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In vivo evidence for homeostatic regulation of ribosomal protein levels in Drosophila Cell Struct. Funct. (IF 1.5) Pub Date : 2024-02-16 Daiki Kitamura, Kiichiro Taniguchi, Mai Nakamura, Tatsushi Igaki
The ribosome is a molecular machine essential for protein synthesis, which is composed of approximately 80 different ribosomal proteins (Rps). Studies in yeast and cell culture systems have revealed that the intracellular level of Rps is finely regulated by negative feedback mechanisms or ubiquitin-proteasome system, which prevents over- or under-abundance of Rps in the cell. However, in vivo evidence
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Lysosomal membrane integrity in fibroblasts derived from patients with Gaucher disease Cell Struct. Funct. (IF 1.5) Pub Date : 2024-01-23 Asuka Hamamoto, Natsuki Kita, Siddabasave Gowda B. Gowda, Hiroyuki Takatsu, Kazuhisa Nakayama, Makoto Arita, Shu-Ping Hui, Hye-Won Shin
Gaucher disease (GD) is a recessively inherited lysosomal storage disorder characterized by a deficiency of lysosomal glucocerebrosidase (GBA1). This deficiency results in the accumulation of its substrate, glucosylceramide (GlcCer), within lysosomes. Here, we investigated lysosomal abnormalities in fibroblasts derived from patients with GD. It is noteworthy that the cellular distribution of lysosomes
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Coronin-1 promotes directional cell rearrangement in Drosophila wing epithelium Cell Struct. Funct. (IF 1.5) Pub Date : 2023-12-20 Keisuke Ikawa, Souta Hiro, Shu Kondo, Shizue Ohsawa, Kaoru Sugimura
Directional cell rearrangement is a critical process underlying correct tissue deformation during morphogenesis. Although the involvement of F-actin regulation in cell rearrangement has been established, the role and regulation of actin binding proteins (ABPs) in this process are not well understood. In this study, we investigated the function of Coronin-1, a WD-repeat actin-binding protein, in controlling
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Visual quantification of prostaglandin E2 discharge from a single cell Cell Struct. Funct. (IF 1.5) Pub Date : 2023-12-07 Tetsuya Watabe, Shinya Yamahira, Michiyuki Matsuda, Kenta Terai
Calcium transients drive cells to discharge prostaglandin E2 (PGE2). We visualized PGE2-induced protein kinase A (PKA) activation and quantitated PGE2 secreted from a single cell by combining fluorescence microscopy and a simulation model. For this purpose, we first prepared PGE2-producer cells that express either an optogenetic or a chemogenetic calcium channel stimulator: OptoSTIM1 or Gq-DREADD,
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Rab32 and Rab38 maintain bone homeostasis by regulating intracellular traffic in osteoclasts Cell Struct. Funct. (IF 1.5) Pub Date : 2023-11-17 Kanako Tokuda, Shiou-Ling Lu, Zidi Zhang, Yumiko Kato, Siyu Chen, Kazuya Noda, Katsutoshi Hirose, Yu Usami, Narikazu Uzawa, Shinya Murakami, Satoru Toyosawa, Mitsunori Fukuda, Ge-Hong Sun-Wada, Yoh Wada, Takeshi Noda
Osteoclasts play a crucial role in bone homeostasis by forming resorption pits on bone surfaces, resulting in bone resorption. The osteoclast expression of Rab38 protein is highly induced during differentiation from macrophages. Here we generated mice with double knockout (DKO) of Rab38 and its paralogue, Rab32, to investigate the roles of these proteins in osteoclasts. Bone marrow-derived macrophages
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Signal sequence-triage is activated by translocon obstruction sensed by an ER stress sensor IRE1α Cell Struct. Funct. (IF 1.5) Pub Date : 2023-11-03 Ashuei Sogawa, Ryota Komori, Kota Yanagitani, Miku Ohfurudono, Akio Tsuru, Koji Kadoi, Yukio Kimata, Hiderou Yoshida, Kenji Kohno
