Lysine methylation is an endogenous post-translational modification of tau protein in human brain and a modulator of aggregation propensity

AbstractGoat milk is a source of nutrition in difficult areas and has lesser allerginicity than cow milk. It is leading in the area for nutraceutical formulation and drug development using goat mammary gland as a bioreactor. Post translational modifications of a protein regulate protein function, biological activity, stabilization and interactions. The protein variants of goat milk from 10 breeds were studied for the post translational modifications by combining highly sensitive 2DE and Q-Exactive LC-MS/MS. Here we observed high levels of post translational modifications in 201 peptides of 120 goat milk proteins. The phosphosites observed for CSN2, CSN1S1, CSN1S2, CSN3 were 11P, 13P, 17P and 6P, respectively in 105 casein phosphopeptides. Whey proteins BLG and LALBA showed 19 and 4 phosphosites respectively. Post translational modification was observed in 45 low abundant non-casein milk proteins mainly associated with signal transduction, immune system, developmental biology and metabolism pathways. Pasp is reported for the first time in 47 sites. The rare conserved peptide sequence of (SSSEE) was observed in αS1 and αS2 casein. The functional roles of identified phosphopeptides included anti-microbial, DPP-IV inhibitory, anti-inflammatory and ACE inhibitory. This is first report from tropics, investigating post translational modifications in casein and non-casein goat milk proteins and studies their interactions.

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iProteinDB: an integrative database of Drosophila post-translational modifications

10.1101/386268 ◽

2018 ◽

Cited By ~ 2

Author(s):

Yanhui Hu ◽

Richelle Sopko ◽

Verena Chung ◽

Romain A. Studer ◽

Sean D. Landry ◽

...

Keyword(s):

Protein Interactions ◽

Protein Function ◽

Large Scale ◽

Model Organisms ◽

General Strategy ◽

Post Translational Modification ◽

Post Translational Modifications ◽

Functional Sites ◽

Evolutionarily Conserved ◽

And Function

AbstractPost-translational modification (PTM) serves as a regulatory mechanism for protein function, influencing stability, protein interactions, activity and localization, and is critical in many signaling pathways. The best characterized PTM is phosphorylation, whereby a phosphate is added to an acceptor residue, commonly serine, threonine and tyrosine. As proteins are often phosphorylated at multiple sites, identifying those sites that are important for function is a challenging problem. Considering that many phosphorylation sites may be non-functional, prioritizing evolutionarily conserved phosphosites provides a general strategy to identify the putative functional sites with regards to regulation and function. To facilitate the identification of conserved phosphosites, we generated a large-scale phosphoproteomics dataset from Drosophila embryos collected from six closely-related species. We built iProteinDB (https://www.flyrnai.org/tools/iproteindb/), a resource integrating these data with other high-throughput PTM datasets, including vertebrates, and manually curated information for Drosophila. At iProteinDB, scientists can view the PTM landscape for any Drosophila protein and identify predicted functional phosphosites based on a comparative analysis of data from closely-related Drosophila species. Further, iProteinDB enables comparison of PTM data from Drosophila to that of orthologous proteins from other model organisms, including human, mouse, rat, Xenopus laevis, Danio rerio, and Caenorhabditis elegans.

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Protein lysine 43 methylation by EZH1 promotes AML1-ETO transcriptional repression in leukemia

Nature Communications ◽

10.1038/s41467-019-12960-6 ◽

2019 ◽

Vol 10 (1) ◽

Cited By ~ 1

Author(s):

Liping Dou ◽

Fei Yan ◽

Jiuxia Pang ◽

Dehua Zheng ◽

Dandan Li ◽

...

