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Biochemical Pharmacology Aug 2023Cellular actin dynamic is controlled by a plethora of actin binding proteins (ABPs), including actin nucleating, bundling, cross-linking, capping, and severing proteins.... (Review)
Review
Cellular actin dynamic is controlled by a plethora of actin binding proteins (ABPs), including actin nucleating, bundling, cross-linking, capping, and severing proteins. In this review, regulation of actin dynamics by ABPs will be introduced, and the role of the F-actin severing protein cofilin-1 and the F-actin bundling protein L-plastin in actin dynamics discussed in more detail. Since up-regulation of these proteins in different kinds of cancers is associated with malignant progression of cancer cells, we suggest the cryogenic electron microscopy (Cryo-EM) structure of F- actin with the respective ABP as template for in silico drug design to specifically disrupt the interaction of these ABPs with F-actin.
Topics: Actins; Cryoelectron Microscopy; Microfilament Proteins; Actin Cytoskeleton; Drug Discovery; Protein Binding
PubMed: 37399949
DOI: 10.1016/j.bcp.2023.115680 -
Nature Communications Mar 2024Myelinated axons form long-range connections that enable rapid communication between distant brain regions, but how genetics governs the strength and organization of...
Myelinated axons form long-range connections that enable rapid communication between distant brain regions, but how genetics governs the strength and organization of these connections remains unclear. We perform genome-wide association studies of 206 structural connectivity measures derived from diffusion magnetic resonance imaging tractography of 26,333 UK Biobank participants, each representing the density of myelinated connections within or between a pair of cortical networks, subcortical structures or cortical hemispheres. We identify 30 independent genome-wide significant variants after Bonferroni correction for the number of measures studied (126 variants at nominal genome-wide significance) implicating genes involved in myelination (SEMA3A), neurite elongation and guidance (NUAK1, STRN, DPYSL2, EPHA3, SEMA3A, HGF, SHTN1), neural cell proliferation and differentiation (GMNC, CELF4, HGF), neuronal migration (CCDC88C), cytoskeletal organization (CTTNBP2, MAPT, DAAM1, MYO16, PLEC), and brain metal transport (SLC39A8). These variants have four broad patterns of spatial association with structural connectivity: some have disproportionately strong associations with corticothalamic connectivity, interhemispheric connectivity, or both, while others are more spatially diffuse. Structural connectivity measures are highly polygenic, with a median of 9.1 percent of common variants estimated to have non-zero effects on each measure, and exhibited signatures of negative selection. Structural connectivity measures have significant genetic correlations with a variety of neuropsychiatric and cognitive traits, indicating that connectivity-altering variants tend to influence brain health and cognitive function. Heritability is enriched in regions with increased chromatin accessibility in adult oligodendrocytes (as well as microglia, inhibitory neurons and astrocytes) and multiple fetal cell types, suggesting that genetic control of structural connectivity is partially mediated by effects on myelination and early brain development. Our results indicate pervasive, pleiotropic, and spatially structured genetic control of white-matter structural connectivity via diverse neurodevelopmental pathways, and support the relevance of this genetic control to healthy brain function.
Topics: Adult; Humans; Connectome; Genome-Wide Association Study; Semaphorin-3A; Genes, Regulator; Brain; Protein Kinases; Repressor Proteins; Microfilament Proteins; Intracellular Signaling Peptides and Proteins
PubMed: 38438384
DOI: 10.1038/s41467-024-46023-2 -
Molecular Biology of the Cell Nov 2023Most eukaryotic cells utilize clathrin-mediated endocytosis as well as multiple clathrin-independent pathways to internalize proteins and membranes. Although...
Most eukaryotic cells utilize clathrin-mediated endocytosis as well as multiple clathrin-independent pathways to internalize proteins and membranes. Although clathrin-mediated endocytosis has been studied extensively and many machinery proteins have been identified, clathrin-independent pathways remain poorly characterized by comparison. We previously identified the first known yeast clathrin-independent endocytic pathway, which relies on the actin-modulating GTPase Rho1, the formin Bni1 and unbranched actin filaments, but does not require the clathrin coat or core clathrin machinery proteins. In this study, we sought to better understand clathrin-independent endocytosis in yeast by exploring the role of myosins as actin-based motors, because actin is required for endocytosis in yeast. We find that Myo2, which transports secretory vesicles, organelles and microtubules along actin cables to sites of polarized growth, participates in clathrin-independent endocytosis. Unexpectedly, the ability of Myo2 to transport microtubule plus ends to the cell cortex appears to be required for its role in clathrin-independent endocytosis. In addition, dynein, dynactin, and proteins involved in cortical microtubule capture are also required. Thus, our results suggest that interplay between actin and microtubules contributes to clathrin-independent internalization in yeast.