Secretory pathway proteins are cotranslationally translocated into the endoplasmic reticulum (ER) of metazoan cells through the protein channel, translocon. Given that there are far fewer translocons than ribosomes in a cell, it is essential that secretory protein-translating ribosomes only occupy translocons transiently. Therefore, if translocons are obstructed by ribosomes stalled or slowed in translational
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VAMP5 and distinct sets of cognate Q-SNAREs mediate exosome release Cell Struct. Funct. (IF 1.5) Pub Date : 2023-10-27 Takahide Matsui, Yuriko Sakamaki, Shu Hiragi, Mitsunori Fukuda
Small extracellular vesicles (sEVs) are largely classified into two types, plasma-membrane derived sEVs and endomembrane-derived sEVs. The latter type (referred to as exosomes herein) is originated from late endosomes or multivesicular bodies (MVBs). In order to release exosomes extracellularly, MVBs must fuse with the plasma membrane, not with lysosomes. In contrast to the mechanism responsible for
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Significance of the p38MAPK-CRP2 axis in myofibroblastic phenotypic transition Cell Struct. Funct. (IF 1.5) Pub Date : 2023-10-27 Ken’ichiro Hayashi, Reuben Jacob Labios, Tsuyoshi Morita, Atsushige Ashimori, Ren Aoki, Masanori Mikuni, Kazuhiro Kimura
We have recently demonstrated that a LIM domain protein, cysteine and glycine-rich protein 2 (CSRP2 [CRP2]), plays a vital role in the functional expression of myofibroblasts and cancer-associated fibroblasts. CRP2 binds directly to myocardin-related transcription factors (MRTF [MRTF-A or MRTF-B]) and serum response factor (SRF) to stabilize the MRTF/SRF/CArG-box complex, leading to the expression
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FilGAP, a GAP for Rac1, down-regulates invadopodia formation in breast cancer cells Cell Struct. Funct. (IF 1.5) Pub Date : 2023-09-23 Koji Saito, Sakino Ozawa, Yosuke Chiba, Ruri Takahashi, Ryoya Ogomori, Kojiro Mukai, Tomohiko Taguchi, Hiroyasu Hatakeyama, Yasutaka Ohta
Invadopodia are protrusive structures that mediate the extracellular matrix (ECM) degradation required for tumor invasion and metastasis. Rho small GTPases regulate invadopodia formation, but the molecular mechanisms of how Rho small GTPase activities are regulated at the invadopodia remain unclear. Here we have identified FilGAP, a GTPase-activating protein (GAP) for Rac1, as a negative regulator
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IC2 participates in the cooperative activation of outer arm dynein densely attached to microtubules Cell Struct. Funct. (IF 1.5) Pub Date : 2023-09-23 Yusuke Kondo, Tomoka Ogawa, Emiri Kanno, Masafumi Hirono, Takako Kato-Minoura, Ritsu Kamiya, Toshiki Yagi
Ciliary outer-arm dynein (OAD) consists of heavy chains (HCs), intermediate chains (ICs), and light chains (LCs), of which HCs are the motor proteins that produce force. Studies using the green alga Chlamydomonas have revealed that ICs and LCs form a complex (IC/LC tower) at the base of the OAD tail and play a crucial role in anchoring OAD to specific sites on the microtubule. In this study, we isolated
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Sphingomyelin metabolism underlies Ras excitability for efficient cell migration and chemotaxis Cell Struct. Funct. (IF 1.5) Pub Date : 2023-08-31 Da Young Shin, Hiroaki Takagi, Michio Hiroshima, Satomi Matsuoka, Masahiro Ueda
In eukaryotic motile cells, the active Ras (Ras-GTP)-enriched domain is generated in an asymmetric manner on the cell membrane through the excitable dynamics of an intracellular signaling network. This asymmetric Ras signaling regulates pseudopod formation for both spontaneous random migration and chemoattractant-induced directional migration. While membrane lipids, such as sphingomyelin and phosphatidylserine
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Two coral fluorescent proteins of distinct colors for sharp visualization of cell-cycle progression Cell Struct. Funct. (IF 1.5) Pub Date : 2023-07-29 Ryoko Ando, Asako Sakaue-Sawano, Keiko Shoda, Atsushi Miyawaki