Keyword(s):

Dna Sequences ◽

Transcriptional Repression ◽

Lysine Methylation ◽

Post Translational Modification ◽

Histone Lysine Methylation ◽

Histone Lysine ◽

Histone Lysine Methyltransferase ◽

Lysine Methyltransferase

Abstract The oncogenic fusion protein AML1-ETO retains the ability of AML1 to interact with the enhancer core DNA sequences, but blocks AML1-dependent transcription. Previous studies have shown that post-translational modification of AML1-ETO may play a role in its regulation. Here we report that AML1-ETO-positive patients, with high histone lysine methyltransferase Enhancer of zeste homolog 1 (EZH1) expression, show a worse overall survival than those with lower EZH1 expression. EZH1 knockdown impairs survival and proliferation of AML1-ETO-expressing cells in vitro and in vivo. We find that EZH1 WD domain binds to the AML1-ETO NHR1 domain and methylates AML1-ETO at lysine 43 (Lys43). This requires the EZH1 SET domain, which augments AML1-ETO-dependent repression of tumor suppressor genes. Loss of Lys43 methylation by point mutation or domain deletion impairs AML1-ETO-repressive activity. These findings highlight the role of EZH1 in non-histone lysine methylation, indicating that cooperation between AML1-ETO and EZH1 and AML1-ETO site-specific lysine methylation promote AML1-ETO transcriptional repression in leukemia.

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Dextran sulphate-induced tau assemblies cause endogenous tau aggregation and propagation in wild-type mice

Brain Communications ◽

10.1093/braincomms/fcaa091 ◽

2020 ◽

Vol 2 (2) ◽

Author(s):

Masami Masuda-Suzukake ◽

Genjiro Suzuki ◽

Masato Hosokawa ◽

Takashi Nonaka ◽

Michel Goedert ◽

...

Keyword(s):

Transgenic Mice ◽

Tau Protein ◽

Guanidine Hydrochloride ◽

Intracerebral Injection ◽

Dextran Sulphate ◽

Wild Type ◽

Synthetic Filament ◽

Biochemical Analyses ◽

Tau Aggregation

Abstract Accumulation of assembled tau protein in the central nervous system is characteristic of Alzheimer’s disease and several other neurodegenerative diseases, called tauopathies. Recent studies have revealed that propagation of assembled tau is key to understanding the pathological mechanisms of these diseases. Mouse models of tau propagation are established by injecting human-derived tau seeds intracerebrally; nevertheless, these have a limitation in terms of regulation of availability. To date, no study has shown that synthetic assembled tau induce tau propagation in non-transgenic mice. Here we confirm that dextran sulphate, a sulphated glycosaminoglycan, induces the assembly of recombinant tau protein into filaments in vitro. As compared to tau filaments induced by heparin, those induced by dextran sulphate showed higher thioflavin T fluorescence and lower resistance to guanidine hydrochloride, which suggests that the two types of filaments have distinct conformational features. Unlike other synthetic filament seeds, intracerebral injection of dextran sulphate-induced assemblies of recombinant tau caused aggregation of endogenous murine tau in wild-type mice. AT8-positive tau was present at the injection site 1 month after injection, from where it spread to anatomically connected regions. Induced tau assemblies were also stained by anti-tau antibodies AT100, AT180, 12E8, PHF1, anti-pS396 and anti-pS422. They were thioflavin- and Gallyas-Braak silver-positive, indicative of amyloid. In biochemical analyses, accumulated sarkosyl-insoluble and hyperphosphorylated tau was observed in the injected mice. In conclusion, we revealed that intracerebral injection of synthetic full-length wild-type tau seeds prepared in the presence of dextran sulphate caused tau propagation in non-transgenic mice. These findings establish that propagation of tau assemblies does not require tau to be either mutant and/or overexpressed.

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Phosphorylation of the overlooked tyrosine 310 regulates the structure, aggregation, and microtubule- and lipid-binding properties of Tau

Journal of Biological Chemistry ◽

10.1074/jbc.ra119.012517 ◽

2020 ◽

Vol 295 (23) ◽

pp. 7905-7922 ◽

Cited By ~ 4

Author(s):

Nadine Ait-Bouziad ◽

Anass Chiki ◽

Galina Limorenko ◽

Shifeng Xiao ◽

David Eliezer ◽

...

