Tyrosine phosphorylation of secretion machinery proteins is a crucial regulatory mechanism for exocytosis. However, the participation of protein tyrosine phosphatases (PTPs) in different exocytosis stages has not been defined. Here we demonstrated that PTP-MEG2 controls multiple steps of catecholamine secretion. Biochemical and crystallographic analyses revealed key residues that govern the PTP-MEG2

LAT is a critical regulator of T cell development and function. It organises signalling events at the plasma membrane. However, the mechanism, which controls LAT localisation at the plasma membrane is not fully understood. Here, we studied the impact of helix-breaking amino acids, two prolines and one glycine, in the transmembrane segment on localisation and function of LAT. Using in silico analysis

Muscle stem cells (MuSCs) are indispensable for muscle regeneration. A multitude of extracellular stimuli affect MuSCs from quiescent progenitors to differentiated myocytes, the activity of which is modulated by coreceptors such as syndecan-3 (SDC3). Here we investigated the global landscape of SDC3-mediated regulation of myogenesis using a phosphoproteomics approach which revealed, with the precision

The Polycomb group (PcG) protein chromobox 8 (CBX8) is the subunit of Polycomb repressive complex 1 (PRC1) and recognizes the trimethylation of histone H3 on Lysine 27 (H3K27me3), and coordinates with PRC2 complex to function as epigenetic gene silencer. CBX8 plays a key role in cell proliferation, stem cell biology, cell senescence, and cancer development. However, our knowledge of CBX8 post-translational

To determine whether a consistent pattern of transcriptional deregulation in aging murine hematopoietic stem cells (HSC) exists, we collected all available transcriptome studies of aged HSCs, adding our own unpublished data. Cross-validation of all datasets identified a core list of consistently differentially expressed genes; the HSC aging signature. Despite heterogeneity between individual studies

When endoplasmic reticulum (ER) stress occurs, a collection of phylogenetically conserved signaling pathways, termed unfolded protein response (UPR) pathways, monitors the stress level in the ER and is activated to restore homeostasis. If stress is overwhelming, activation of these signaling pathways also leads to apoptosis. The initial response in the ER is fluxed into several parallel branches, i

Many organisms evolved strategies to survive and thrive under extreme desiccation. Plant seeds protect dehydrated embryos from a variety of stressors and can even lay dormant for millennia. While hydration is the key trigger that reactivates metabolism and kick-starts germination, the exact mechanism by which the embryo senses water remains unresolved. We identified an uncharacterized Arabidopsis thaliana

Many cells and tissues exhibit chirality that stems from the chirality of constituent proteins and polymers. For example, the C. elegans zygote undergoes an actomyosin-driven chiral rotation in which the entire cortex is displaced circumferentially around the division plane during anaphase. This phenomenon thus relates to how force and chirality are translated across scales. Although it is known that

Small-molecule fluorophores enable the observation of biomolecules in their native context with fluorescence microscopy. Specific labelling via bioorthogonal tetrazine chemistry confers minimal label size and rapid labelling kinetics. At the same time, fluorogenic tetrazine-dye conjugates exhibit efficient quenching of dyes prior to target binding. However, live-cell compatible long-wavelength fluorophores

Age-related loss of muscle mass and strength is widely attributed to limitation in the capacity of muscle resident satellite cells to perform their myogenic function. This idea contains two notions that have not been comprehensively evaluated by experiment. First, it entails the idea that we damage and lose substantial amounts of muscle in the course of our normal daily activities. Second, it suggests

Alpha-Synuclein (alpha-Syn) aggregation is a hallmark of devastating neurodegenerative disorders including Parkinsons disease (PD) and multiple systems atrophy (MSA). alpha-Syn aggregates spread throughout the brain during disease progression, suggesting mechanisms of intercellular seeding. Formation of alpha-Syn amyloid fibrils is observed in vitro and fibrillar alpha-Syn has been purified from patient

Physiological liver cell replacement is central to maintaining the organ's high metabolic activity, although its characteristics are difficult to study in humans. Using retrospective 14C birth dating of cells, we report that human hepatocytes show continuous and lifelong turnover, maintaining the liver a young organ (average age < 3 years). Hepatocyte renewal is highly dependent on the ploidy level

