scholarly journals Structure and Pathology of Tau Protein in Alzheimer Disease

2012 ◽  
Vol 2012 ◽  
pp. 1-13 ◽  
Author(s):  
Michala Kolarova ◽  
Francisco García-Sierra ◽  
Ales Bartos ◽  
Jan Ricny ◽  
Daniela Ripova
Keyword(s):  
Tau Protein ◽  
Posttranslational Modifications ◽  
Molecular Mechanisms ◽  
Human Life ◽  
Normal Structure ◽  
Proper Function ◽  
Global Trend ◽  
Clinicopathological Significance ◽  
And Function ◽  
Tau Aggregation

Alzheimer's disease (AD) is the most common type of dementia. In connection with the global trend of prolonging human life and the increasing number of elderly in the population, the AD becomes one of the most serious health and socioeconomic problems of the present. Tau protein promotes assembly and stabilizes microtubules, which contributes to the proper function of neuron. Alterations in the amount or the structure of tau protein can affect its role as a stabilizer of microtubules as well as some of the processes in which it is implicated. The molecular mechanisms governing tau aggregation are mainly represented by several posttranslational modifications that alter its structure and conformational state. Hence, abnormal phosphorylation and truncation of tau protein have gained attention as key mechanisms that become tau protein in a pathological entity. Evidences about the clinicopathological significance of phosphorylated and truncated tau have been documented during the progression of AD as well as their capacity to exert cytotoxicity when expressed in cell and animal models. This paper describes the normal structure and function of tau protein and its major alterations during its pathological aggregation in AD.

scholarly journals Snails In Silico: A Review of Computational Studies on the Conopeptides

Marine Drugs ◽  
2019 ◽  
Vol 17 (3) ◽  
pp. 145 ◽  
Author(s):  
Rachael Mansbach ◽  
Timothy Travers ◽  
Benjamin McMahon ◽  
Jeanne Fair ◽  
S. Gnanakaran
Keyword(s):  
Posttranslational Modifications ◽  
High Throughput Screening ◽  
Molecular Mechanisms ◽  
Defense Mechanism ◽  
Docking Studies ◽  
Chemical Diversity ◽  
Machine Learning Techniques ◽  
Peptide Toxins ◽  
Dynamics Simulations ◽  
And Function

Marine cone snails are carnivorous gastropods that use peptide toxins called conopeptides both as a defense mechanism and as a means to immobilize and kill their prey. These peptide toxins exhibit a large chemical diversity that enables exquisite specificity and potency for target receptor proteins. This diversity arises in terms of variations both in amino acid sequence and length, and in posttranslational modifications, particularly the formation of multiple disulfide linkages. Most of the functionally characterized conopeptides target ion channels of animal nervous systems, which has led to research on their therapeutic applications. Many facets of the underlying molecular mechanisms responsible for the specificity and virulence of conopeptides, however, remain poorly understood. In this review, we will explore the chemical diversity of conopeptides from a computational perspective. First, we discuss current approaches used for classifying conopeptides. Next, we review different computational strategies that have been applied to understanding and predicting their structure and function, from machine learning techniques for predictive classification to docking studies and molecular dynamics simulations for molecular-level understanding. We then review recent novel computational approaches for rapid high-throughput screening and chemical design of conopeptides for particular applications. We close with an assessment of the state of the field, emphasizing important questions for future lines of inquiry.

scholarly journals Pharmacological Modulators of Tau Aggregation and Spreading

2020 ◽  
Vol 10 (11) ◽  
pp. 858
Author(s):  
Antonio Dominguez-Meijide ◽  
Eftychia Vasili ◽  
Tiago Fleming Outeiro
Keyword(s):  
Tau Protein ◽  
Neurodegenerative Disorders ◽  
Molecular Mechanisms ◽  
Mechanisms Of Action ◽  
Tau Aggregation ◽  
The Brain ◽  
Pharmacological Modulators

Tauopathies are neurodegenerative disorders characterized by the deposition of aggregates composed of abnormal tau protein in the brain. Additionally, misfolded forms of tau can propagate from cell to cell and throughout the brain. This process is thought to lead to the templated misfolding of the native forms of tau, and thereby, to the formation of newer toxic aggregates, thereby propagating the disease. Therefore, modulation of the processes that lead to tau aggregation and spreading is of utmost importance in the fight against tauopathies. In recent years, several molecules have been developed for the modulation of tau aggregation and spreading. In this review, we discuss the processes of tau aggregation and spreading and highlight selected chemicals developed for the modulation of these processes, their usefulness, and putative mechanisms of action. Ultimately, a stronger understanding of the molecular mechanisms involved, and the properties of the substances developed to modulate them, will lead to the development of safer and better strategies for the treatment of tauopathies.