We cloned and characterized two new coral fluorescent proteins: h2-3 and 1-41. h2-3 formed an obligate dimeric complex and exhibited bright green fluorescence. On the other hand, 1-41 formed a highly multimeric complex and exhibited dim red fluorescence. We engineered 1-41 into AzaleaB5, a practically useful red-emitting fluorescent protein for cellular labeling applications. We fused h2-3 and AzaleaB5
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Proteomic analysis of fatty liver induced by starvation of medaka fish larvae Cell Struct. Funct. (IF 1.5) Pub Date : 2023-07-19 Tomoyo Ikeda, Tokiro Ishikawa, Satoshi Ninagawa, Tetsuya Okada, Masaya Ono, Kazutoshi Mori
When medaka fish (Oryzias latipes) larvae are grown in the absence of exogenous nutrition, the liver becomes dark and positive to Oil Red O staining from 7 days post-hatch (dph). We determined the mechanism of this starvation-induced development of fatty liver by proteomic analysis using livers obtained from larvae grown in the presence or absence of 2% glucose at 5 dph. Results showed that changes
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Zebrafish imaging reveals hidden oncogenic–normal cell communication during primary tumorigenesis Cell Struct. Funct. (IF 1.5) Pub Date : 2023-06-16 Yukinari Haraoka, Mai Miyake, Tohru Ishitani
Oncogenic mutations drive tumorigenesis, and single cells with oncogenic mutations act as the tumor seeds that gradually evolve into fully transformed tumors. However, oncogenic cell behavior and communication with neighboring cells during primary tumorigenesis remain poorly understood. We used the zebrafish, a small vertebrate model suitable for in vivo cell biology, to address these issues. We describe
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Role of CRP2-MRTF interaction in functions of myofibroblasts Cell Struct. Funct. (IF 1.5) Pub Date : 2023-05-11 Ken’ichiro Hayashi, Shinri Horoiwa, Kotaro Mori, Hiroshi Miyata, Reuben Jacob Labios, Tsuyoshi Morita, Yuka Kobayashi, Chiemi Yamashiro, Fumiaki Higashijima, Takuya Yoshimoto, Kazuhiro Kimura, Yoshiaki Nakagawa
Inflammatory response induces phenotypic modulation of fibroblasts into myofibroblasts. Although transforming growth factor-βs (TGF-βs) evoke such transition, the details of the mechanism are still unknown. Here, we report that a LIM domain protein, cysteine-and glycine-rich protein 2 (CSRP2 [CRP2]) plays a vital role in the functional expression profile in myofibroblasts and cancer-associated fibroblasts
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Cell biology of protein–lipid conjugation Cell Struct. Funct. (IF 1.5) Pub Date : 2023-05-11 Jun-ichi Sakamaki, Noboru Mizushima
Protein–lipid conjugation is a widespread modification involved in many biological processes. Various lipids, including fatty acids, isoprenoids, sterols, glycosylphosphatidylinositol, sphingolipids, and phospholipids, are covalently linked with proteins. These modifications direct proteins to intracellular membranes through the hydrophobic nature of lipids. Some of these membrane-binding processes
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A conserved WXXE motif is an apical delivery determinant of ABC transporter C subfamily isoforms Cell Struct. Funct. (IF 1.5) Pub Date : 2023-03-09 Md Shajedul Haque, Yoshikazu Emi, Masao Sakaguchi
ATP-binding cassette transporter isoform C7 (ABCC7), also designated as cystic fibrosis transmembrane conductance regulator (CFTR), is exclusively targeted to the apical plasma membrane of polarized epithelial cells. Although the apical localization of ABCC7 in epithelia is crucial for the Cl– excretion into lumens, the mechanism regulating its apical localization is poorly understood. In the present
