The smallest arenavirus gene product, Z protein, plays critical roles in the virus life cycle. Z is the major driving force of budding and particle production because of a unique property that defines self-assembly. In addition to the roles in budding, Z also participates in the suppression of type I interferon production to evade host antiviral immunity. Therefore, Z and its assembled form are an

The somatic haploidy is unstable in diplontic animals, but cellular processes determining haploid stability remain elusive. Here, we found that inhibition of mevalonate pathway by pitavastatin, a widely used cholesterol-lowering drug, drastically destabilized the haploid state in HAP1 cells. Interestingly, cholesterol supplementation did not restore haploid stability in pitavastatin-treated cells,

Prickle2 has been identified in genetic studies of subjects with autism spectrum disorder (ASD) and epilepsy, but the pathological mechanism of Prickle2 remains to be fully understood. Proteomic analysis of Prickle2 with mass spectrometry revealed twenty-eight Prickle2 interactors, including immunoglobulin superfamily member 9b (Igsf9b), in the brain. Here, because Igsf9 family proteins are associated

The activity of AMPA-type glutamate receptor is involved in insulin release from pancreatic β-cells. However, the mechanism and dynamics that underlie AMPA receptor-mediated insulin release in β-cells is largely unknown. Here, we show that AMPA induces internalization of glutamate receptor 2/3 (GluR2/3), AMPA receptor subtype, in the mouse β-cell line MIN6. Immunofluorescence experiments showed that

Tissue absorbance, light scattering, and autofluorescence are significantly lower in the near-infrared (NIR) range than in the visible range. Because of these advantages, NIR fluorescent proteins (FPs) are in high demand for in vivo imaging. Nevertheless, application of NIR FPs such as iRFP is still limited due to their dimness in mammalian cells. In contrast to GFP and its variants, iRFP requires

Mechanistic target of rapamycin complex 1 (mTORC1) plays a pivotal role in controlling cell growth and metabolism in response to nutrients and growth factors. The activity of mTORC1 is dually regulated by amino acids and growth factor signaling, and amino acid-dependent mTORC1 activity is regulated by mTORC1 interaction with the Ragulator-Rag GTPase complex, which is localized to the surface of lysosomes

Collagen is the most abundant protein in animal tissues and is critical for their proper organization. Nascent procollagens in the endoplasmic reticulum (ER) are considered too large to be loaded into coat protein complex II (COPII) vesicles, which have a diameter of 60–80 nm, for exit from the ER and transport to the Golgi complex. To study the transport mechanism of procollagen IV, which generates

Endocytic cargos are transported to recycling endosomes (RE) but how these sorting platforms are generated is not well understood. Here we describe our biochemical and live imaging studies of the conserved MON2-DOPEY complex in RE formation. MON2 mainly co-localized with RE marker RAB4B in peripheral dots and perinuclear region. The peripheral RE approached, interacted with, and separated from sorting

It is often assumed that α-subunit phosphorylation of the eukaryotic translation initiation factor 2 (eIF2) complex is just a mechanism to control protein synthesis. However, eIF2α phosphorylation induced by multiple kinases can recognize various intracellular and extracellular stress conditions, and it is involved in various other cellular processes beyond protein synthesis. This review introduces

Centrosomes are highly conserved organelles that act as the major microtubule-organizing center (MTOC) in animal somatic cells. Through their MTOC activity, centrosomes play various roles throughout the cell cycle, such as supporting cell migration in interphase and spindle organization and positioning in mitosis. Various approaches for removing centrosomes from somatic cells have been developed and

Keratinocytes uptake melanosomes from melanocytes and retain them in the perinuclear region, where they form melanin caps. Although these processes are crucial to protecting nuclear DNA against ultraviolet injury, the molecular basis of melanosome uptake and decomposition in keratinocytes is poorly understood. One of the major reasons for its being poorly understood is the lack of a specific marker

