E2. Biochemical and biophysical analysis revealed that surface-accessible Aspartates of Pf-SUMO determine the efficacy and specificity of SUMO-Ubc9 interactions. Furthermore, we demonstrate that critical residues of the Pf-Ubc9 N-terminal are responsible for the lack of interaction between Hs-SUMO1 and Pf-Ubc9. Mutating these residues to corresponding Hs-Ubc9 residues restore electrostatic,pi-pi, and hydrophobic interactions and allows efficient cross-species interactions. We suggest that the critical changes acquired on the surfaces of Plasmodium SUMO and Ubc9 proteins as nodes can help Plasmodium exploit the host SUMOylation machinery. Thus, Pf-SUMO interactions can be targeted for developing antimalarials.

2020 ◽  
Vol 27 (37) ◽  
pp. 6306-6355 ◽  
Author(s):  
Marian Vincenzi ◽  
Flavia Anna Mercurio ◽  
Marilisa Leone

Background:: Many pathways regarding healthy cells and/or linked to diseases onset and progression depend on large assemblies including multi-protein complexes. Protein-protein interactions may occur through a vast array of modules known as protein interaction domains (PIDs). Objective:: This review concerns with PIDs recognizing post-translationally modified peptide sequences and intends to provide the scientific community with state of art knowledge on their 3D structures, binding topologies and potential applications in the drug discovery field. Method:: Several databases, such as the Pfam (Protein family), the SMART (Simple Modular Architecture Research Tool) and the PDB (Protein Data Bank), were searched to look for different domain families and gain structural information on protein complexes in which particular PIDs are involved. Recent literature on PIDs and related drug discovery campaigns was retrieved through Pubmed and analyzed. Results and Conclusion:: PIDs are rather versatile as concerning their binding preferences. Many of them recognize specifically only determined amino acid stretches with post-translational modifications, a few others are able to interact with several post-translationally modified sequences or with unmodified ones. Many PIDs can be linked to different diseases including cancer. The tremendous amount of available structural data led to the structure-based design of several molecules targeting protein-protein interactions mediated by PIDs, including peptides, peptidomimetics and small compounds. More studies are needed to fully role out, among different families, PIDs that can be considered reliable therapeutic targets, however, attacking PIDs rather than catalytic domains of a particular protein may represent a route to obtain selective inhibitors.


2021 ◽  
Vol 17 (5) ◽  
pp. e1008988
Author(s):  
Nikolina ŠoŠtarić ◽  
Vera van Noort

Post-translational modifications (PTMs) play a vital, yet often overlooked role in the living cells through modulation of protein properties, such as localization and affinity towards their interactors, thereby enabling quick adaptation to changing environmental conditions. We have previously benchmarked a computational framework for the prediction of PTMs’ effects on the stability of protein-protein interactions, which has molecular dynamics simulations followed by free energy calculations at its core. In the present work, we apply this framework to publicly available data on Saccharomyces cerevisiae protein structures and PTM sites, identified in both normal and stress conditions. We predict proteome-wide effects of acetylations and phosphorylations on protein-protein interactions and find that acetylations more frequently have locally stabilizing roles in protein interactions, while the opposite is true for phosphorylations. However, the overall impact of PTMs on protein-protein interactions is more complex than a simple sum of local changes caused by the introduction of PTMs and adds to our understanding of PTM cross-talk. We further use the obtained data to calculate the conformational changes brought about by PTMs. Finally, conservation of the analyzed PTM residues in orthologues shows that some predictions for yeast proteins will be mirrored to other organisms, including human. This work, therefore, contributes to our overall understanding of the modulation of the cellular protein interaction networks in yeast and beyond.


BMC Genomics ◽  
2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Humza A. Khan ◽  
Manish J. Butte

Abstract Background Inborn errors of immunity (IEI) are a group of genetic disorders that impair the immune system, with over 400 genes described so far, and hundreds more to be discovered. To facilitate the search for new genes, we need a way to prioritize among all the genes in the genome those most likely to play an important role in immunity. Results Here we identify a new list of genes by linking known IEI genes to new ones by using open-source databases of protein-protein interactions, post-translational modifications, and transcriptional regulation. We analyze this new set of 2,530 IEI-related genes for their tolerance of genetic variation and by their expression levels in various immune cell types. Conclusions By merging genes derived from protein interactions of known IEI genes with transcriptional data, we offer a new list of candidate genes that may play a role in as-yet undiscovered IEIs.