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A non-nucleotide agonist that binds covalently to cysteine residues of STING Cell Struct. Funct. (IF 1.5) Pub Date : 2023-02-16 Kentaro Matsumoto, Shenwei Ni, Hiroyuki Arai, Takashi Toyama, Yoshiro Saito, Takehiro Suzuki, Naoshi Dohmae, Kojiro Mukai, Tomohiko Taguchi
Stimulator of interferon genes (STING) is an ER-localized transmembrane protein and the receptor for 2',3'-cyclic guanosine monophosphate–adenosine monophosphate (cGAMP), which is a second messenger produced by cGAMP synthase (cGAS), a cytosolic double-stranded DNA sensor. The cGAS-STING pathway plays a critical role in the innate immune response to infection of a variety of DNA pathogens through the
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Enhancement of Vivid-based photo-activatable Gal4 transcription factor in mammalian cells Cell Struct. Funct. (IF 1.5) Pub Date : 2023-02-08 Shinji C. Nagasaki, Tomonori D. Fukuda, Mayumi Yamada, Yusuke III Suzuki, Ryo Kakutani, Adam T. Guy, Itaru Imayoshi
The Gal4/UAS system is a versatile tool to manipulate exogenous gene expression of cells spatially and temporally in many model organisms. Many variations of light-controllable Gal4/UAS system are now available, following the development of photo-activatable (PA) molecular switches and integration of these tools. However, many PA-Gal4 transcription factors have undesired background transcription activities
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Suppression of P-cadherin expression as a key regulatory element for embryonic stem cell stemness Cell Struct. Funct. (IF 1.5) Pub Date : 2023-02-08 Yuka Takeda, Shuji Matsuguchi, Sae Nozaki, Taisei Mihara, Junya Abe, Yohei Hirai
In embryonic stem (ES) cell colonies, a small subpopulation that changes cell shape and loses pluripotency often appears in two-dimensional (2D) cultures, even in the presence of a stemness factor. We have previously shown that membrane translocation of the syntaxin4, t-SNARE protein contributes to this phenomenon. Here, we show that ES cells in three-dimensional (3D) aggregates do not succumb to extruded
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Role of phosphatidylserine in the localization of cell surface membrane proteins in yeast Cell Struct. Funct. (IF 1.5) Pub Date : 2023-01-28 Ryutaro Kashikuma, Makoto Nagano, Hiroki Shimamura, Kouya Nukaga, Ikumi Katsumata, Junko Y. Toshima, Jiro Toshima
Phosphatidylserine (PS) is a constituent of the cell membrane, being especially abundant in the cytoplasmic leaflet, and plays important roles in a number of cellular functions, including the formation of cell polarity and intracellular vesicle transport. Several studies in mammalian cells have suggested the role of PS in retrograde membrane traffic through endosomes, but in yeast, where PS is localized
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Reconstitution of functional tight junctions with individual claudin subtypes in epithelial cells Cell Struct. Funct. (IF 1.5) Pub Date : 2023-01-20 Mikio Furuse, Daiki Nakatsu, Wendy Hempstock, Shiori Sugioka, Noriko Ishizuka, Kyoko Furuse, Taichi Sugawara, Yugo Fukazawa, Hisayoshi Hayashi
The claudin family of membrane proteins is responsible for the backbone structure and function of tight junctions (TJs), which regulate the paracellular permeability of epithelia. It is thought that each claudin subtype has its own unique function and the combination of expressed subtypes determines the permeability property of each epithelium. However, many issues remain unsolved in regard to claudin
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Quantitative 3D correlative light and electron microscopy of organelle association during autophagy Cell Struct. Funct. (IF 1.5) Pub Date : 2022-12-22 Satoru Takahashi, Chieko Saito, Ikuko Koyama-Honda, Noboru Mizushima