The polytopic plasma membrane protein Rim21 senses both the elevation of ambient pH and alterations in plasma membrane lipid asymmetry in the Rim101 pathway in budding yeast. Rim21 is known to undergo N-glycosylation, but the site and function of the glycosylation modification is not known. Using a systematic mutation analysis, we found that Rim21 is N-glycosylated at an unconventional motif located

The oncogenic tyrosine kinase BCR-ABL activates a variety of signaling pathways and plays a causative role in the pathogenesis of chronic myelogenous leukemia (CML); however, the subcellular distribution of this chimeric protein remains controversial. Here, we report that BCR-ABL is localized to stress granules and that its granular localization contributes to BCR-ABL-dependent leukemogenesis. BCR-ABL-positive

The discovery of fluorescent proteins (FPs) has revolutionized cell biology. The fusion of targeting sequences to FPs enables the investigation of cellular organelles and their dynamics; however, occasionally, such fluorescent fusion proteins (FFPs) exhibit behavior different from that of the native proteins. Here, we constructed a color pallet comprising different organelle markers and found that

The Golgi apparatus is an organelle where membrane or secretory proteins receive post-translational modifications such as glycosylation and sulfation, after which the proteins are selectively transported to their final destinations through vesicular transport. When the synthesis of secretory or membrane proteins is increased and overwhelms the capacity of the Golgi (Golgi stress), eukaryotic cells

In yeast Saccharomyces cerevisiae cells, some aberrant multimembrane-spanning proteins are not transported to the cell surface but form and are accumulated in endoplasmic reticulum (ER)-derived subcompartments, known as the ER-associated compartments (ERACs), which are observed as puncta under fluorescence microscopy. Here we show that a mutant of the cell surface protein Pma1, Pma1-2308, was accumulated

Drosophila Mxc protein is a component of the histone locus body (HLB), which is required for the expression of canonical histone genes, and severe mxc mutations generate tumors in larval hematopoietic tissues. A common characteristic of cancer cells is chromosomal instability (CIN), but whether mxc mutants exhibit this feature is unknown. Here, examination of post-meiotic spermatids created after male

Every organism has a different set of genes essential for its viability. This indicates that an organism can become tolerant to the loss of an essential gene under certain circumstances during evolution, via the manifestation of 'masked' alternative mechanisms. In our quest to systematically uncover masked mechanisms in eukaryotic cells, we developed an extragenic suppressor screening method using

The coat protein complex II (COPII) generates transport carriers that deliver newly synthesized proteins from the endoplasmic reticulum (ER) to the Golgi apparatus. The small GTPase Sar1 is a well-known regulator of the assembly of the COPII coat. In the present study, we demonstrate that, besides its well-established role in ER-to-Golgi trafficking, the nuclear localization of Sar1 is essential for

In research on cell biology, organelles have been a major unit of such analyses. Researchers have assumed that the inside of an organelle is almost uniform in regards to its function, even though each organelle has multiple functions. However, we are now facing conundrums that cannot be resolved so long as we regard organelles as functionally uniform units. For instance, how can cells control the diverse

Endocytosis mediates the internalization and ingestion of a variety of endogenous or exogenous substances, including virus particles, under the control of intracellular signaling pathways. We have previously reported that the complex formed between the small GTPase Ras and phosphoinositide 3-kinase (PI3K) translocates from the plasma membrane to endosomes, signaling from which thereby regulates clathrin-independent

Retinoblastoma (RB) is the most common intraocular malignancy in childhood, and the prognosis in the advanced RB is poor. It is urgent to find novel therapeutic targets. Long noncoding RNAs (lncRNAs) have critical functions in cancer progression, and lncRNA LINC00202 is found associated with poor prognosis in RB. However, the functions of LINC00202 in RB remain unclear. We employed qRT-PCR and immunoblot

Two decades have passed since the development of the first calcium indicator based on the green fluorescent protein (GFP) and the principle of Förster resonance energy transfer (FRET). During this period, researchers have advanced many novel ideas for the improvement of such genetically encoded FRET biosensors, which have allowed them to expand their targets from small molecules to signaling proteins