Epithelia must eliminate apoptotic cells to preserve tissue barriers and prevent inflammation. Several different mechanisms exist for apoptotic clearance, including efferocytosis and apical extrusion. We found that extrusion was the first-line response to apoptosis in cultured monolayers and in zebrafish epidermis. During extrusion, the apoptotic cell elicited active lamellipodial protrusions and assembly

Background: Muscle stem cells (MuSCs) are requisite for skeletal muscle regeneration and homeostasis. Proper functioning of MuSCs, including activation, proliferation, and fate decision, is determined by an orchestrated series of events and communication between MuSCs and their niche consisting of the host myofiber and neighbouring cells. A multitude of biochemical stimuli are known to regulate fate

The p53/p21 pathway is activated in response to cell stress. However, its role in acute lung injury has not been elucidated. Acute lung injury is associated with disruption of the alveolo-capillary barrier leading to acute respiratory distress syndrome (ARDS). Mechanical ventilation may be necessary to support gas exchange in patients with ARDS, however, high positive airway pressures can cause regional

Robust and effective T cell-mediated immune responses require proper allocation of metabolic resources through metabolic pathways to sustain the energetically costly immune response. As an essential class of polycationic metabolites ubiquitously present in all living organisms, the polyamine pool is tightly regulated by biosynthesis and salvage pathway. We demonstrated that arginine is a major carbon

Abstract Background: Classic articles are defined as research papers with a total citation of one thousand or more. The present study is to identify and analyse the characteristics of the classic articles in apoptosis research. Method: Classic articles with total of 1,000 or more citations from Web of Science Core Collection since year of publication to the end of 2017 were basically assessed regarding

Focal adhesions (FAs) initiate chemical and mechanical signals involved in cell polarity, migration, proliferation and differentiation. Super‐resolution microscopy revealed that FAs are organized at the nanoscale into functional layers from the lower plasma membrane to the upper actin cytoskeleton. Yet, how FAs proteins are guided into specific nano‐layers to promote interaction with given targets

Mutation of the WASH complex subunit, SWIP, is implicated in human intellectual disability, but the cellular etiology of this association is unknown. We identify the neuronal WASH complex proteome, revealing a network of endosomal proteins. To uncover how dysfunction of endosomal SWIP leads to disease, we generate a mouse model of the human WASHC4c.3056C>G mutation. Quantitative spatial proteomics

Because dearth and overabundance of histones result in cellular defects, histone synthesis and demand are typically tightly coupled. In Drosophila embryos, histones H2B/H2A/H2Av accumulate on lipid droplets (LDs), cytoplasmic fat storage organelles. Without this binding, maternally provided H2B/H2A/H2Av are absent; however, the molecular basis of how LDs ensure histone storage is unclear. Using quantitative

Calmodulin (CaM) engages in Ca2+-dependent interactions with numerous proteins, including human Na+/H+-exchanger NHE1. Using nuclear magnetic resonance (NMR) spectroscopy, isothermal titration calorimetry, and fibroblasts expressing wildtype and mutant NHE1, we discovered multiple accessible states of this important complex existing in different NHE1:CaM stoichiometries and structures. We solved the

The formation of vascular tubes is driven by extensive changes in endothelial cell (EC) shape. Here, we have identified a novel role of the actin-binding protein, Marcksl1, in modulating the mechanical properties of EC cortex to regulate cell shape and vessel structure during angiogenesis. Increasing and depleting Marcksl1 expression level in vivo resulted in an increase and decrease, respectively

Exosomes, new players in cell-cell communication, are extracellular vesicles of endocytic origin. Although single cells are known to release various kinds of exosomes (referred to as exosomal heterogeneity), very little is known about the mechanisms by which they are produced and released. Here, we established methods for studying exosomal heterogeneity by using polarized epithelial cells and showed

Single-cell RNA sequencing combined with spatial information on landmark genes enables reconstruction of spatially-resolved tissue cell atlases. However, such approaches are challenging for rare cell types, since their mRNA contents are diluted in the spatial transcriptomics bulk measurements used for landmark gene detection. In the small intestine, enterocytes, the most common cell type, exhibit zonated