In macroautophagy, disk-shaped double-membrane structures called phagophores elongate to form cup-shaped structures, becoming autophagosomes upon closure. These autophagosomes then fuse with lysosomes to become autolysosomes and degrade engulfed material. Autophagosome formation is reported to involve other organelles, including the endoplasmic reticulum (ER) and mitochondria. Organelles are also taken
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PRL stimulates mitotic errors by suppressing kinetochore-localized activation of AMPK during mitosis Cell Struct. Funct. (IF 1.5) Pub Date : 2022-12-15 Kajung Ryu, Atsushi Yoshida, Yosuke Funato, Daisuke Yamazaki, Hiroaki Miki
Phosphatase of regenerating liver (PRL) is frequently overexpressed in various malignant cancers and is known to be a driver of malignancy. Here, we demonstrated that PRL overexpression causes mitotic errors that accompany spindle misorientation and aneuploidy, which are intimately associated with cancer progression. Mechanistic analyses of this phenomenon revealed dysregulation of the energy sensor
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Appropriate tension sensitivity of α-catenin ensures rounding morphogenesis of epithelial spheroids Cell Struct. Funct. (IF 1.5) Pub Date : 2022-07-27 Ryosuke Nishimura, Kagayaki Kato, Misako Saida, Yasuhiro Kamei, Masahiro Takeda, Hiromi Miyoshi, Yutaka Yamagata, Yu Amano, Shigenobu Yonemura
The adherens junction (AJ) is an actin filament-anchoring junction. It plays a central role in epithelial morphogenesis through cadherin-based recognition and adhesion among cells. The stability and plasticity of AJs are required for the morphogenesis. An actin-binding α-catenin is an essential component of the cadherin-catenin complex and functions as a tension transducer that changes its conformation
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A method for the generation of pseudovirus particles bearing SARS coronavirus spike protein in high yields Cell Struct. Funct. (IF 1.5) Pub Date : 2022-06-25 Yoichiro Fujioka, Sayaka Kashiwagi, Aiko Yoshida, Aya O. Satoh, Mari Fujioka, Maho Amano, Yohei Yamauchi, Yusuke Ohba
The ongoing severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic has threatened human health and the global economy. Development of additional vaccines and therapeutics is urgently required, but such development with live virus must be conducted with biosafety level 3 confinement. Pseudotyped viruses have been widely adopted for studies of virus entry and pharmaceutical development
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Munc13b stimulus-dependently accumulates on granuphilin-mediated, docked granules prior to fusion Cell Struct. Funct. (IF 1.5) Pub Date : 2022-05-21 Kouichi Mizuno, Tetsuro Izumi
The Rab27 effector granuphilin plays an indispensable role in stable docking of secretory granules to the plasma membrane by interacting with the complex of Munc18-1 and the fusion-incompetent, closed form of syntaxins-1~3. Although this process prevents spontaneous granule exocytosis, those docked granules actively fuse in parallel with other undocked granules after stimulation. Therefore, it is postulated
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Specific association of TBK1 with the trans-Golgi network following STING stimulation Cell Struct. Funct. (IF 1.5) Pub Date : 2022-03-08 Haruka Kemmoku, Yoshihiko Kuchitsu, Kojiro Mukai, Tomohiko Taguchi
Stimulator of interferon genes (STING) is essential for the type I interferon response induced by microbial DNA or self-DNA leaked from mitochondria/nuclei. In response to the emergence of such DNAs in the cytosol, STING relocates from the endoplasmic reticulum (ER) to the Golgi, and activates TANK-binding kinase 1 (TBK1), a cytosolic kinase essential for the activation of STING-dependent downstream
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Ubiquitin-like 3 as a new protein-sorting factor for small extracellular vesicles Cell Struct. Funct. (IF 1.5) Pub Date : 2022-02-23 Yusuke Takanashi, Tomoaki Kahyo, Sae Kamamoto, Hengsen Zhang, Bin Chen, Yashuang Ping, Kiyomichi Mizuno, Akikazu Kawase, Kei Koizumi, Masanori Satou, Kazuhito Funai, Norihiko Shiiya, Mitsutoshi Setou
