scholarly journals A Novel Phosphorylation Site-Kinase Network-Based Method for the Accurate Prediction of Kinase-Substrate Relationships

2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
Minghui Wang ◽  
Tao Wang ◽  
Binghua Wang ◽  
Yu Liu ◽  
Ao Li
Keyword(s):  
Protein Interactions ◽  
Phosphorylation Site ◽  
Prediction Performance ◽  
Accurate Prediction ◽  
Phosphorylation Sites ◽  
Protein Protein Interactions ◽  
Biological Mechanisms ◽  
Kinase Substrate ◽  
Prediction Tools ◽  
Local Sequence

Protein phosphorylation is catalyzed by kinases which regulate many aspects that control death, movement, and cell growth. Identification of the phosphorylation site-specific kinase-substrate relationships (ssKSRs) is important for understanding cellular dynamics and provides a fundamental basis for further disease-related research and drug design. Although several computational methods have been developed, most of these methods mainly use local sequence of phosphorylation sites and protein-protein interactions (PPIs) to construct the prediction model. While phosphorylation presents very complicated processes and is usually involved in various biological mechanisms, the aforementioned information is not sufficient for accurate prediction. In this study, we propose a new and powerful computational approach named KSRPred for ssKSRs prediction, by introducing a novel phosphorylation site-kinase network (pSKN) profiles that can efficiently incorporate the relationships between various protein kinases and phosphorylation sites. The experimental results show that the pSKN profiles can efficiently improve the prediction performance in collaboration with local sequence and PPI information. Furthermore, we compare our method with the existing ssKSRs prediction tools and the results demonstrate that KSRPred can significantly improve the prediction performance compared with existing tools.

scholarly journals Characterization of the Key Region and Key Phosphorylation Sites of EcaICE1 for its Molecular Interaction with EcaHOS1 Protein in Eucalyptus camaldulensis

2020 ◽  
Author(s):  
Ling Cheng ◽  
Weihua Zhang ◽  
Jianlin Hu ◽  
Ziyang Zhang ◽  
Yan Liu ◽  
...  
Keyword(s):  
Cold Stress ◽  
Protein Interactions ◽  
Phosphorylation Site ◽  
Eucalyptus Camaldulensis ◽  
Phosphorylation Sites ◽  
Protein Protein Interactions ◽  
Amino Acid Region ◽  
Mda Content ◽  
Proteasome Pathway

Abstract Background ICE1 (inducer of CBF expression 1), a MYC-like bHLH transcriptional activator, plays an important role in plant under cold stress via regulating transcriptional expression of downstream cold-responsive genes. Ubiquitination-proteasome pathway mediated by high expression of osmotically responsive gene1 (HOS1) can effectively induce the degradation of ICE1 and decrease the expression of expression of CBFs and their downstream genes under cold stress response in Arabidopsis , but the knowledge about ubiquitination regulation of ICE1 by HOS1 is still unknown in woody plants.Results The complete EcaICE1 gene and a new E3 ubiquitin ligase gene EcaHOS1 were amplified from the tissue culture seedlings of Eucalyptus camaldulensis . Yeast two-hybrid (Y2H) and BiFC assay results showed that EcaICE1 can interact with EcaHOS1 protein in the nucleus, and further Y2H assay demonstrated that the 126-185 amino acid region at the N-terminus of EcaICE1 protein was indispensable for its interaction with EcaHOS1 protein. Moreover, we found that the amino acids at positions 143, 145, 158 and 184 within the key interaction region were the potential phosphorylation sites of EcaICE1 based on bioinformatics analysis, and that only the substitution of Serine (Ser) 158 by Alanine (Ala) blocked the protein-protein interactions between EcaICE1 and EcaHOS1 by Y2H and β-galactosidase assays using site-direct mutagenesis. Overexpression of EcaICE1 and its mutations in Arabidopsis could significantly increase POD and SOD activities with a reduction for MDA content and up-regulate four cold-responsive genes ( CBF3 , KIN1 , COR15 and COR47A ) in the transgenic lines.Conclusion We first reported that EcaICE1 could interact with EcaHOS1 protein in Eucalyptus , and identified Ser 158 of EcaICE1 as the key phosphorylation site for its interaction with EcaHOS1 protein.

scholarly journals Using Multilayer Heterogeneous Networks to Infer Functions of Phosphorylated Sites

2020 ◽  
Author(s):  
Joanne Watson ◽  
Jean-Marc Schwartz ◽  
Chiara Francavilla
Keyword(s):  
Protein Interactions ◽  
Phosphorylation Site ◽  
Random Permutation ◽  
Phosphorylation Sites ◽  
Protein Protein Interactions ◽  
Functional Annotations ◽  
Cellular Processes ◽  
Context Specific ◽  
Pathway Databases ◽  
Permutation Analysis