Keyword(s):

Lipid Binding ◽

Binding Properties ◽

Post Translational Modifications ◽

Unique Role ◽

Tyrosine Residues ◽

Normal Functions ◽

Tau Aggregation ◽

Β Sheet

The microtubule-associated protein Tau is implicated in the pathogenesis of several neurodegenerative disorders, including Alzheimer's disease. Increasing evidence suggests that post-translational modifications play critical roles in regulating Tau's normal functions and its pathogenic properties in tauopathies. Very little is known about how phosphorylation of tyrosine residues influences the structure, aggregation, and microtubule- and lipid-binding properties of Tau. Here, we sought to determine the relative contributions of phosphorylation of one or several of the five tyrosine residues in Tau (Tyr-18, -29, -197, -310, and -394) to the regulation of its biophysical, aggregation, and functional properties. We used a combination of site-specific mutagenesis and in vitro phosphorylation by c-Abl kinase to generate Tau species phosphorylated at all five tyrosine residues, all tyrosine residues except Tyr-310 or Tyr-394 (pTau-Y310F and pTau-Y394F, respectively) and Tau phosphorylated only at Tyr-310 or Tyr-394 (4F/pTyr-310 or 4F/pTyr-394). We observed that phosphorylation of all five tyrosine residues, multiple N-terminal tyrosine residues (Tyr-18, -29, and -197), or specific phosphorylation only at residue Tyr-310 abolishes Tau aggregation and inhibits its microtubule- and lipid-binding properties. NMR experiments indicated that these effects are mediated by a local decrease in β-sheet propensity of Tau's PHF6 domain. Our findings underscore Tyr-310 phosphorylation has a unique role in the regulation of Tau aggregation, microtubule, and lipid interactions. These results also highlight the importance of conducting further studies to elucidate the role of Tyr-310 in the regulation of Tau's normal functions and pathogenic properties.

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SET7/9-dependent methylation of ARTD1 at K508 stimulates poly-ADP-ribose formation after oxidative stress

Open Biology ◽

10.1098/rsob.120173 ◽

2013 ◽

Vol 3 (10) ◽

pp. 120173 ◽

Cited By ~ 23

Author(s):

Ingrid Kassner ◽

Anneli Andersson ◽

Monika Fey ◽

Martin Tomas ◽

Elisa Ferrando-May ◽

...

Keyword(s):

Oxidative Stress ◽

Protein Interactions ◽

Protein Function ◽

Dependent Manner ◽

Protein Protein Interactions ◽

Post Translational Modification ◽

Target Proteins ◽

Protein Methyltransferase

ADP-ribosyltransferase diphtheria toxin-like 1 (ARTD1, formerly PARP1) is localized in the nucleus, where it ADP-ribosylates specific target proteins. The post-translational modification (PTM) with a single ADP-ribose unit or with polymeric ADP-ribose (PAR) chains regulates protein function as well as protein–protein interactions and is implicated in many biological processes and diseases. SET7/9 (Setd7, KMT7) is a protein methyltransferase that catalyses lysine monomethylation of histones, but also methylates many non-histone target proteins such as p53 or DNMT1. Here, we identify ARTD1 as a new SET7/9 target protein that is methylated at K508 in vitro and in vivo . ARTD1 auto-modification inhibits its methylation by SET7/9, while auto-poly-ADP-ribosylation is not impaired by prior methylation of ARTD1. Moreover, ARTD1 methylation by SET7/9 enhances the synthesis of PAR upon oxidative stress in vivo . Furthermore, laser irradiation-induced PAR formation and ARTD1 recruitment to sites of DNA damage in a SET7/9-dependent manner. Together, these results reveal a novel mechanism for the regulation of cellular ARTD1 activity by SET7/9 to assure efficient PAR formation upon cellular stress.