Ubiquitin-like 3 (UBL3) is a well-conserved ubiquitin-like protein (UBL) in eukaryotes and regulates the ubiquitin cascade, but the significant roles of UBL3 in cellular processes remained unknown. Recently, UBL3 was elucidated to be a post-translational modification factor that promotes protein sorting to small extracellular vesicles (sEVs). Proteins sorted into sEVs have been studied as etiologies
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A Dual Promoter System to Monitor IFN-γ Signaling in vivo at Single-cell Resolution Cell Struct. Funct. (IF 1.5) Pub Date : 2021-12-22 Taisei Tanaka, Yoshinobu Konishi, Hiroshi Ichise, Shinya Tsukiji, Michiyuki Matsuda, Kenta Terai
IFN-γ secreted from immune cells exerts pleiotropic effects on tumor cells, including induction of immune checkpoint and antigen presentation, growth inhibition, and apoptosis induction. We combined a dual promoter system with an IFN-γ signaling responsive promoter to generate a reporter named the interferon sensing probe (ISP), which quantitates the response to IFN-γ by means of fluorescence and bioluminescence
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Visualization of DNA Replication in Single Chromosome by Stable Isotope Labeling Cell Struct. Funct. (IF 1.5) Pub Date : 2021-11-20 Kosuke Nagata, Ken-ichi Bajo, Hideyuki Mitomo, Ryosuke Fujita, Ryota Uehara, Kuniharu Ijiro, Hisayoshi Yurimoto
Among the inheritance of cellular components during cell division, deoxyribonucleic acid (DNA) and its condensate (chromosome) are conventionally visualized using chemical tag-labeled nucleotide analogs. However, associated mutagenesis with nucleotide analogs in the visualization of chromosomes is cause for concern. This study investigated the efficiency of using stable isotope labels in visualizing
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Nuclear RNA Regulation by XRN2 and XTBD Family Proteins Cell Struct. Funct. (IF 1.5) Pub Date : 2021-11-06 Ilkin Aygün, Takashi S. Miki
XRN2 is a 5'-to-3' exoribonuclease that is predominantly localized in the nucleus. By degrading or trimming various classes of RNA, XRN2 contributes to essential processes in gene expression such as transcription termination and ribosome biogenesis. Despite limited substrate specificity in vitro, XRN2 targets a specific subset of RNA by interacting with other proteins in cells. Here we review the functions
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In vivo Roles of Rab27 and Its Effectors in Exocytosis Cell Struct. Funct. (IF 1.5) Pub Date : 2021-11-06 Tetsuro Izumi
The monomeric GTPase Rab27 regulates exocytosis of a broad range of vesicles in multicellular organisms. Several effectors bind GTP-bound Rab27a and/or Rab27b on secretory vesicles to execute a series of exocytic steps, such as vesicle maturation, movement along microtubules, anchoring within the peripheral F-actin network, and tethering to the plasma membrane, via interactions with specific proteins
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Hrd1-dependent Degradation of the Unassembled PIGK Subunit of the GPI Transamidase Complex Cell Struct. Funct. (IF 1.5) Pub Date : 2021-09-03 Kohei Kawaguchi, Miki Yamamoto-Hino, Yoshiko Murakami, Taroh Kinoshita, Satoshi Goto
Glycosylphosphatidylinositol (GPI)-anchored proteins are post-transcriptionally modified with GPI and anchored to the plasma membrane. GPI is attached to nascent proteins in the endoplasmic reticulum by the GPI transamidase complex, which consists of PIGT, PIGK, GPAA1, PIGU, and PIGS. Of these, PIGK is a catalytic subunit that is unstable without PIGT. This study investigated the pathway by which unassembled