This work presents a successful methodology to image mammalian cells adhered to nanostructured biomaterials using scanning electron microscopy (SEM) operating in low-vacuum mode following ionic liquid treatment. Human osteoblast-like Saos-2 cells were treated with a room-temperature ionic liquid, 1-Ethyl-3-methylimidazolium tetrafluoroborate, and subsequently imaged on titanium utilizing SEM. Titanium

Hematopoietic stem cell transplantation (HSCT) following myeloablative conditioning represents the only curative treatment option to overcome numerous hematologic malignancies. Despite the overall clinical success to achieve reconstitution of the blood system in many patients, the length of the aplastic phase until recovery response remains a critical parameter for patient survival. Fatal infections

The drive to withstand environmental stresses and defend against invasion is a universal trait extant in all forms of life. While numerous canonical signaling cascades have been characterized in detail, it remains unclear how these pathways interface to generate coordinated responses to diverse stimuli. To dissect these connections, we follow heparanase (HPSE), a protein best known for its endoglycosidic

Cytoplasmic RNA granules compartmentalize processes involving translation. It remains unclear, however, whether any RNA granule carries out translation quality control, the pathways wherein defective mRNAs and nascent polypeptides are released from stalled ribosomes and targeted for degradation. We previously reported on the localization of oxidized RNA in human cells to cytoplasmic foci called oxidized

Fluorescent biosensors routinely yield thousands of single-cell, heterogeneous, multidimensional signaling trajectories that are difficult to mine for relevant information. We present CODEX, an approach based on artificial neural networks to guide exploration of time-series datasets and to identify motifs in dynamic signaling states.

The processes underlying formation and growth of unfolded protein inclusions are relevant to neurodegenerative diseases. In S. cerevisiae, inclusion bodies formed by mutant huntingtin have characteristics of phase-separated compartments: they are mobile, ovoid, and the contents are diffusible. We have used molecular genetics and quantitative confocal microscopy to probe the relationship between concentration

Induced pluripotent stem cells (iPSCs) provide a great model to study the process of stem cell reprogramming and differentiation. Single-cell RNA sequencing (scRNA-seq) enables us to investigate the reprogramming process at single-cell level. Here, we introduce single-cell entropy (scEntropy) as a macroscopic variable to quantify the cellular transcriptome from scRNA-seq data during reprogramming and

Macroautophagy is a conserved degradation pathway, which mediates cellular homeostasis by the delivery of harmful substances into lysosomes. This is achieved by the sequestration of these substances referred to as cargo within double membrane vesicles, the autophagosomes, which form de novo. Among the many cargoes that are targeted by autophagy are condensates containing p62 and ubiquitinated proteins

In prophase of meiosis I, homologous partner chromosomes pair and become connected by crossovers. Chiasmata, the connections formed between the partners enable the chromosome pair, called a bivalent, to attach as a single unit to the spindle. When the meiosis I spindle forms in prometaphase, most bivalents are associated with a single spindle pole and go through a series of oscillations on the spindle

In de novo purine biosynthesis (DNPS), 5-aminoimidazole-4-carboxamide ribonucleotide formyltransferase (2.1.2.3) / inosine monophosphate cyclohydrolase (3.5.4.10) (ATIC) catalyzes the last two reactions of the pathway: conversion of 5-aminoimidazole-4-carboxamide ribonucleotide [aka Z-nucleotide monophosphate (ZMP)] to 5-formamido-4-imidazolecarboxamide ribonucleotide (FAICAR) then to inosine monophosphate

Cartilage tissue has been recalcitrant to tissue engineering approaches. In this study, human chondrocytes were formed into self-assembled cartilage sheets, cultured in physiologic (5%) and atmospheric (20%) oxygen conditions and underwent biochemical, histological and biomechanical analysis at one- and two-months. The results indicated that sheets formed at physiological oxygen tension were thicker

The ability of epithelial tissues to heal after injury is essential for animal life, yet the mechanisms by which epithelial cells sense tissue damage are incompletely understood. In aquatic organisms such as zebrafish, osmotic shock following injury is believed to be an early and potent activator of a wound response. We find that, in addition to sensing osmolarity, basal skin cells in zebrafish larvae

