A5102840423- Lipid Membrane Structure and Behavior
- Cellular transport and secretion
- Sphingolipid Metabolism and Signaling
- Endoplasmic Reticulum Stress and Disease
- Fungal and yeast genetics research
- Plant Reproductive Biology
- Photosynthetic Processes and Mechanisms
- Erythrocyte Function and Pathophysiology
- Cholesterol and Lipid Metabolism
- Lipid metabolism and biosynthesis
- Caveolin-1 and cellular processes
- Pancreatic function and diabetes
- Calcium signaling and nucleotide metabolism
- Laser Applications in Dentistry and Medicine
- Antimicrobial Peptides and Activities
- interferon and immune responses
- Viral Infections and Outbreaks Research
- Protein Kinase Regulation and GTPase Signaling
- Exercise and Physiological Responses
- Diet, Metabolism, and Disease
- Cancer therapeutics and mechanisms
- Autophagy in Disease and Therapy
- Heat shock proteins research
- Plant Molecular Biology Research
- Phytase and its Applications
Hokkaido University
2003-2025
Tohoku University
2025
RIKEN
2013-2020
National Institutes of Health
2020
Yale University
2020
Harvard University
2020
Rockefeller University
2020
Brigham and Women's Hospital
2020
Federation of American Societies for Experimental Biology
2020
Kyorin University
2016
Abstract Stimulator of interferon genes (STING) is critical for the type I response to pathogen- or self-derived DNA in cytosol. STING may function as a scaffold activate TANK-binding kinase 1 (TBK1), but direct cellular evidence remains lacking. Here we show, using single-molecule imaging with enhanced time resolutions down 5 ms, that becomes clustered at trans-Golgi network (about 20 molecules per cluster). The clustering requires palmitoylation and Golgi lipid order defined by...
P4-ATPases translocate aminophospholipids, such as phosphatidylserine (PS), to the cytosolic leaflet of membranes. PS is highly enriched in recycling endosomes (REs) and essential for endosomal membrane traffic. Here, we show that flipping by an RE-localized P4-ATPase required recruitment fission protein EHD1. Depletion ATP8A1 impaired asymmetric transbilayer distribution REs, dissociated EHD1 from generated aberrant tubules appear resistant fission. did not localization cells defective...
During endocytic vesicle formation, distinct subdomains along the membrane invagination are specified by different proteins, which bend and drive scission. Bin-Amphiphysin-Rvs (BAR) Fer-CIP4 homology-BAR (F-BAR) proteins can induce curvature have been suggested to facilitate Two F-BAR Syp1 Bzz1, found at budding yeast sites. arrives early but departs from site before formation of deep invaginations Using genetic, spatiotemporal, ultrastructural analyses, we demonstrate that heterodimeric BAR...
Sphingomyelin (SM) is a major sphingolipid in mammalian cells and reported to form specific lipid domains together with cholesterol. However, methods examine the membrane distribution of SM are limited. We demonstrated model membranes that fluorescent protein conjugates 2 SM-binding toxins, lysenin (Lys) equinatoxin II (EqtII), recognize different distributions SM; Lys exclusively binds clustered SM, whereas EqtII preferentially dispersed SM. Freeze-fracture immunoelectron microscopy showed...
Type 4 P-type ATPases (flippases) are implicated in the generation of phospholipid asymmetry membranes by inward translocation phospholipids. In budding yeast, DRS2/DNF family members Lem3p-Dnf1p/Dnf2p and Cdc50p-Drs2p putative flippases that localized, respectively, to plasma membrane endosomal/trans-Golgi network (TGN) compartments. Herein, we identified a protein kinase gene, FPK1, as mutation exhibited synthetic lethality with cdc50Delta mutation. The domain Fpk1p exhibits high homology...
BAR domains are protein modules that bind to membranes and promote membrane curvature. One type of domain, the N-BAR contains an additional N-terminal amphipathic helix, which contributes membrane-binding bending activities. The only known N-BAR-domain proteins in budding yeast Saccharomyces cerevisiae, Rvs161 Rvs167, required for endocytosis. We have explored mechanism function endocytosis process using a combined biochemical genetic approach. show purified Rvs161-Rvs167 complex binds...
A mixture of sphingomyelin (SM) and cholesterol (Chol) exhibits a characteristic lipid raft domain the cell membranes that provides platform to which various signal molecules as well virus bacterial proteins are recruited. Several capable specifically binding either SM or Chol have been reported. However, selectively bind SM/Chol mixtures less characterized. In our screening for liposomes, we identified novel ortholog Pleurotus ostreatus, pleurotolysin (Ply)A, from extract edible mushroom...
Ceramide phosphoethanolamine (CPE), a sphingomyelin analog, is major sphingolipid in invertebrates and parasites, whereas only trace amounts are present mammalian cells. In this study, mushroom-derived proteins of the aegerolysin family—pleurotolysin A2 (PlyA2; K(D) = 12 nM), ostreolysin (Oly; 1.3 erylysin A (EryA; nM)—strongly associated with CPE/cholesterol (Chol)-containing membranes, their low affinity to sphingomyelin/Chol precluded establishment binding kinetics. Binding specificity...
We identified a novel, nontoxic mushroom protein that specifically binds to complex of sphingomyelin (SM), major sphingolipid in mammalian cells, and cholesterol (Chol). The purified protein, termed nakanori, labeled cell surface domains an SM- Chol-dependent manner decorated specific lipid colocalized with inner leaflet small GTPase H-Ras, but not K-Ras. use nakanori as lipid-domain–specific probe revealed altered distribution dynamics SM/Chol on the Niemann-Pick type C fibro-blasts,...