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From Aggregation to Inhibition: N-Amination Converts Amyloidogenic Tau Peptides into Soluble Antagonists of Cellular Seeding

10.26434/chemrxiv.14478225 ◽

2021 ◽

Author(s):

Kamlesh Makwana ◽

Matthew P. Sarnowski ◽

Jiyuan Miao ◽

Yu-Shan Lin ◽

Juan Del Valle

Keyword(s):

Small Molecules ◽

Tau Protein ◽

Supramolecular Assembly ◽

Rational Basis ◽

Protein Assemblies ◽

Amino Groups ◽

Minimalist Approach ◽

Full Complement ◽

Tau Aggregation

The spread of neurofibrillary tangles resulting from tau protein aggregation is a hallmark of Alzheimer’s and related neurodegenerative diseases. Early oligomerization of tau involves conformational reorganization into parallel b-sheet structures and supramolecular assembly into toxic fibrils. Despite the need for selective inhibitors of tau propagation, b-rich protein assemblies are inherently difficult to target with small molecules. Here, we describe a minimalist approach to mimic the aggregation-prone modules within tau. We carried out a backbone residue scan and show that amide N-amination completely abolishes the tendency of these peptides to self-aggregate, rendering them soluble mimics of ordered b-strands from the tau R2 and R3 domains. Several N-amino peptides (NAPs) inhibit disease-associated tau aggregation and prevent fibril formation in vitro. We further demonstrate that NAPs 12 and 13 are effective at blocking the cellular seeding of endogenous tau by interacting with both monomeric or fibrillar forms of extracellular tau. Peptidomimetic 12 is serum stable, non-toxic to neuronal cells, and selectivity inhibits the aggregation of tau over Ab42. Structural analysis of our lead NAPs shows considerable conformational constraint imposed by the N-amino groups. The enhanced rigidity and full complement of sidechains thus enables NAPs to recognize tau fibrils. The described backbone N-amination approach provides a rational basis for the mimicry of other aggregation-prone peptides that drive pathogenic protein assembly.

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From Aggregation to Inhibition: N-Amination Converts Amyloidogenic Tau Peptides into Soluble Antagonists of Cellular Seeding

10.26434/chemrxiv.14478225.v1 ◽

2021 ◽

Author(s):

Kamlesh Makwana ◽

Matthew P. Sarnowski ◽

Jiyuan Miao ◽

Yu-Shan Lin ◽

Juan Del Valle

Keyword(s):

Small Molecules ◽

Tau Protein ◽

Supramolecular Assembly ◽

Rational Basis ◽

Protein Assemblies ◽

Amino Groups ◽

Minimalist Approach ◽

Full Complement ◽

Tau Aggregation

The spread of neurofibrillary tangles resulting from tau protein aggregation is a hallmark of Alzheimer’s and related neurodegenerative diseases. Early oligomerization of tau involves conformational reorganization into parallel b-sheet structures and supramolecular assembly into toxic fibrils. Despite the need for selective inhibitors of tau propagation, b-rich protein assemblies are inherently difficult to target with small molecules. Here, we describe a minimalist approach to mimic the aggregation-prone modules within tau. We carried out a backbone residue scan and show that amide N-amination completely abolishes the tendency of these peptides to self-aggregate, rendering them soluble mimics of ordered b-strands from the tau R2 and R3 domains. Several N-amino peptides (NAPs) inhibit disease-associated tau aggregation and prevent fibril formation in vitro. We further demonstrate that NAPs 12 and 13 are effective at blocking the cellular seeding of endogenous tau by interacting with both monomeric or fibrillar forms of extracellular tau. Peptidomimetic 12 is serum stable, non-toxic to neuronal cells, and selectivity inhibits the aggregation of tau over Ab42. Structural analysis of our lead NAPs shows considerable conformational constraint imposed by the N-amino groups. The enhanced rigidity and full complement of sidechains thus enables NAPs to recognize tau fibrils. The described backbone N-amination approach provides a rational basis for the mimicry of other aggregation-prone peptides that drive pathogenic protein assembly.