Since cell penetrating peptides are promising tools for delivery of cargo into cells, factors limiting or facilitating their cellular uptake are intensely studied. Using labeling with pH-insensitive and pH-sensitive dyes we report that escape of penetratin from acidic endo-lysosomal compartments is retarded compared to its cellular uptake. The membrane dipole potential, known to alter transmembrane

CRISPR/Cas9 gene editing is effective in manipulating genetic loci in mammalian cell cultures and whole fish but efficient platforms applicable to fish cell lines are currently limited. Our initial attempts to employ this technology in fish cell lines using heterologous promoters or a ribonucleoprotein approach failed to indicate genomic alteration at targeted sites in a tilapia brain cell line (OmB)

Cell death is an essential process in biology that must be accounted for in live microscopy experiments. Nevertheless, cell death is difficult to detect without perturbing experiments with stains, dyes or biosensors that can bias experimental outcomes, lead to inconsistent results, and reduce the number of processes that can be simultaneously labelled. These additional steps also make live microscopy

We compared four orthogonal technologies for sizing, counting, and phenotyping of extracellular vesicles (EVs) and synthetic particles. The platforms were: single-particle interferometric reflectance imaging sensing (SP-IRIS) with fluorescence, nanoparticle tracking analysis (NTA) with fluorescence, microfluidic resistive pulse sensing (MRPS), and nanoflow cytometry measurement (NFCM). Results were

Lowe Syndrome (LS) is a lethal genetic disorder caused by mutations in the OCRL1 gene, which encodes the lipid 5 phosphatase Ocrl1. Patients exhibit a characteristic triad of symptoms including eyes, brain and kidneys abnormalities with renal failure as the most common cause of death. Over 200 OCRL1 mutations have been identified in LS, but their specific impact on cellular processes is unknown. Despite

Although centromeres play a key role in sister chromatid separation and segregation, mitotic transmission of chromosome fragments lacking a centromere (acentrics) can be successful. In Drosophila neuroblasts, acentric chromosomes undergo delayed, but successful transmission revealing the existence of kinetochore-independent mechanisms driving transmission. In spite of delayed sister chromatid separation

Proper formation and maintenance of the mitotic spindle is required for faithful cell division. While much work has been done to understand the roles of the key force components of the mitotic spindle, identifying the consequences of force perturbations in the spindle remains a challenge. We develop a computational framework accounting for the minimal force requirements of mitotic progression. To reflect

Replication forks must respond to changes in nutrient conditions, especially in bacterial cells. By investigating the single molecule dynamics of replicative helicase DnaC, DNA primase DnaG, and of lagging strand polymerase DnaE in the model bacterium Bacillus subtilis in response to transient replication blocks due to DNA damage, to inhibition of the replicative polymerase, or to downshift of serine

Severe malaria caused by Plasmodium falciparum poses a major global health problem with high morbidity and mortality. The P. falciparum harbours a family of pore forming proteins (PFPs), known as perforin like proteins (PLPs), which are structurally equivalent to prokaryotic PFPs. These PLPs are secreted from the parasites and by interacting to host cells they contribute to disease pathogenesis. The

The endothelium responds to chemical and mechanical factors in regulating vascular tone, angiogenesis, blood pressure and blood flow. The endothelial volume regulatory anion channel (VRAC) has been proposed to be mechano-sensitive, to activate in response to fluid flow/hydrostatic pressure and putatively regulate vascular reactivity and angiogenesis. Here, we show that the Leucine Rich Repeat Containing

Nanoscale bending of plasma membrane increases cell adhesion, induces cell-signalling, triggers F-actin assembly and endocytosis in tissue-cultured cells. The underlying mechanisms are not very well understood. Here, we show that stretching the plasma membrane of somatic cyst cell around rigid spermatid heads generates a stable, tubular endomembrane scaffold supported by contractile actomyosin. The

It has been known that SARS-CoV-2 which is considered similar to SARS-CoV invades human respiratory epithelial cells through interaction with the human angiotensin converting enzyme II (ACE2). In this work, SARS-CoV-2S-RBD and its cell receptor ACE2 were used to investigate the blocking effect and mechanism of β-chitosan to the binding of them. Besides, inhibitory effect of β-chitosan on inflammation