Toxins ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 207 ◽  
Author(s):  
Stephen R. Johnson ◽  
Hillary G. Rikli

Research in toxinology has created a pharmacological paradox. With an estimated 220,000 venomous animals worldwide, the study of peptidyl toxins provides a vast number of effector molecules. However, due to the complexity of the protein-protein interactions, there are fewer than ten venom-derived molecules on the market. Structural characterization and identification of post-translational modifications are essential to develop biological lead structures into pharmaceuticals. Utilizing advancements in mass spectrometry, we have created a high definition approach that fuses conventional high-resolution MS-MS with ion mobility spectrometry (HDMSE) to elucidate these primary structure characteristics. We investigated venom from ten species of “tiger” spider (Genus: Poecilotheria) and discovered they contain isobaric conformers originating from non-enzymatic Asp isomerization. One conformer pair conserved in five of ten species examined, denominated PcaTX-1a and PcaTX-1b, was found to be a 36-residue peptide with a cysteine knot, an amidated C-terminus, and isoAsp33Asp substitution. Although the isomerization of Asp has been implicated in many pathologies, this is the first characterization of Asp isomerization in a toxin and demonstrates the isomerized product’s diminished physiological effects. This study establishes the value of a HDMSE approach to toxin screening and characterization.


Proteomes ◽  
2020 ◽  
Vol 8 (3) ◽  
pp. 14 ◽  
Author(s):  
Emmalyn J. Dupree ◽  
Madhuri Jayathirtha ◽  
Hannah Yorkey ◽  
Marius Mihasan ◽  
Brindusa Alina Petre ◽  
...  

Proteomics is the field of study that includes the analysis of proteins, from either a basic science prospective or a clinical one. Proteins can be investigated for their abundance, variety of proteoforms due to post-translational modifications (PTMs), and their stable or transient protein–protein interactions. This can be especially beneficial in the clinical setting when studying proteins involved in different diseases and conditions. Here, we aim to describe a bottom-up proteomics workflow from sample preparation to data analysis, including all of its benefits and pitfalls. We also describe potential improvements in this type of proteomics workflow for the future.


2019 ◽  
Vol 70 (13) ◽  
pp. 3401-3414 ◽  
Author(s):  
Clara Williams ◽  
Patricia Fernández-Calvo ◽  
Maite Colinas ◽  
Laurens Pauwels ◽  
Alain Goossens

Abstract Phytohormones regulate the plasticity of plant growth and development, and responses to biotic and abiotic stresses. Many hormone signal transduction cascades involve ubiquitination and subsequent degradation of proteins by the 26S proteasome. The conjugation of ubiquitin to a substrate is facilitated by the E1 activating, E2 conjugating, and the substrate-specifying E3 ligating enzymes. The most prevalent type of E3 ligase in plants is the Cullin–RING ligase (CRL)-type, with F-box proteins (FBPs) as the substrate recognition component. The activity of these SKP–Cullin–F-box (SCF) complexes needs to be tightly regulated in time and place. Here, we review the regulation of SCF function in plants on multiple levels, with a focus on the auxin and jasmonate SCF-type receptor complexes. We discuss in particular the relevance of protein–protein interactions and post-translational modifications as mechanisms to keep SCF functioning under control. Additionally, we highlight the unique property of SCFTIR1/AFB and SCFCOI1 to recognize substrates by forming co-receptor complexes. Finally, we explore how engineered selective agonists can be used to study and uncouple the outcomes of the complex auxin and jasmonate signaling networks that are governed by these FBPs.


2003 ◽  
Vol 162 (2) ◽  
pp. 317-327 ◽  
Author(s):  
Tim-Wolf Gilberger ◽  
Jennifer K. Thompson ◽  
Michael B. Reed ◽  
Robert T. Good ◽  
Alan F. Cowman

The invasion of host cells by the malaria parasite Plasmodium falciparum requires specific protein–protein interactions between parasite and host receptors and an intracellular translocation machinery to power the process. The transmembrane erythrocyte binding protein-175 (EBA-175) and thrombospondin-related anonymous protein (TRAP) play central roles in this process. EBA-175 binds to glycophorin A on human erythrocytes during the invasion process, linking the parasite to the surface of the host cell. In this report, we show that the cytoplasmic domain of EBA-175 encodes crucial information for its role in merozoite invasion, and that trafficking of this protein is independent of this domain. Further, we show that the cytoplasmic domain of TRAP, a protein that is not expressed in merozoites but is essential for invasion of liver cells by the sporozoite stage, can substitute for the cytoplasmic domain of EBA-175. These results show that the parasite uses the same components of its cellular machinery for invasion regardless of the host cell type and invasive form.


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