Proteins of Chlamydia pneumoniae immunodominant in humans were characterized with the sera 13 patients who not likely to have been exposed C. trachomatis or psittaci. The serological responses among these similar on a qualitative basis, but some differences found quantitatively. However, infected differed markedly from those two and psittaci mice that transtracheally pneumoniae. Among proteins pneumoniae, 40-kDa major outer membrane protein was genus specific 53-, 46-, 43-kDa species their...
Phospholipid flippase (type 4 P-type ATPase) plays a major role in the generation of phospholipid asymmetry eukaryotic cell membranes. Loss Lem3p-Dnf1/2p flippases leads to exposure phosphatidylserine (PS) and phosphatidylethanolamine (PE) on surface yeast, resulting sensitivity PS- or PE-binding peptides. We isolated Sfk1p, conserved membrane protein TMEM150/FRAG1/DRAM family, as multicopy suppressor this sensitivity. Overexpression SFK1 decreased PS/PE lem3Δ mutant cells. Consistent with...
Sterols are important lipid components of the plasma membrane (PM) in eukaryotic cells, but it is unknown how PM retains sterols at a high concentration. Phospholipids asymmetrically distributed PM, and phospholipid flippases play an role generating this asymmetry. Here, we provide evidence that essential for retaining ergosterol yeast. A mutant three flippases, Dnf1-Lem3, Dnf2-Lem3, Dnf3-Crf1, protein, Sfk1, showed severe growth defect. We recently identified Sfk1 as protein involved The...
Significance Lipid membrane curvature plays important roles in various physiological phenomena. Using darkfield microscopy, we performed nonbiased screening of a protein that induces deformations nonlabeled liposomes. We identified phospholipase Cβ1 (PLCβ1), which tubulation the phosphatidylethanolamine and phosphatidylserine-containing membranes. The characteristic C-terminal sequence PLCβ1, but not conserved inositol phospholipid-binding pleckstrin homology (PH) domain or catalytic domains...
Ykt6 is a conserved SNARE protein involved in multiple membrane trafficking pathways, including intra-Golgi transport and autophagic fusion. We previously demonstrated that mammalian uniquely modified with farnesyl geranylgeranyl groups at two C-terminal cysteines through the sequential action of farnesyltransferase (FT) geranylgeranyltransferase type 3 (GGT3). Although these are strictly all eukaryotes, evolutionary conservation double prenylation remains unclear, as budding yeast appears...
Specific changes in membrane lipid composition are implicated actin cytoskeletal organization, vesicle formation, and control of cell polarity. Cdc50p, a protein the endosomal/trans-Golgi network compartments, is noncatalytic subunit Drs2p, which translocation phospholipids across bilayers. We found that cdc50Delta mutation synthetically lethal with mutations affecting late steps ergosterol synthesis (erg2 to erg6). Defects polarity organization were observed erg3Delta mutant. In particular,...
VAMP7 is a SNARE protein that mediates specific membrane fusions in intracellular trafficking and was recently reported to regulate autophagosome formation. However, its function pancreatic β-cells largely unknown. To elucidate the physiological role of β-cells, we generated β-cell-specific knockout (Vamp7(flox/Y);Cre) mice. deletion impaired glucose-stimulated ATP production insulin secretion, though not localized granules. VAMP7-deficient showed defective formation reduced mitochondrial...
During adhesion, cells develop filopodia to facilitate the attachment extracellular matrix. The small guanosine triphosphate (GTP)-binding protein, Cdc42, plays a central role in formation of filopodia. It has been reported that Cdc42 activity is regulated by cholesterol (Chol). We examined Chol distribution using Chol-binding domain 4 (D4) fragment bacterial toxin, perfringolysin O senses high membrane concentration Chol. Our results indicate fluorescent D4 was enriched at tip outer leaflet...
Abstract Epithelial cells provide cell-cell adhesion that is essential to maintain the integrity of multicellular organisms. cell-characterizing proteins, such as epithelial junctional proteins and transcription factors are well defined. However, role lipids in characterization remains poorly understood. Here we show phospholipid phosphatidylinositol (4,5)-bisphosphate [PI(4,5)P 2 ] enriched plasma membrane (PM) cells. lose their characteristics upon depletion PM PI(4,5)P , synthesis results...
Abstract Sphingomyelin (SM) is a major sphingolipid in mammalian cells. SM enriched the extracellular leaflet of plasma membrane (PM). Besides this localization, recent electron microscopic and biochemical studies suggest presence cytosolic PM. In present study, we generated non-toxic SM-binding variant (NT-EqtII) based on equinatoxin-II (EqtII) from sea anemone Actinia equina , examined dynamics living cell PMs. NT-EqtII with two point mutations (Leu26Ala Pro81Ala) had essentially same...
ABSTRACT Membrane phase separation to form micron-scale domains of lipids and proteins occurs in artificial membranes; however, a similar large-scale has not been reported the plasma membrane living cells. We show here that stable protein-depleted region is generated yeast mutants lacking phosphatidylserine at high temperatures. named this ‘void zone’. Transmembrane certain peripheral phospholipids are excluded from void zone. The zone rich ergosterol, requires ergosterol sphingolipids for...