scholarly journals The role of micro-RNAs in the female reproductive tract

Reproduction ◽  
2012 ◽  
Vol 143 (5) ◽  
pp. 559-576 ◽  
Author(s):  
Warren B Nothnick
Keyword(s):  
Posttranslational Modifications ◽  
Reproductive Tract ◽  
Current Knowledge ◽  
Female Reproductive Tract ◽  
Micro Rna ◽  
Proper Function ◽  
Posttranscriptional Gene Regulation ◽  
Micro Rnas ◽  
And Function

Proper development and function of the female reproductive tract are essential for successful reproduction. Regulation of the differentiated functions of the organs that make up the female reproductive tract is well established to occur at multiple levels including transcription, translation, and posttranslational modifications. Micro-RNA (miRNA)-mediated posttranscriptional gene regulation has emerged as a fundamental mechanism controlling normal tissue development and function. Emerging evidence indicates that miRNAs are expressed within the organs of the female reproductive tract where they function to regulate cellular pathways necessary for proper function of these organs. In this review, the functional significance of miRNAs in the development and function of the organs of the female reproductive tract is discussed. Initial discussion focuses on the role of miRNAs in the development of the organs of the female reproductive tract highlighting recent studies that clearly demonstrate that mice with disrupted Dicer1 expression are sterile, fail to develop uterine glands, and have muted estrogen responsiveness. Next, emphasis moves to discussion on our current knowledge on the characterization of miRNA expression in each of the organs of the female reproductive tract. When possible, information is presented and discussed with respect to regulation, function, and/or functional targets of these miRNA within each specific organ of the female reproductive tract.

scholarly journals Non-Canonical Roles of Tau and Their Contribution to Synaptic Dysfunction

2021 ◽  
Vol 22 (18) ◽  
pp. 10145
Author(s):  
Giacomo Siano ◽  
Chiara Falcicchia ◽  
Nicola Origlia ◽  
Antonino Cattaneo ◽  
Cristina Di Primio
Keyword(s):  
Tau Protein ◽  
Neurodegenerative Disorders ◽  
Neuronal Degeneration ◽  
Synaptic Dysfunction ◽  
Cell Soma ◽  
Post Translational Modifications ◽  
Synaptic Homeostasis ◽  
Wide Range ◽  
And Function ◽  
Tau Aggregation

Tau plays a central role in a group of neurodegenerative disorders collectively named tauopathies. Despite the wide range of diverse symptoms at the onset and during the progression of the pathology, all tauopathies share two common hallmarks, namely the misfolding and aggregation of Tau protein and progressive synaptic dysfunctions. Tau aggregation correlates with cognitive decline and behavioural impairment. The mechanistic link between Tau misfolding and the synaptic dysfunction is still unknown, but this correlation is well established in the human brain and also in tauopathy mouse models. At the onset of the pathology, Tau undergoes post-translational modifications (PTMs) inducing the detachment from the cytoskeleton and its release in the cytoplasm as a soluble monomer. In this condition, the physiological enrichment in the axon is definitely disrupted, resulting in Tau relocalization in the cell soma and in dendrites. Subsequently, Tau aggregates into toxic oligomers and amyloidogenic forms that disrupt synaptic homeostasis and function, resulting in neuronal degeneration. The involvement of Tau in synaptic transmission alteration in tauopathies has been extensively reviewed. Here, we will focus on non-canonical Tau functions mediating synapse dysfunction.

scholarly journals The chromosomal passenger complex: guiding Aurora-B through mitosis

2006 ◽  
Vol 173 (6) ◽  
pp. 833-837 ◽  
Author(s):  
Gerben Vader ◽  
René H. Medema ◽  
Susanne M.A. Lens
Keyword(s):  
Cell Division ◽  
Histone Modification ◽  
Posttranslational Modifications ◽  
Molecular Mechanisms ◽  
Aurora B ◽  
Chromosomal Passenger Complex ◽  
Precise Control ◽  
Chromosome Alignment ◽  
Chromosomal Passenger ◽  
And Function