As we age, our tissues are repeatedly challenged by mutational insult, yet cancer occurrence is a relatively rare event. Cells carrying cancer-causing genetic mutations compete with normal neighbours for space and survival in tissues. However, the mechanisms underlying mutant-normal competition in adult tissues and the relevance of this process to cancer remain incompletely understood. Here, we investigate

Cellular senescence restrains the expansion of neoplastic cells through several layers of regulation, including epigenetic decoration of chromatin structure and functional modulation of bioactive components. Here we report that expression of the histone H3-specific demethylase KDM4 is upregulated in human stromal cells upon cellular senescence. In clinical oncology, upregulated KDM4 and diminished

Accurate chromosome segregation requires kinetochores on duplicated chromatids to biorient by attaching to dynamic microtubules from opposite spindle poles, which exerts forces to bring kinetochores under tension. However, kinetochores initially bind to MTs indiscriminately, resulting in errors that must be corrected. While the Aurora B protein kinase destabilizes low-tension attachments by phosphorylating

Mammalian X-chromosome dosage balance is regulated by X-chromosome inactivation (XCI) and X-chromosome upregulation (XCU), but the dynamics of XCU as well as the interplay between the two mechanisms remain poorly understood. Here, we mapped XCU throughout early mouse embryonic development at cellular and allelic resolution, revealing sex- and lineage-specific dynamics along key events in X-chromosome

The endocytic pathway actively interacts with mitochondria in maintaining cellular homeostasis. However, how the dysfunction of this inter-organelle interaction causing pathological outcomes remains less understood. Here we show that an aberrant endocytic pathway from the deficiency of CHMP5 in skeletal progenitor cells causes accumulation of functionally compromised mitochondria, which induce cellular

Centrosomal P4.1-associated protein (CPAP) plays a critical role in restricting the centriole length in human cells. Here, we report a novel positive regulatory role for CPAP in endosome maturation during internalized-cell surface receptor trafficking. We found that CPAP is required for targeting ligand-bound cell surface receptor to the lysosome for degradation. While routing of ligand-engaged receptor

Despite of a boost of recent progress in dynamic single-cell measurements and analyses in E. coli, we still lack a mechanistic understanding of the determinants of the decision to divide. Specifically, the debate is open regarding the hierarchy of processes linking growth and chromosome replication to division, and on the molecular origin of the observed "adder correlations", whereby cells divide adding

Cell migration in 3D micro-environments is a complex process which depends on the coordinated activity of leading edge protrusive force and rear retraction in a push-pull mechanism. While the potentiation of protrusions has been widely studied, the precise signalling and mechanical events that lead to forward movement of the cell rear are much less well understood, particularly in physiological 3D

The Src tyrosine kinase controls cancer-critical protein glycosylation through Golgi to ER relocation of GALNTs enzymes. How Src induces this trafficking event is unknown. Golgi to ER transport depends on the GTP Exchange factor (GEF) GBF1 and small GTPase Arf1. Here we show that Src induces the formation of tubular transport carriers containing GALNTs through the activation of a GBF1-Arf1 complex

The current increase in the use of multi-herbal remedies coupled with loose regulation on public access to these products underscore research efforts to evaluate their biochemical effect, noting that many of the herbal medicines lack scientific evidence to support their medicinal claims. Objective: We therefore investigated the potential genotoxicity and hematotoxicity of commonly consumed multi-herbal

Aging is associated with increased morbidity and high economic costs due to a burdened healthcare system and decreased workforce. Parabiotic animal models indicated that secretome from young cells can restore aged tissue functions. We used a heterochronic co-culture system with young and aged mobilized peripheral blood (MPB) or umbilical cord blood (UCB) and showed hematopoietic restoration, independent

COVID-19 affects vulnerable populations including elderly individuals and patients with cancer. Natural Killer (NK) cells and innate-immune TRAIL suppress transformed and virally-infected cells. ACE2, and TMPRSS2 protease promote SARS-CoV-2 infectivity, while inflammatory cytokines IL-6, or G-CSF worsen COVID-19 severity. We show MEK inhibitors (MEKi) VS-6766, trametinib and selumetinib reduce ACE2