Topics: Saccharomyces cerevisiae; Actins; Clathrin; Microtubules; Endocytosis; Actin Cytoskeleton; Microfilament Proteins; Saccharomyces cerevisiae Proteins
PubMed: 37647159
DOI: 10.1091/mbc.E23-05-0164 -
Journal of Cellular and Molecular... Jul 2023Tensin 1 was originally described as a focal adhesion adaptor protein, playing a role in extracellular matrix and cytoskeletal interactions. Three other Tensin proteins... (Review)
Review
Tensin 1 was originally described as a focal adhesion adaptor protein, playing a role in extracellular matrix and cytoskeletal interactions. Three other Tensin proteins were subsequently discovered, and the family was grouped as Tensin. It is now recognized that these proteins interact with multiple cell signalling cascades that are implicated in tumorigenesis. To understand the role of Tensin 1-3 in neoplasia, current molecular evidence is categorized by the hallmarks of cancer model. Additionally, clinical data involving Tensin 1-3 are reviewed to investigate the correlation between cellular effects and clinical phenotype. Tensin proteins commonly interact with the tumour suppressor, DLC1. The ability of Tensin to promote tumour progression is directly correlated with DLC1 expression. Members of the Tensin family appear to have tumour subtype-dependent effects on oncogenesis; despite numerous data evidencing a tumour suppressor role for Tensin 2, association of Tensins 1-3 with an oncogenic role notably in colorectal carcinoma and pancreatic ductal adenocarcinoma is of potential clinical relevance. The complex interplay between these focal adhesion adaptor proteins and signalling pathways are discussed to provide an up to date review of their role in cancer biology.
Topics: Humans; Tensins; Microfilament Proteins; Signal Transduction; Cytoskeleton; Cell Transformation, Neoplastic; GTPase-Activating Proteins; Tumor Suppressor Proteins
PubMed: 37296531
DOI: 10.1111/jcmm.17714 -
Progress in Neurobiology Nov 2023Angelman Syndrome (AS) is a severe cognitive disorder caused by loss of neuronal expression of the E3 ubiquitin ligase UBE3A. In an AS mouse model, we previously...
Angelman Syndrome (AS) is a severe cognitive disorder caused by loss of neuronal expression of the E3 ubiquitin ligase UBE3A. In an AS mouse model, we previously reported a deficit in brain-derived neurotrophic factor (BDNF) signaling, and set out to develop a therapeutic that would restore normal signaling. We demonstrate that CN2097, a peptidomimetic compound that binds postsynaptic density protein-95 (PSD-95), a TrkB associated scaffolding protein, mitigates deficits in PLC-CaMKII and PI3K/mTOR pathways to restore synaptic plasticity and learning. Administration of CN2097 facilitated long-term potentiation (LTP) and corrected paired-pulse ratio. As the BDNF-mTORC1 pathway is critical for inhibition of autophagy, we investigated whether autophagy was disrupted in AS mice. We found aberrantly high autophagic activity attributable to a concomitant decrease in mTORC1 signaling, resulting in decreased levels of synaptic proteins, including Synapsin-1 and Shank3. CN2097 increased mTORC1 activity to normalize autophagy and restore hippocampal synaptic protein levels. Importantly, treatment mitigated cognitive and motor dysfunction. These findings support the use of neurotrophic therapeutics as a valuable approach for treating AS pathology.
Topics: Animals; Mice; Angelman Syndrome; Brain-Derived Neurotrophic Factor; Hippocampus; Long-Term Potentiation; Mechanistic Target of Rapamycin Complex 1; Microfilament Proteins; Nerve Tissue Proteins; Peptidomimetics; Transcription Factors
PubMed: 37536482
DOI: 10.1016/j.pneurobio.2023.102513 -
Advanced Science (Weinheim,... Aug 2023Autism spectrum disorders (ASDs) include a wide range of neurodevelopmental disorders. Several reports showed that mutations in different high-risk ASD genes lead to...
Autism spectrum disorders (ASDs) include a wide range of neurodevelopmental disorders. Several reports showed that mutations in different high-risk ASD genes lead to ASD. However, the underlying molecular mechanisms have not been deciphered. Recently, they reported a dramatic increase in nitric oxide (NO) levels in ASD mouse models. Here, they conducted a multidisciplinary study to investigate the role of NO in ASD. High levels of nitrosative stress biomarkers are found in both the Shank3 and Cntnap2 ASD mouse models. Pharmacological intervention with a neuronal NO synthase (nNOS) inhibitor in both models led to a reversal of the molecular, synaptic, and behavioral ASD-associated phenotypes. Importantly, treating iPSC-derived cortical neurons from patients with SHANK3 mutation with the nNOS inhibitor showed similar therapeutic effects. Clinically, they found a significant increase in nitrosative stress biomarkers in the plasma of low-functioning ASD patients. Bioinformatics of the SNO-proteome revealed that the complement system is enriched in ASD. This novel work reveals, for the first time, that NO plays a significant role in ASD. Their important findings will open novel directions to examine NO in diverse mutations on the spectrum as well as in other neurodevelopmental disorders. Finally, it suggests a novel strategy for effectively treating ASD.