During mitosis, the chromosomal passenger complex (CPC) orchestrates highly different processes, such as chromosome alignment, histone modification, and cytokinesis. Proper and timely localization of this complex is the key to precise control over the enzymatic core of the CPC, the Aurora-B kinase. We discuss the molecular mechanisms by which the CPC members direct the dynamic localization of the complex throughout cell division. Also, we summarize posttranslational modifications that occur on the CPC and discuss their roles in regulating localization and function of this mitotic complex.

scholarly journals Humanized H19/Igf2 locus reveals diverged imprinting mechanism between mouse and human and reflects Silver–Russell syndrome phenotypes

2016 ◽  
Vol 113 (39) ◽  
pp. 10938-10943 ◽  
Author(s):  
Stella K. Hur ◽  
Andrea Freschi ◽  
Folami Ideraabdullah ◽  
Joanne L. Thorvaldsen ◽  
Lacey J. Luense ◽  
...  
Keyword(s):  
Genomic Imprinting ◽  
Posttranslational Modifications ◽  
Molecular Mechanisms ◽  
Germ Line ◽  
Regulatory Elements ◽  
Allele Specific ◽  
Species Specific ◽  
And Function ◽  
Maternal Imprinting ◽  
Silver Russell Syndrome

Genomic imprinting affects a subset of genes in mammals, such that they are expressed in a monoallelic, parent-of-origin–specific manner. These genes are regulated by imprinting control regions (ICRs), cis-regulatory elements that exhibit allele-specific differential DNA methylation. Although genomic imprinting is conserved in mammals, ICRs are genetically divergent across species. This raises the fundamental question of whether the ICR plays a species-specific role in regulating imprinting at a given locus. We addressed this question at the H19/insulin-like growth factor 2 (Igf2) imprinted locus, the misregulation of which is associated with the human imprinting disorders Beckwith–Wiedemann syndrome (BWS) and Silver–Russell syndrome (SRS). We generated a knock-in mouse in which the endogenous H19/Igf2 ICR (mIC1) is replaced by the orthologous human ICR (hIC1) sequence, designated H19hIC1. We show that hIC1 can functionally replace mIC1 on the maternal allele. In contrast, paternally transmitted hIC1 leads to growth restriction, abnormal hIC1 methylation, and loss of H19 and Igf2 imprinted expression. Imprint establishment at hIC1 is impaired in the male germ line, which is associated with an abnormal composition of histone posttranslational modifications compared with mIC1. Overall, this study reveals evolutionarily divergent paternal imprinting at IC1 between mice and humans. The conserved maternal imprinting mechanism and function at IC1 demonstrates the possibility of modeling maternal transmission of hIC1 mutations associated with BWS in mice. In addition, we propose that further analyses in the paternal knock-in H19+/hIC1 mice will elucidate the molecular mechanisms that may underlie SRS.

scholarly journals Posttranslational Modifications in PD-L1 Turnover and Function: From Cradle to Grave

Biomedicines ◽  
2021 ◽  
Vol 9 (11) ◽  
pp. 1702
Author(s):  
Xinfang Yu ◽  
Wei Li ◽  
Ken H. Young ◽  
Yong Li
Keyword(s):  
Clinical Response ◽  
Cancer Cells ◽  
Posttranslational Modifications ◽  
Molecular Mechanisms ◽  
Clinical Response Rate ◽  
L1 Stability ◽  
Programmed Death ◽  
Programmed Death 1 ◽  
And Function ◽  
L1 Protein

Programmed death-ligand 1 (PD-L1) is one of the most classic immune checkpoint molecules. Cancer cells express PD-L1 to inhibit the activity of effector T cells’ cytotoxicity through programmed death 1 (PD-1) engagement in exposure to inflammatory cytokines. PD-L1 expression levels on cancer cells might affect the clinical response to anti-PD-1/PD-L1 therapies. Hence, understanding molecular mechanisms for regulating PD-L1 expression is essential for improving the clinical response rate and efficacy of PD-1/PD-L1 blockade. Posttranslational modifications (PTMs), including phosphorylation, glycosylation, ubiquitination, and acetylation, regulate PD-L1 stability, cellular translocation, and interaction with its receptor. A coordinated positive and negative regulation via PTMs is required to ensure the balance and function of the PD-L1 protein. In this review, we primarily focus on the roles of PTMs in PD-L1 expression, trafficking, and antitumor immune response. We also discuss the implication of PTMs in anti-PD-1/PD-L1 therapies.