PUM2, an RNA binding protein, is known to promote stem cell proliferation via repressing expressions of cell cycle genes. Similar with stem cells, malignant cells are characterized by unlimited proliferation and remote migration. However, roles of PUM2 in cancer development are controversial. Here, we investigated PUM2's role in glioblastoma development and its relationship with the cell cycle regulator

Ovarian cancer (OC) is one of prevalent tumors and this study aimed to explore CCL20's effects on doxorubicin resistance of OC and related mechanisms. Doxorubicin-resistant SKOV3 DR cells were established from SKOV3 cells via 6-month continuous exposure to gradient concentrations of doxorubicin. Quantitative PCR and Western blot assay showed that SKOV3 DR cells had higher level of CCL20 than SKOV3

Infantile hemangioma is the most common soft tissue tumors in childhood. In clinic, propranolol is widely used for infantile hemangioma therapy. However, some of the infantile hemangioma patients display resistance to propranolol treatment. Previous studies show that miR-187-3p is inhibited in hepatocellular carcinoma and lung cancer, while the role of miR-187-3p in infantile hemangioma remains unclear

KCBP is a microtubule (MT) minus-end-directed kinesin widely conserved in plants. It was shown in Arabidopsis that KCBP controls trichome cell shape by orchestrating MT and actin cytoskeletons using its tail and motor domains. In contrast, the KCBP knockout (KO) line in the moss Physcomitrella patens showed a defect in nuclear and organelle positioning in apical stem cells. Moss KCBP is postulated

Recombinant glycoproteins produced in mammalian cells are clinically indispensable drugs used to treat a broad spectrum of diseases. Their bio-manufacturing process is laborious, time consuming, and expensive. Investment in expediting the process and reducing its cost is the subject of continued research. The PI3K/Akt/mTOR signaling pathway is a key regulator of diverse physiological functions such

The Golgi stress response is a homeostatic mechanism that augments the functional capacity of the Golgi apparatus when Golgi function becomes insufficient (Golgi stress). Three response pathways of the Golgi stress response have been identified in mammalian cells, the TFE3, HSP47 and CREB3 pathways, which augment the capacity of specific Golgi functions such as N-glycosylation, anti-apoptotic activity

Glycans, including glycosphingolipids, are broadly expressed in plasma membranes and play important roles in cell-cell interactions. Recently, it has been revealed that glycans participate in the regulation of malignant phenotypes of cancer cells, e.g. growth and invasion. However, their roles in irradiation-tolerant cancer cells have not yet been elucidated. In this study, we show that specific glycosphingolipids

The Warburg effect is one of the hallmarks of cancer cells, characterized by enhanced aerobic glycolysis. Despite intense research efforts, its functional relevance or biological significance to facilitate tumor progression is still debatable. Hence the question persists when and how the Warburg effect contributes to carcinogenesis. Especially, the role of metabolic changes at a very early stage of

Automatic cell segmentation is a powerful method for quantifying signaling dynamics at single-cell resolution in live cell fluorescence imaging. Segmentation methods for mononuclear and round shape cells have been developed extensively. However, a segmentation method for elongated polynuclear cells, such as differentiated C2C12 myotubes, has yet to be developed. In addition, myotubes are surrounded

Proper N-glycosylation of proteins is important for normal brain development and nervous system function. Identification of the localization, carrier proteins and interacting partners of N-glycans is essential for understanding the roles of glycoproteins. The present study examined the N-glycan A2G'2F (Galβ1-3GlcNAcβ1-2Manα1-6[Galβ1-3GlcNAcβ1-2Manα1-3]Manβ1-4GlcNAcβ1-4[Fucα1-6]GlcNAc-). A2G'2F has

The anti-oxidative property of mesoporous silica nanoparticles (MSNs) has been proposed previously, which prompted us to investigate the potential protective effect of MSNs on human embryonic stem cells (hESCs) against oxidative stress. To this purpose, the cell viability was determined by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide assay. Apoptosis was analyzed by Annexin V/propidium