AbstractMass spectrometry-based quantitative phosphoproteomics has become an essential approach in the study of cellular processes such as cell signaling. Commonly used methods to analyze phosphoproteomics datasets depend on generic, gene-centric annotations such as Gene Ontology terms and do not account for the function of a protein in a given phosphorylation state. Thus, analysis of phosphoproteomics data is hampered by a lack of phosphorylated site-specific annotations. Here, we propose a method that combines shotgun phosphoproteomics data, protein-protein interactions and functional annotations from ontologies or pathway databases into a heterogeneous multilayer network. Phosphorylation sites are then associated to potential functions using a random walk on heterogeneous network (RWHN) algorithm. We validated our approach using a dataset modelling the MAPK/ERK pathway and were able to associate differentially regulated sites on the same protein to their previously described functions. Random permutation analysis proved that these associations were not random and were determined by the network topology. We then applied the RWHN algorithm to two previously published datasets; the algorithm was able to reproduce the experimentally validated conclusions from the publications, and associate phosphorylation sites with both new and known functions based on their regulatory patterns. The approach described here provides a robust, phosphorylation site-centric method to analyzing phosphoproteomics data and identifying potential context-specific functions for sites with similar phosphorylation profiles.

scholarly journals Characterization of the Key Region and Phosphorylation Sites of EcaICE1 for its Molecular Interaction with EcaHOS1 Protein from Eucalyptus camaldulensis

2019 ◽  
Author(s):  
Ling Cheng ◽  
Weihua Zhang ◽  
Jianlin Hu ◽  
Ziyang Zhang ◽  
Yan Liu ◽  
...  
Keyword(s):  
Cold Stress ◽  
Protein Interactions ◽  
Phosphorylation Site ◽  
Eucalyptus Camaldulensis ◽  
Phosphorylation Sites ◽  
Protein Protein Interactions ◽  
Reading Frame ◽  
Amino Acid Region ◽  
Proteasome Pathway

AbstractICE1 (inducer of CBF expression 1), a MYC-like bHLH transcriptional activator, plays an important role in plant under cold stress via regulating transcriptional expression of downstream cold-responsive genes. Ubiquitination-proteasome pathway mediated by high expression of osmotically responsive gene1 (HOS1) can effectively induce the degradation of ICE1 and decrease the expression of expression of CBFs and their downstream genes under cold stress response in Arabidopsis, but the knowledge about ubiquitination regulation of ICE1 by HOS1 is still limited in woody plants. In this study, a complete open reading frame of EcaICE1 gene and EcaHOS1 was amplified from the tissue culture seedlings of Eucalyptus camaldulensis. Yeast two-hybrid (Y2H) and BiFC assay results showed that EcaICE1 can interact with EcaHOS1 protein in the nucleus, and further Y2H assay demonstrated that the 126-185 amino acid region at the N-terminus of EcaICE1 protein was indispensable for its interaction with EcaHOS1 protein. Moreover, we found that the amino acids at positions 143, 145, 158 and 184 within the key interaction region were the potential phosphorylation sites of EcaICE1 based on bioinformatics analysis, and that only the substitution of Serine (Ser) 158 by Alanine (Ala) blocked the protein-protein interactions between EcaICE1 and EcaHOS1 by Y2H and β-galactosidase assays using site-direct mutagenesis. In summary, we first reported that EcaICE1 could interact with EcaHOS1 protein in Eucalyptus, and identified Ser 158 of EcaICE1 as the key phosphorylation site for its interaction with EcaHOS1 protein.

scholarly journals In-depth and 3-Dimensional Exploration of the Budding Yeast Phosphoproteome

2019 ◽  
Author(s):  
Michael Charles Lanz ◽  
Kumar Yugandhar ◽  
Shagun Gupta ◽  
Ethan Sanford ◽  
Vitor Faça ◽  
...  
Keyword(s):  
Protein Interactions ◽  
Cell Biology ◽  
Budding Yeast ◽  
Protein Structures ◽  
Phosphorylation Site ◽  
Eukaryotic Cell ◽  
Phosphorylation Sites ◽  
Protein Protein Interactions ◽  
3 Dimensional ◽  
Regulate Protein

AbstractPhosphorylation is one of the most dynamic and widespread post-translational modifications regulating virtually every aspect of eukaryotic cell biology. Here we present a comprehensive phosphoproteomic dataset for budding yeast, comprised of over 30,000 high confidence phosphorylation sites identified by mass spectrometry. This single dataset nearly doubles the size of the known phosphoproteome in budding yeast and defines a set of cell cycle-regulated phosphorylation events. With the goal of enhancing the identification of functional phosphorylation events, we performed computational positioning of phosphorylation sites on available 3D protein structures and systematically identified events predicted to regulate protein complex architecture. Results reveal a large number of phosphorylation sites mapping to or near protein interaction interfaces, many of which result in steric or electrostatic “clashes” predicted to disrupt the interaction. Phosphorylation site mutants experimentally validate our predictions and support a role for phosphorylation in negatively regulating protein-protein interactions. With the advancement of Cryo-EM and the increasing number of available structures, our approach should help drive the functional and spatial exploration of the phosphoproteome.