Kedudukan dan Fungsi Bahasa dalam Permuseuman

Metahumaniora ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 54
Author(s):  
Erlina Zulkifli Mahmud ◽  
Taufik Ampera ◽  
Yuyu Yohana Risagarniwa ◽  
Inu Isnaeni Sidiq
Keyword(s):  
Human Life ◽  
Field Research ◽  
Communicative Function ◽  
Language Functions ◽  
The Past ◽  
Library Research ◽  
History Of ◽  
And Function ◽  
Museum Guides ◽  
Bahasa Indonesia

Kedudukan dan fungsi bahasa sebagai alat komunikasi manusia mencakup seluruh bidang kehidupan termasuk ilmu pengetahuan antara lain terkait sejarah peradaban manusia; bagaimana manusia mempertahankan hidupnya, bagaimana manusia memperlakukan alam, bagaimana alam menyediakan segala kebutuhan manusia. Apa yang dilakukan manusia saat ini, saat lampau, dan apa yang dilakukan manusia jauh di masa prasejarah, bagaimana kondisi alam di masa-masa tersebut, apa perubahan dan perkembangannya, dapat didokumentasikan melalui bahasa, divisualisasikan kembali, lalu dipajang sebagai salah satu upaya konversai dan preservasi dalam satu institusi yang disebut museum. Penelitian ini membahas kedudukan dan fungsi bahasa dalam permuseuman. Bagaimana kedudukan dan fungsi bahasa dalam permuseuman baik dalam informasi yang disampaikan oleh pemandu wisata museumnya maupun yang terpajang menyertai benda-benda dan gambar-gambar merupakan tujuan dari penelitian ini. Metode penelitian yang digunakan adalah gabungan antara metode lapangan dan metode literatur. Hasil penelitian menunjukkan bahwa secara umum kedudukan bahasa Indonesia berada pada urutan pertama setelah Bahasa Inggris dan keberadaan kedua bahasa dalam permuseuman ini melibatkan dua fungsi utama bahasa, yakni fungsi komunikatif dan fungsi informatif.The existence and function of language  as a medium of communication covers all fields of human life including knowledge, one of them is the history of human civilization; how humans survived, how human utilized nature for their lives, and how nature provides all the necessities for humans. What humans have been doing now, what they have done in the past and far before that in the pre-history time, how the conditions of the nature at those times were and what changes as well as progresses occurred are documented using language, then re-visualized,  displayed as one of conservation and preservation acts in an institution called museum. This research discusess the existence and function of language in museums. How important the existence of a language in museums and what language functions used in museums both in informations given by the museum guides and on the displays accompanying objects and pictures are the aims of this research. The methods used are the combination between field research and library research. The results show that generally the existence of Indonesian language plays more important role than English and both languages have two main functions; communicative function and informative function.     

A Mucin-Specific Protease Enables Molecular and Functional Analysis of Human Cancer-Associated Mucins

2018 ◽  
Author(s):  
Stacy A. Malaker ◽  
Kayvon Pedram ◽  
Michael J. Ferracane ◽  
Elliot C. Woods ◽  
Jessica Kramer ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Molecular Mechanisms ◽  
Cultured Cells ◽  
High Resolution Mass Spectrometry ◽  
Human Cancer ◽  
Glycosylation Sites ◽  
Bacterial Protease ◽  
Specific Protease ◽  
To Come ◽  
And Function

<div> <div> <div> <p>Mucins are a class of highly O-glycosylated proteins that are ubiquitously expressed on cellular surfaces and are important for human health, especially in the context of carcinomas. However, the molecular mechanisms by which aberrant mucin structures lead to tumor progression and immune evasion have been slow to come to light, in part because methods for selective mucin degradation are lacking. Here we employ high resolution mass spectrometry, polymer synthesis, and computational peptide docking to demonstrate that a bacterial protease, called StcE, cleaves mucin domains by recognizing a discrete peptide-, glycan-, and secondary structure- based motif. We exploited StcE’s unique properties to map glycosylation sites and structures of purified and recombinant human mucins by mass spectrometry. As well, we found that StcE will digest cancer-associated mucins from cultured cells and from ovarian cancer patient-derived ascites fluid. Finally, using StcE we discovered that Siglec-7, a glyco-immune checkpoint receptor, specifically binds sialomucins as biological ligands, whereas the related Siglec-9 receptor does not. Mucin-specific proteolysis, as exemplified by StcE, is therefore a powerful tool for the study of glycoprotein structure and function and for deorphanizing mucin-binding receptors. </p> </div> </div> </div>

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