For more than a century, hematoxylin and eosin (H&E) staining has been the de facto standard for histological studies. Consequently, the legacy of histological knowledge is largely based on H&E staining. Due to the recent advent of multi-photon excitation microscopy, the observation of live tissue is increasingly being used in many research fields. Adoption of this technique has been further accelerated

The Golgi apparatus is a central station for protein trafficking in eukaryotic cells. A widely accepted model of protein transport within the Golgi apparatus is cisternal maturation. Each cisterna has specific resident proteins, which are thought to be maintained by COPI-mediated transport. However, the mechanisms underlying specific sorting of these Golgi-resident proteins remain elusive. To obtain

It takes several months to form the 3-dimensional morphology of the human embryonic brain. Therefore, establishing a long-term culture method for neuronal tissues derived from human induced pluripotent stem (iPS) cells is very important for studying human brain development. However, it is difficult to keep primary neurons alive for more than 3 weeks in culture. Moreover, long-term adherent culture

Epithelial tubules, consisting of the epithelial cell sheet with a central lumen, are the basic structure of many organs. Mechanical forces play an important role in epithelial tubulogenesis; however, little is known about the mechanisms controlling the mechanical forces during epithelial tubule morphogenesis. Solo (also known as ARHGEF40) is a RhoA-targeting guanine-nucleotide exchange factor that

Although the definition of a noncoding RNA (ncRNA) is an RNA molecule that does not encode a protein, recent evidence has revealed that some ncRNAs are indeed translated to give rise to small polypeptides (usually containing fewer than 100 amino acids). Despite their small size, however, these peptides are often biologically relevant in that they are required for a variety of cellular processes. In

Protein kinases play pivotal roles in intracellular signal transduction, and dysregulation of kinases leads to pathological results such as malignant tumors. Kinase activity has hitherto been measured by biochemical methods such as in vitro phosphorylation assay and western blotting. However, these methods are less useful to explore spatial and temporal changes in kinase activity and its cell-to-cell

Collapsin response mediator protein 2 (CRMP2) regulates neuronal polarity by controlling microtubule dynamics. CRMP2 activity is regulated by semaphorin-induced phosphorylation at the C-terminal tail domain. Unphosphorylated CRMP2 induces effective axonal microtubule formation to give the axonal characteristics to a neurite, whereas phosphorylated CRMP2 leads to the apparently opposite effect, growth

Stabilisation of minus ends of microtubules (MTs) is critical for organising MT networks in land plant cells, in which all MTs are nucleated independent of centrosomes. Recently, Arabidopsis SPIRAL2 (SPR2) protein was shown to localise to plus and minus ends of cortical MTs, and increase stability of both ends. Here, we report molecular and functional characterisation of SPR2 of the basal land plant

The Golgi apparatus is a key station of glycosylation and membrane traffic. It consists of stacked cisternae in most eukaryotes. However, the mechanisms how the Golgi stacks are formed and maintained are still obscure. The model plant Arabidopsis thaliana provides a nice system to observe Golgi structures by light microscopy, because the Golgi in A. thaliana is in the form of mini-stacks that are distributed

Inflammatory bowel disease (IBD) is a refractory disease of the gastrointestinal tract that is believed to develop in genetically susceptible individuals. Glycosylation, a type of post-translational modification, is involved in the development of a wide range of diseases, including IBD, by modulating the function of various glycoproteins. To identify novel genes contributing to the development of IBD

Genomics and proteomics studies in Chlamydomonas have revealed that an axoneme is composed of 200-600 types of proteins, including uncharacterized proteins collectively named flagellar-associated proteins (FAPs). Nine FAPs contain the EF-hand motif; however, they have not yet been well characterized. To find components responsible for Chlamydomonas-specific waveform changes coupled with intracellular