Topics: Mice; Animals; Autism Spectrum Disorder; Nitric Oxide; Neurons; Biomarkers; Microfilament Proteins; Nerve Tissue Proteins
PubMed: 37212048
DOI: 10.1002/advs.202205783 -
Clinical Research in Cardiology :... Sep 2023In suspected myocardial infarction (MI), guidelines recommend using high-sensitivity cardiac troponin (hs-cTn)-based approaches. These require fixed assay-specific...
BACKGROUND
In suspected myocardial infarction (MI), guidelines recommend using high-sensitivity cardiac troponin (hs-cTn)-based approaches. These require fixed assay-specific thresholds and timepoints, without directly integrating clinical information. Using machine-learning techniques including hs-cTn and clinical routine variables, we aimed to build a digital tool to directly estimate the individual probability of MI, allowing for numerous hs-cTn assays.
METHODS
In 2,575 patients presenting to the emergency department with suspected MI, two ensembles of machine-learning models using single or serial concentrations of six different hs-cTn assays were derived to estimate the individual MI probability (ARTEMIS model). Discriminative performance of the models was assessed using area under the receiver operating characteristic curve (AUC) and logLoss. Model performance was validated in an external cohort with 1688 patients and tested for global generalizability in 13 international cohorts with 23,411 patients.
RESULTS
Eleven routinely available variables including age, sex, cardiovascular risk factors, electrocardiography, and hs-cTn were included in the ARTEMIS models. In the validation and generalization cohorts, excellent discriminative performance was confirmed, superior to hs-cTn only. For the serial hs-cTn measurement model, AUC ranged from 0.92 to 0.98. Good calibration was observed. Using a single hs-cTn measurement, the ARTEMIS model allowed direct rule-out of MI with very high and similar safety but up to tripled efficiency compared to the guideline-recommended strategy.
CONCLUSION
We developed and validated diagnostic models to accurately estimate the individual probability of MI, which allow for variable hs-cTn use and flexible timing of resampling. Their digital application may provide rapid, safe and efficient personalized patient care.
TRIAL REGISTRATION NUMBERS
Data of following cohorts were used for this project: BACC ( www.
CLINICALTRIALS
gov ; NCT02355457), stenoCardia ( www.
CLINICALTRIALS
gov ; NCT03227159), ADAPT-BSN ( www.australianclinicaltrials.gov.au ; ACTRN12611001069943), IMPACT ( www.australianclinicaltrials.gov.au , ACTRN12611000206921), ADAPT-RCT ( www.anzctr.org.au ; ANZCTR12610000766011), EDACS-RCT ( www.anzctr.org.au ; ANZCTR12613000745741); DROP-ACS ( https://www.umin.ac.jp , UMIN000030668); High-STEACS ( www.
CLINICALTRIALS
gov ; NCT01852123), LUND ( www.
CLINICALTRIALS
gov ; NCT05484544), RAPID-CPU ( www.
CLINICALTRIALS
gov ; NCT03111862), ROMI ( www.
CLINICALTRIALS
gov ; NCT01994577), SAMIE ( https://anzctr.org.au ; ACTRN12621000053820), SEIGE and SAFETY ( www.
CLINICALTRIALS
gov ; NCT04772157), STOP-CP ( www.
CLINICALTRIALS
gov ; NCT02984436), UTROPIA ( www.
CLINICALTRIALS
gov ; NCT02060760).
Topics: Humans; Angina Pectoris; Biomarkers; Myocardial Infarction; ROC Curve; Troponin I; Troponin T; Clinical Studies as Topic
PubMed: 37131096
DOI: 10.1007/s00392-023-02206-3 -
Nature Communications Sep 2023Small ubiquitin-like modifier (SUMO) typically conjugates to target proteins through isopeptide linkage to the ε-amino group of lysine residues. This posttranslational...
