scholarly journals C-terminal tail polyglycylation and polyglutamylation alter microtubule mechanical properties

2019 ◽  
Author(s):  
Kathryn P. Wall ◽  
Harold Hart ◽  
Thomas Lee ◽  
Cynthia Page ◽  
Taviare L. Hawkins ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Molecular Mechanisms ◽  
High Stress ◽  
Resonance Spectroscopy ◽  
Post Translational Modification ◽  
Cellular Functions ◽  
Peptide Backbone ◽  
Post Translational Modifications ◽  
Intrinsic Stiffness ◽  
Insight Into

ABSTRACTMicrotubules are biopolymers that perform diverse cellular functions. The regulation of microtubule behavior occurs in part through post-translational modification of both the α- and β- subunits of tubulin. One class of modifications is the heterogeneous addition of glycine and glutamate residues to the disordered C-terminal tails of tubulin. Due to their prevalence in stable, high stress cellular structures such as cilia, we sought to determine if these modifications alter the intrinsic stiffness of microtubules. Here we describe the purification and characterization of differentially-modified pools of tubulin from Tetrahymena thermophila. We found that glycylation on the α-C-terminal tail is a key determinant of microtubule stiffness, but does not affect the number of protofilaments incorporated into microtubules. We measured the dynamics of the tail peptide backbone using nuclear magnetic resonance spectroscopy. We found that the spin-spin relaxation rate (R2) showed a pronounced decreased as a function of distance from the tubulin surface for the α-tubulin tail, indicating that the α-tubulin tail interacts with the dimer surface. This suggests that the interactions of the α-C-terminal tail with the tubulin body contributes to the stiffness of the assembled microtubule, providing insight into the mechanism by which glycylation and glutamylation can alter microtubule mechanical properties.SIGNIFICANCEMicrotubules are regulated in part by post-translational modifications including the heterogeneous addition of glycine and glutamate residues to the C-terminal tails. By producing and characterizing differentially-modified tubulin, this work provides insight into the molecular mechanisms of how these modifications alter intrinsic microtubule properties such as flexibility. These results have broader implications for mechanisms of how ciliary structures are able to function under high stress.

scholarly journals Molecular Pathways Involved in the Development of Congenital Erythrocytosis

Genes ◽  
2021 ◽  
Vol 12 (8) ◽  
pp. 1150
Author(s):  
Jana Tomc ◽  
Nataša Debeljak
Keyword(s):  
Signal Transduction ◽  
Iron Homeostasis ◽  
Molecular Mechanisms ◽  
Oxygen Affinity ◽  
Molecular Pathways ◽  
Disease Development ◽  
Post Translational Modifications ◽  
Hemoglobin Oxygen Affinity ◽  
Insight Into ◽  
Idiopathic Erythrocytosis

Patients with idiopathic erythrocytosis are directed to targeted genetic testing including nine genes involved in oxygen sensing pathway in kidneys, erythropoietin signal transduction in pre-erythrocytes and hemoglobin-oxygen affinity regulation in mature erythrocytes. However, in more than 60% of cases the genetic cause remains undiagnosed, suggesting that other genes and mechanisms must be involved in the disease development. This review aims to explore additional molecular mechanisms in recognized erythrocytosis pathways and propose new pathways associated with this rare hematological disorder. For this purpose, a comprehensive review of the literature was performed and different in silico tools were used. We identified genes involved in several mechanisms and molecular pathways, including mRNA transcriptional regulation, post-translational modifications, membrane transport, regulation of signal transduction, glucose metabolism and iron homeostasis, which have the potential to influence the main erythrocytosis-associated pathways. We provide valuable theoretical information for deeper insight into possible mechanisms of disease development. This information can be also helpful to improve the current diagnostic solutions for patients with idiopathic erythrocytosis.

scholarly journals Post-translational Modifications are Required for Circadian Clock Regulation in Vertebrates