Mapping of Protein-Protein Interactions: Web-Based Resources for Revealing Interactomes

2019 ◽  
Vol 26 (21) ◽  
pp. 3890-3910 ◽  
Author(s):  
Branislava Gemovic ◽  
Neven Sumonja ◽  
Radoslav Davidovic ◽  
Vladimir Perovic ◽  
Nevena Veljkovic
Keyword(s):  
Drug Discovery ◽  
Protein Interactions ◽  
Protein Complexes ◽  
Experimental Studies ◽  
Protein Protein Interactions ◽  
Web Based ◽  
Prediction Tools ◽  
Physiological Processes ◽  
Modern Drug ◽  
Ppi Prediction

Background: The significant number of protein-protein interactions (PPIs) discovered by harnessing concomitant advances in the fields of sequencing, crystallography, spectrometry and two-hybrid screening suggests astonishing prospects for remodelling drug discovery. The PPI space which includes up to 650 000 entities is a remarkable reservoir of potential therapeutic targets for every human disease. In order to allow modern drug discovery programs to leverage this, we should be able to discern complete PPI maps associated with a specific disorder and corresponding normal physiology. Objective: Here, we will review community available computational programs for predicting PPIs and web-based resources for storing experimentally annotated interactions. Methods: We compared the capacities of prediction tools: iLoops, Struck2Net, HOMCOS, COTH, PrePPI, InterPreTS and PRISM to predict recently discovered protein interactions. Results: We described sequence-based and structure-based PPI prediction tools and addressed their peculiarities. Additionally, since the usefulness of prediction algorithms critically depends on the quality and quantity of the experimental data they are built on; we extensively discussed community resources for protein interactions. We focused on the active and recently updated primary and secondary PPI databases, repositories specialized to the subject or species, as well as databases that include both experimental and predicted PPIs. Conclusion: PPI complexes are the basis of important physiological processes and therefore, possible targets for cell-penetrating ligands. Reliable computational PPI predictions can speed up new target discoveries through prioritization of therapeutically relevant protein–protein complexes for experimental studies.

Dependence of KCC2 K-Cl cotransporter activity on a conserved carboxy terminus tyrosine residue

2000 ◽  
Vol 279 (3) ◽  
pp. C860-C867 ◽  
Author(s):  
Kevin Strange ◽  
Thomas D. Singer ◽  
Rebecca Morrison ◽  
Eric Delpire
Keyword(s):  
Protein Interactions ◽  
Regulatory Protein ◽  
Phosphorylation Site ◽  
Fold Increase ◽  
Tyrosine Residue ◽  
Carboxy Terminus ◽  
Protein Protein Interactions ◽  
Pharmacological Studies ◽  
Osmotic Homeostasis ◽  
Tyrosine Phosphorylation Site

K-Cl cotransporters (KCC) play fundamental roles in ionic and osmotic homeostasis. To date, four mammalian KCC genes have been identified. KCC2 is expressed exclusively in neurons. Injection of Xenopus oocytes with KCC2 cRNA induced a 20-fold increase in Cl−-dependent, furosemide-sensitive K+ uptake. Oocyte swelling increased KCC2 activity 2–3 fold. A canonical tyrosine phosphorylation site is located in the carboxy termini of KCC2 (R1081–Y1087) and KCC4, but not in other KCC isoforms. Pharmacological studies, however, revealed no regulatory role for phosphorylation of KCC2 tyrosine residues. Replacement of Y1087 with aspartate or arginine dramatically reduced K+ uptake under isotonic and hypotonic conditions. Normal or near-normal cotransporter activity was observed when Y1087 was mutated to phenylalanine, alanine, or isoleucine. A tyrosine residue equivalent to Y1087 is conserved in all identified KCCs from nematodes to humans. Mutation of the Y1087 congener in KCC1 to aspartate also dramatically inhibited cotransporter activity. Taken together, these results suggest that replacement of Y1087 and its congeners with charged residues disrupts the conformational state of the carboxy terminus. We postulate that the carboxy terminus plays an essential role in maintaining the functional conformation of KCC cotransporters and/or is involved in essential regulatory protein-protein interactions.