Small ubiquitin-like modifier (SUMO) typically conjugates to target proteins through isopeptide linkage to the ε-amino group of lysine residues. This posttranslational modification (PTM) plays pivotal roles in modulating protein function. Cofilins are key regulators of actin cytoskeleton dynamics and are well-known to undergo several different PTMs. Here, we show that cofilin-1 is conjugated by SUMO1 both in vitro and in vivo. Using mass spectrometry and biochemical and genetic approaches, we identify the N-terminal α-amino group as the SUMO-conjugation site of cofilin-1. Common to conventional SUMOylation is that the N-α-SUMOylation of cofilin-1 is also mediated by SUMO activating (E1), conjugating (E2), and ligating (E3) enzymes and reversed by the SUMO deconjugating enzyme, SENP1. Specific to the N-α-SUMOylation is the physical association of the E1 enzyme to the substrate, cofilin-1. Using F-actin co-sedimentation and actin depolymerization assays in vitro and fluorescence staining of actin filaments in cells, we show that the N-α-SUMOylation promotes cofilin-1 binding to F-actin and cofilin-induced actin depolymerization. This covalent conjugation by SUMO at the N-α amino group of cofilin-1, rather than at an internal lysine(s), serves as an essential PTM to tune cofilin-1 function during regulation of actin dynamics.
Topics: Actins; Sumoylation; Lysine; Actin Depolymerizing Factors; Ubiquitin
PubMed: 37709794
DOI: 10.1038/s41467-023-41520-2 -
Biochemical and Biophysical Research... Dec 2023Proteins of the gelsolin family are Ca2+-dependent, multifunctional, actin-binding proteins containing three (S1-S3, about 40 kDa) or six (S1-S6, about 80 kDa) highly...
Proteins of the gelsolin family are Ca2+-dependent, multifunctional, actin-binding proteins containing three (S1-S3, about 40 kDa) or six (S1-S6, about 80 kDa) highly conserved repeats in the amino acid sequence. The pattern of interaction of these proteins with actin is complex: they can sever actin filaments; promote polymer nucleation after binding to two actin monomers; and cap the growing barbed end of actin filaments. In the present study, an actin polymerizing factor (46 kDa) from the adductor muscle of a bivalve mollusc has been discovered and identified for the first time. This protein has turned out to belong to the gelsolin family of actin regulatory proteins. The expression of gelsolin-like proteins in the tissues of bivalves was predicted after analyzing their proteome, but this is the first study where an actually expressed protein has been found. A primary determination of its physicochemical properties such as molecular weight, charge, resistance to urea, influence on actin polymerization by viscosity, and light scattering is carried out and the molecular structure analyzed.
Topics: Gelsolin; Actins; Calcium-Binding Proteins; Microfilament Proteins; Muscle, Skeletal; Calcium
PubMed: 37976813
DOI: 10.1016/j.bbrc.2023.149221 -
Molecular Psychiatry Sep 2023Despite intensive studies in modeling neuropsychiatric disorders especially autism spectrum disorder (ASD) in animals, many challenges remain. Genetic mutant mice have...
Despite intensive studies in modeling neuropsychiatric disorders especially autism spectrum disorder (ASD) in animals, many challenges remain. Genetic mutant mice have contributed substantially to the current understanding of the molecular and neural circuit mechanisms underlying ASD. However, the translational value of ASD mouse models in preclinical studies is limited to certain aspects of the disease due to the apparent differences in brain and behavior between rodents and humans. Non-human primates have been used to model ASD in recent years. However, a low reproduction rate due to a long reproductive cycle and a single birth per pregnancy, and an extremely high cost prohibit a wide use of them in preclinical studies. Canine model is an appealing alternative because of its complex and effective dog-human social interactions. In contrast to non-human primates, dog has comparable drug metabolism as humans and a high reproduction rate. In this study, we aimed to model ASD in experimental dogs by manipulating the Shank3 gene as SHANK3 mutations are one of most replicated genetic defects identified from ASD patients. Using CRISPR/Cas9 gene editing, we successfully generated and characterized multiple lines of Beagle Shank3 (bShank3) mutants that have been propagated for a few generations. We developed and validated a battery of behavioral assays that can be used in controlled experimental setting for mutant dogs. bShank3 mutants exhibited distinct and robust social behavior deficits including social withdrawal and reduced social interactions with humans, and heightened anxiety in different experimental settings (n = 27 for wild-type controls and n = 44 for mutants). We demonstrate the feasibility of producing a large number of mutant animals in a reasonable time frame. The robust and unique behavioral findings support the validity and value of a canine model to investigate the pathophysiology and develop treatments for ASD and potentially other psychiatric disorders.
Topics: Animals; Dogs; Humans; Autism Spectrum Disorder; CRISPR-Cas Systems; Disease Models, Animal; Gene Editing; Microfilament Proteins; Nerve Tissue Proteins
PubMed: 37848710
DOI: 10.1038/s41380-023-02276-9