2019 ◽  
Vol 20 (5) ◽  
pp. 332-339 ◽  
Author(s):  
Yoshimi Okamoto-Uchida ◽  
Junko Izawa ◽  
Akari Nishimura ◽  
Atsuhiko Hattori ◽  
Nobuo Suzuki ◽  
...  
Keyword(s):  
Transcriptional Activity ◽  
Molecular Mechanisms ◽  
Feedback Loops ◽  
Circadian Clocks ◽  
Post Translational Modification ◽  
Post Translational Modifications ◽  
Negative Feedback Loops ◽  
Genetic Techniques ◽  
External Signals ◽  
Exact Timing

Circadian clocks are intrinsic, time-tracking systems that bestow upon organisms a survival advantage. Under natural conditions, organisms are trained to follow a 24-h cycle under environmental time cues such as light to maximize their physiological efficiency. The exact timing of this rhythm is established via cell-autonomous oscillators called cellular clocks, which are controlled by transcription/ translation-based negative feedback loops. Studies using cell-based systems and genetic techniques have identified the molecular mechanisms that establish and maintain cellular clocks. One such mechanism, known as post-translational modification, regulates several aspects of these cellular clock components, including their stability, subcellular localization, transcriptional activity, and interaction with other proteins and signaling pathways. In addition, these mechanisms contribute to the integration of external signals into the cellular clock machinery. Here, we describe the post-translational modifications of cellular clock regulators that regulate circadian clocks in vertebrates.

scholarly journals Convergent and distributed effects of the schizophrenia-associated 3q29 deletion on the human neural transcriptome

2020 ◽  
Author(s):  
Esra Sefik ◽  
Ryan H. Purcell ◽  
Elaine F. Walker ◽  
Gary J. Bassell ◽  
Jennifer G. Mulle ◽  
...  
Keyword(s):  
Molecular Mechanisms ◽  
Single Gene ◽  
Normal Function ◽  
Cellular Functions ◽  
Protein Coding ◽  
Post Translational Modifications ◽  
Increased Risk ◽  
Disease Associations ◽  
Guilt By Association ◽  
The Impact

AbstractThe 3q29 deletion (3q29Del) confers >40-fold increased risk for schizophrenia. However, no single gene in this interval is definitively associated with disease, prompting the hypothesis that neuropsychiatric sequelae emerge upon loss of multiple functionally-connected genes. 3q29 genes are unevenly annotated and the impact of 3q29Del on the human neural transcriptome is unknown. To systematically formulate unbiased hypotheses about molecular mechanisms linking 3q29Del to neuropsychiatric illness, we conducted a systems-level network analysis of the non-pathological adult human cortical transcriptome and generated evidence-based predictions that relate 3q29 genes to novel functions and disease associations. The 21 protein-coding genes located in the interval segregated into seven clusters of highly co-expressed genes, demonstrating both convergent and distributed effects of 3q29Del across the interrogated transcriptomic landscape. Pathway analysis of these clusters indicated involvement in nervous-system functions, including synaptic signaling and organization, as well as core cellular functions, including transcriptional regulation, post-translational modifications, chromatin remodeling and mitochondrial metabolism. Top network-neighbors of 3q29 genes showed significant overlap with known schizophrenia, autism and intellectual disability-risk genes, suggesting that 3q29Del biology is relevant to idiopathic disease. Leveraging “guilt by association”, we propose nine 3q29 genes, including one hub gene, as prioritized drivers of neuropsychiatric risk. These results provide testable hypotheses for experimental analysis on causal drivers and mechanisms of the largest known genetic risk factor for schizophrenia and highlight the study of normal function in non-pathological post-mortem tissue to further our understanding of psychiatric genetics, especially for rare syndromes like 3q29Del, where access to neural tissue from carriers is unavailable or limited.

scholarly journals Angiostatic cues from the matrix: Endothelial cell autophagy meets hyaluronan biology

2020 ◽  
Vol 295 (49) ◽  
pp. 16797-16812
Author(s):  
Carolyn G. Chen ◽  
Renato V. Iozzo
Keyword(s):  
Molecular Mechanisms ◽  
Biological Functions ◽  
Post Translational Modifications ◽  
Binding Partner ◽  
Master Regulators ◽  
The Matrix ◽  
Vascular Endothelia ◽  
Insight Into ◽  
Review Current