The submandibular gland (SMG) is one of the major salivary glands that play important roles for variety of physiological functions, such as digestion of foods, prevention of infection, and lubrication of the mouth. Dysfunction of the SMG, often associated with a salivary inflammation, adversely influences a person's quality of life. However, the mechanism underlying inflammation-driven dysfunction

Bone marrow stromal cells, including endothelial cells and mesenchymal stromal cells, support the maintenance, differentiation, and retention of hematopoietic stem and precursor cells under steady state conditions. At the onset of an emergency, such as severe blood loss or infection, the status of hematopoiesis in the bone marrow changes rapidly to ensure efficient production of cells of specific lineages;

Deltamethrin (DM), a type II pyrethroid, robustly increases brain-derived neurotrophic factor (Bdnf) expression and has a neurotrophic effect in primary cultures of rat cortical neurons. In this study, we investigated the effect of DM on neurite morphology in cultured rat cortical neurons. DM significantly increased neurite outgrowth, but this increase was abolished when the BDNF scavenger tropomyosin

Actin, a major component of microfilaments, is involved in various eukaryotic cellular functions. Over the past two decades, actin fused with fluorescent protein has been used as a probe to detect the organization and dynamics of the actin cytoskeleton in living eukaryotic cells. It is generally assumed that the expression of fusion protein of fluorescent protein does not disturb the distribution of

BACKGROUND Liver fibrosis is the response of liver diseases that puzzles patients. MiRNAs were involved in the regulating processes of liver fibrosis. This study aims to investigate the effects of ARRB1 mediated by miR-29a and miR-652 on liver fibrosis and its possible mechanism. METHODS Liver fibrosis of mice was induced by intraperitoneal injection of CCl4. Liver function was observed by the levels

The dedicator of cytokinesis (DOCK) family proteins are known as one of guanine nucleotide exchange factors (GEFs), that contribute to cellular signaling processes by activating small G proteins. Although mammalian Zizimin is known to be a GEF for Cdc42 of Rho family small GTPase, its role in vivo is not well understood. Here we studied in vivo function of Drosophila Zizimin (Ziz). Knockdown of Ziz

Stem cells from human exfoliated deciduous teeth (SHED) are isolated from the dental pulp tissue of primary teeth and can differentiate into neuronal cells. Although SHED are a desirable type of stem cells for transplantation therapy and for the study of neurological diseases, a large part of the neuronal differentiation machinery of SHED remains unclear. Recent studies have suggested that mitochondrial

Accumulation of unfolded/misfolded proteins in the endoplasmic reticulum (ER) activates the unfolded protein response (UPR). The ATF6 pathway is one of the three major pathways in vertebrates. Although ATF6, a transmembrane-type glycoprotein in the ER, functions as a UPR sensor/transducer, it is an unstable protein with a half-life of approximately 2 h and is constitutively subjected to the ER-associated

Neuronal cellular accumulation of amyloid beta peptide (Aβ) has been implicated in the pathogenesis of Alzheimer's disease (AD). Intracellular accumulation of Aβ42, a toxic form of Aβ, was observed as an early event in AD patients. However, its contribution and the cellular mechanism of cell death remained unclear. We herein revealed the mechanism by which Aβ42 incorporated into cells leads to cell

Histone chaperones are a group of histone-binding proteins that facilitate the assembly of nucleosomes, the fundamental structural units of chromatin in eukaryotes. In nucleosome assembly, deposition of a histone H3-H4 tetramer onto DNA is the first and critical step, which is mediated by the histone chaperones HIRA and CAF-1. HIRA and CAF-1 are reportedly involved in DNA replication independent (RI)

IRE1α plays an important role in the unfolded protein response (UPR), which is activated by the accumulation of unfolded proteins in the endoplasmic reticulum. 4μ8C, a well-known inhibitor of IRE1α RNase activity, is commonly used to analyze IRE1α function during ER stress in cultured mammalian cells. However, the off-target effects of 4μ8C remain elusive. Pancreatic β-cells synthesize a large amount