Functional nonsynonymous single nucleotide polymorphisms from the TGF-β protein interaction network

2007 ◽  
Vol 29 (2) ◽  
pp. 109-117 ◽  
Author(s):  
Sevtap Savas ◽  
Ian W. Taylor ◽  
Jeff L. Wrana ◽  
Hilmi Ozcelik
Keyword(s):  
Single Nucleotide Polymorphisms ◽  
Protein Interactions ◽  
Transforming Growth Factor ◽  
Conservation Status ◽  
Genetic Variations ◽  
Phosphorylation Sites ◽  
Nucleotide Polymorphisms ◽  
Protein Protein Interactions ◽  
Single Nucleotide ◽  
Putative Protein

Protein complexes mediated by protein-protein interactions are essential for many cellular functions. Transforming growth factor (TGF)-β signaling involves a cascade of protein-protein interactions and malfunctioning of this pathway has been implicated in human diseases. Using an in silico approach, we analyzed the naturally occurring human genetic variations from the proteins involved in the TGF-β signaling (10 TGF-β proteins and 242 other proteins interacting with them) to identify the ones that have potential biological consequences. All proteins were searched in the dbSNP database for the presence of nonsynonymous single nucleotide polymorphisms (nsSNPs). A total of 118 validated nsSNPs from 63 proteins were retrieved and analyzed in terms of 1) evolutionary conservation status, 2) being located in a functional protein domain or motif, and 3) altering putative protein motif or phosphorylation sites. Our results indicated the presence of 31 nsSNPs that occurred at evolutionarily conserved residues, 37 nsSNPs were located in protein domains, motifs, or repeats, and 46 nsSNPs were predicted to either create or abolish putative protein motifs or phosphorylation sites. We undertook this study to analyze the human genetic variations that can affect the protein function and the TGF-β signaling. The nsSNPs reported in here can be characterized by experimental approaches to elucidate their exact biological roles and whether they are related to human disease.

scholarly journals A proline-rich sequence unique to MEK1 and MEK2 is required for raf binding and regulates MEK function.

1995 ◽  
Vol 15 (10) ◽  
pp. 5214-5225 ◽  
Author(s):  
A D Catling ◽  
H J Schaeffer ◽  
C W Reuter ◽  
G R Reddy ◽  
M J Weber
Keyword(s):  
Protein Interactions ◽  
Critical Role ◽  
Phosphorylation Site ◽  
Specific Protein ◽  
Protein Protein Interactions ◽  
Serum Stimulation ◽  
And Function

Mammalian MEK1 and MEK2 contain a proline-rich (PR) sequence that is absent both from the yeast homologs Ste7 and Byr1 and from a recently cloned activator of the JNK/stress-activated protein kinases, SEK1/MKK4. Since this PR sequence occurs in MEKs that are regulated by Raf family enzymes but is missing from MEKs and SEKs activated independently of Raf, we sought to investigate the role of this sequence in MEK1 and MEK2 regulation and function. Deletion of the PR sequence from MEK1 blocked the ability of MEK1 to associate with members of the Raf family and markedly attenuated activation of the protein in vivo following growth factor stimulation. In addition, this sequence was necessary for efficient activation of MEK1 in vitro by B-Raf but dispensable for activation by a novel MEK1 activator which we have previously detected in fractionated fibroblast extracts. Furthermore, we found that a phosphorylation site within the PR sequence of MEK1 was required for sustained MEK1 activity in response to serum stimulation of quiescent fibroblasts. Consistent with this observation, we observed that MEK2, which lacks a phosphorylation site at the corresponding position, was activated only transiently following serum stimulation. Finally, we found that deletion of the PR sequence from a constitutively activated MEK1 mutant rendered the protein nontransforming in Rat1 fibroblasts. These observations indicate a critical role for the PR sequence in directing specific protein-protein interactions important for the activation, inactivation, and downstream functioning of the MEKs.

scholarly journals Systematic auditing is essential to debiasing machine learning in biology

2020 ◽  
Author(s):  
Fatma-Elzahraa Eid ◽  
Haitham Elmarakeby ◽  
Yujia Alina Chan ◽  
Nadine Fornelos Martins ◽  
Mahmoud ElHefnawi ◽  
...  
Keyword(s):  
Machine Learning ◽  
Protein Interactions ◽  
Drug Target ◽  
Peptide Binding ◽  
Life Sciences ◽  
Prediction Performance ◽  
Biological Data ◽  
Training Data ◽  
Protein Protein Interactions ◽  
Interest Prediction

AbstractRepresentational biases that are common in biological data can inflate prediction performance and confound our understanding of how and what machine learning (ML) models learn from large complicated datasets. However, auditing for these biases is not a common practice in ML in the life sciences. Here, we devise a systematic auditing framework and harness it to audit three different ML applications of significant therapeutic interest: prediction frameworks of protein-protein interactions, drug-target bioactivity, and MHC-peptide binding. Through this, we identify unrecognized biases that hinder the ML process and result in low model generalizability. Ultimately, we show that, when there is insufficient signal in the training data, ML models are likely to learn primarily from representational biases.

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