The extracellular matrix encompasses a reservoir of bioactive macromolecules that modulates a cornucopia of biological functions. A prominent body of work posits matrix constituents as master regulators of autophagy and angiogenesis and provides molecular insight into how these two processes are coordinated. Here, we review current understanding of the molecular mechanisms underlying hyaluronan and HAS2 regulation and the role of soluble proteoglycan in affecting autophagy and angiogenesis. Specifically, we assess the role of proteoglycan-evoked autophagy in regulating angiogenesis via the HAS2-hyaluronan axis and ATG9A, a novel HAS2 binding partner. We discuss extracellular hyaluronan biology and the post-transcriptional and post-translational modifications that regulate its main synthesizer, HAS2. We highlight the emerging group of proteoglycans that utilize outside-in signaling to modulate autophagy and angiogenesis in cancer microenvironments and thoroughly review the most up-to-date understanding of endorepellin signaling in vascular endothelia, providing insight into the temporal complexities involved.

scholarly journals Reading More than Histones: The Prevalence of Nucleic Acid Binding among Reader Domains

Molecules ◽  
2018 ◽  
Vol 23 (10) ◽  
pp. 2614 ◽  
Author(s):  
Tyler Weaver ◽  
Emma Morrison ◽  
Catherine Musselman
Keyword(s):  
Nucleic Acid ◽  
Molecular Mechanisms ◽  
Binding Activity ◽  
Nucleic Acid Binding ◽  
Post Translational Modification ◽  
Histone Proteins ◽  
Post Translational Modifications ◽  
Histone Binding ◽  
Functional Implications ◽  
Nucleic Acid Binding Activity

The eukaryotic genome is packaged into the cell nucleus in the form of chromatin, a complex of genomic DNA and histone proteins. Chromatin structure regulation is critical for all DNA templated processes and involves, among many things, extensive post-translational modification of the histone proteins. These modifications can be “read out” by histone binding subdomains known as histone reader domains. A large number of reader domains have been identified and found to selectively recognize an array of histone post-translational modifications in order to target, retain, or regulate chromatin-modifying and remodeling complexes at their substrates. Interestingly, an increasing number of these histone reader domains are being identified as also harboring nucleic acid binding activity. In this review, we present a summary of the histone reader domains currently known to bind nucleic acids, with a focus on the molecular mechanisms of binding and the interplay between DNA and histone recognition. Additionally, we highlight the functional implications of nucleic acid binding in chromatin association and regulation. We propose that nucleic acid binding is as functionally important as histone binding, and that a significant portion of the as yet untested reader domains will emerge to have nucleic acid binding capabilities.

H2S signaling in redox regulation of cellular functions

2013 ◽  
Vol 91 (1) ◽  
pp. 8-14 ◽  
Author(s):  
Youngjun Ju ◽  
Weihua Zhang ◽  
Yanxi Pei ◽  
Guangdong Yang
Keyword(s):  
Mammalian Cells ◽  
Redox Regulation ◽  
Molecular Mechanisms ◽  
Current Knowledge ◽  
Redox Homeostasis ◽  
Therapeutic Interventions ◽  
Post Translational Modification ◽  
Cellular Functions ◽  
Future Design ◽  
Cellular Effects

Hydrogen sulfide (H2S) is traditionally recognized as a toxic gas with a rotten-egg smell. In just the last few decades, H2S has been found to be one of a family of gasotransmitters, together with nitric oxide and carbon monoxide, and various physiologic effects of H2S have been reported. Among the most acknowledged molecular mechanisms for the cellular effects of H2S is the regulation of intracellular redox homeostasis and post-translational modification of proteins through S-sulfhydration. On the one side, H2S can promote an antioxidant effect and is cytoprotective; on the other side, H2S stimulates oxidative stress and is cytotoxic. This review summarizes our current knowledge of the antioxidant versus pro-oxidant effects of H2S in mammalian cells and describes the Janus-faced properties of this novel gasotransmitter. The redox regulation for the cellular effects of H2S through S-sulfhydration and the role of H2S in glutathione generation is also recapitulated. A better understanding of H2S-regualted redox homeostasis will pave the way for future design of novel pharmacological and therapeutic interventions for various diseases.