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Profiling of lysine-acetylated proteins in human urine

10.1101/128207 ◽

2017 ◽

Author(s):

Weiwei Qin ◽

Zhenhuan Du ◽

He Huang ◽

Youhe Gao

Keyword(s):

Human Urine ◽

High Resolution Mass Spectrometry ◽

The Body ◽

Lysine Acetylation ◽

Biological Processes ◽

Post Translational Modification ◽

Post Translational Modifications ◽

Normal Human ◽

Measurable Change

AbstractBiomarker is the measurable change associated with a physiological or pathophysiological process, its nature is change. Contrast to the blood which is under homeostatic controls, urine reflects changes in the body earlier and more sensitive therefore is a better biomarker source. Lysine acetylation is an abundant and highly regulated post-translational modification. It plays a pivotal role in modulating diverse biological processes and is associated with various important diseases. Enrichment or visualization of proteins with specific post-translational modifications provides a method for sampling the urinary proteome and reducing sample complexity. In this study, we used anti-acetyllysine antibody-based immunoaffinity enrichment combined with high-resolution mass spectrometry to profile lysine-acetylated proteins in normal human urine. A total of 629 acetylation sites on 315 proteins were identified, including some very low-abundance proteins. This is the first proteome-wide characterization of lysine acetylation proteins in normal human urine. Our dataset provides a useful resource for the further discovery of the lysine acetylated proteins as biomarker in urine.

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Tau Post-translational Modifications: Dynamic Transformers of Tau Function, Degradation, and Aggregation

Frontiers in Neurology ◽

10.3389/fneur.2020.595532 ◽

2021 ◽

Vol 11 ◽

Author(s):

Carolina Alquezar ◽

Shruti Arya ◽

Aimee W. Kao

Keyword(s):

Protein Interactions ◽

Protein Function ◽

Protein Localization ◽

Critical Role ◽

Protein Protein Interactions ◽

Post Translational Modification ◽

Post Translational Modifications ◽

Tau Function ◽

Potential Impact ◽

Important Position

Post-translational modifications (PTMs) on tau have long been recognized as affecting protein function and contributing to neurodegeneration. The explosion of information on potential and observed PTMs on tau provides an opportunity to better understand these modifications in the context of tau homeostasis, which becomes perturbed with aging and disease. Prevailing views regard tau as a protein that undergoes abnormal phosphorylation prior to its accumulation into the toxic aggregates implicated in Alzheimer's disease (AD) and other tauopathies. However, the phosphorylation of tau may, in fact, represent part of the normal but interrupted function and catabolism of the protein. In addition to phosphorylation, tau undergoes another forms of post-translational modification including (but not limited to), acetylation, ubiquitination, glycation, glycosylation, SUMOylation, methylation, oxidation, and nitration. A holistic appreciation of how these PTMs regulate tau during health and are potentially hijacked in disease remains elusive. Recent studies have reinforced the idea that PTMs play a critical role in tau localization, protein-protein interactions, maintenance of levels, and modifying aggregate structure. These studies also provide tantalizing clues into the possibility that neurons actively choose how tau is post-translationally modified, in potentially competitive and combinatorial ways, to achieve broad, cellular programs commensurate with the distinctive environmental conditions found during development, aging, stress, and disease. Here, we review tau PTMs and describe what is currently known about their functional impacts. In addition, we classify these PTMs from the perspectives of protein localization, electrostatics, and stability, which all contribute to normal tau function and homeostasis. Finally, we assess the potential impact of tau PTMs on tau solubility and aggregation. Tau occupies an undoubtedly important position in the biology of neurodegenerative diseases. This review aims to provide an integrated perspective of how post-translational modifications actively, purposefully, and dynamically remodel tau function, clearance, and aggregation. In doing so, we hope to enable a more comprehensive understanding of tau PTMs that will positively impact future studies.

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