SUMO under stress

2008 ◽  
Vol 36 (5) ◽  
pp. 874-878 ◽  
Author(s):  
Denis Tempé ◽  
Marc Piechaczyk ◽  
Guillaume Bossis
Keyword(s):  
Molecular Mechanisms ◽  
Environmental Stresses ◽  
Present Review ◽  
Post Translational Modification ◽  
Cellular Functions ◽  
And Function

During the last decade, SUMOylation has emerged as a central regulatory post-translational modification in the control of the fate and function of proteins. However, how SUMOylation is regulated itself has just started to be delineated. It appears now that SUMO (small ubiquitin-related modifier) conjugation/deconjugation equilibrium is affected by various environmental stresses, including osmotic, hypoxic, heat, oxidative and genotoxic stresses. This regulation occurs either at the level of individual targets, through an interplay between stress-induced phosphorylation and SUMOylation, or via modulation of the conjugation/deconjugation machinery abundance or activity. The present review gives an overview of the connections between stress and SUMOylation, the underlying molecular mechanisms and their effects on cellular functions.

scholarly journals New Insight into Molecular and Hormonal Connection in Andrology

2021 ◽  
Vol 22 (21) ◽  
pp. 11908
Author(s):  
Davide Francomano ◽  
Valerio Sanguigni ◽  
Paolo Capogrosso ◽  
Federico Deho ◽  
Gabriele Antonini
Keyword(s):  
Sexual Function ◽  
Molecular Mechanisms ◽  
Vascular Wall ◽  
Cell Junction ◽  
Testicular Development ◽  
Cellular Functions ◽  
Inflammatory Site ◽  
Male Sexual Function ◽  
Molecular Patterns ◽  
Insight Into

Hormones and cytokines are known to regulate cellular functions in the testes. These biomolecules induce a broad spectrum of effects on various level of spermatogenesis, and among them is the modulation of cell junction restructuring between Sertoli cells and germ cells in the seminiferous epithelium. Cytokines and androgens are closely related, and both correct testicular development and the maintenance of spermatogenesis depend on their function. Cytokines also play a crucial role in the immune testicular system, activating and directing leucocytes across the endothelial barrier to the inflammatory site, as well as in increasing their adhesion to the vascular wall. The purpose of this review is to revise the most recent findings on molecular mechanisms that play a key role in male sexual function, focusing on three specific molecular patterns, namely, cytokines, miRNAs, and endothelial progenitor cells. Numerous reports on the interactions between the immune and endocrine systems can be found in the literature. However, there is not yet a multi-approach review of the literature underlying the role between molecular patterns and testicular and sexual function.

Protein kinase Cδ and apoptosis

2007 ◽  
Vol 35 (5) ◽  
pp. 1001-1004 ◽  
Author(s):  
M.E. Reyland
Keyword(s):  
Protein Kinase ◽  
Molecular Mechanisms ◽  
Cell Types ◽  
Nuclear Accumulation ◽  
Post Translational Modification ◽  
Cellular Functions ◽  
Caspase Cleavage ◽  
Kinase C ◽  
Pkc Protein Kinase C ◽  
Apoptotic Activity

The PKC (protein kinase C) family regulates diverse cellular functions and specific isoforms have been shown to be critical regulators of cell proliferation and survival. In particular, PKCδ is known to be a critical pro-apoptotic signal in many cell types. Work in our laboratory has focused on understanding the molecular mechanisms through which PKCδ regulates apoptosis and on how the pro-apoptotic activity of this ubiquitous kinase is regulated such that cells only activate the apoptotic cascade when appropriate. We have identified multiple regulatory steps that activate the pro-apoptotic function of PKCδ in response to genotoxins. Our studies show that apoptotic signals induce rapid post-translational modification of PKCδ in the regulatory domain, which facilitates translocation of the kinase from the cytoplasm to the nucleus. Active caspase 3 also accumulates in the nucleus under these conditions, resulting in caspase cleavage of PKCδ and generation of a constitutively activated form of PKCδ [δCF (PKCδ catalytic fragment)]. In contrast with PKCδ, δCF is constitutively present in the nucleus, and this nuclear accumulation of PKCδ is essential for apoptosis. Thus our studies suggest that tight regulation of nuclear import and of PKCδ is critical for cell survival and that caspase cleavage of PKCδ in the nucleus signals an irreversible commitment to apoptosis.

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