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Expression Patterns and Levels of All Tubulin Isotypes Analyzed in GFP Knock-In C. elegans Strains Cell Struct. Funct. (IF 1.5) Pub Date : 2021-06-30 Kei Nishida, Kenta Tsuchiya, Hiroyuki Obinata, Shizuka Onodera, Yu Honda, Yen-Cheng Lai, Nami Haruta, Asako Sugimoto
Most organisms have multiple α- and β-tubulin isotypes that likely contribute to the diversity of microtubule (MT) functions. To understand the functional differences of tubulin isotypes in Caenorhabditis elegans, which has nine α-tubulin isotypes and six β-tubulin isotypes, we systematically constructed null mutants and GFP-fusion strains for all tubulin isotypes with the CRISPR/Cas9 system and analyzed
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Multiple Ways for Stress Sensing and Regulation of the Endoplasmic Reticulum-stress Sensors Cell Struct. Funct. (IF 1.5) Pub Date : 2021-05-22 Quynh Giang Le, Yukio Kimata
Dysfunction of the endoplasmic reticulum (ER), so-called ER stress, is accompanied with accumulation of unfolded proteins in the ER. Eukaryotic cells commonly have an ER-located transmembrane protein, Ire1, which triggers cellular protective events against ER stress. In animal cells, PERK and ATF6 also initiate the ER-stress response. As a common strategy to control the activity of these ER-stress
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Mevalonate Pathway-mediated ER Homeostasis Is Required for Haploid Stability in Human Somatic Cells Cell Struct. Funct. (IF 1.5) Pub Date : 2021-02-19 Kan Yaguchi, Kimino Sato, Koya Yoshizawa, Daisuke Mikami, Kohei Yuyama, Yasuyuki Igarashi, Gabor Banhegyi, Eva Margittai, Ryota Uehara
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,
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Dispensability of Tubulin Acetylation for 15-protofilament Microtubule Formation in the Mammalian Cochlea Cell Struct. Funct. (IF 1.5) Pub Date : 2021-03-16 Justine Renauld, Nicolas Thelen, Odile Bartholomé, Brigitte Malgrange, Marc Thiry
The development of hearing in mammals requires the formation and maturation of a highly organized and specialized epithelium known as the organ of Corti. This epithelium contains two types of cells, the sensory cells, which are the true receptors of auditory information, and the surrounding supporting cells, which are composed of a highly developed cytoskeleton essential to the architecture of the
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Knock-in of Labeled Proteins into 5’UTR Enables Highly Efficient Generation of Stable Cell Lines Cell Struct. Funct. (IF 1.5) Pub Date : 2021-03-16 Faryal Ijaz, Koji Ikegami
Stable cell lines and animal models expressing tagged proteins are important tools for studying behaviors of cells and molecules. Several molecular biology technologies have been applied with varying degrees of success and efficiencies to establish cell lines expressing tagged proteins. Here we applied CRISPR/Cas9 for the knock-in of tagged proteins into the 5’UTR of the endogenous gene loci. With
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An Antiviral Drug Screening Platform with a FRET Biosensor for Measurement of Arenavirus Z Assembly Cell Struct. Funct. (IF 1.5) Pub Date : 2020-12-25 Tatsuaki Mizutani, Yusuke Ohba, Satoshi Mizuta, Jiro Yasuda, Shuzo Urata
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
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Prickle2 and Igsf9b Coordinately Regulate the Cytoarchitecture of the Axon Initial Segment. Cell Struct. Funct. (IF 1.5) Pub Date : 2020-09-01 Md Imrul Hasan Chowdhury,Tomoki Nishioka,Noriko Mishima,Toshihisa Ohtsuka,Kozo Kaibuchi,Daisuke Tsuboi
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
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Internalization of AMPA-type Glutamate Receptor in the MIN6 Pancreatic β-cell Line. Cell Struct. Funct. (IF 1.5) Pub Date : 2020-08-21 The Mon La,Hiroshi Yamada,Sayaka Seiriki,Shun-Ai Li,Kenshiro Fujise,Natsuho Katsumi,Tadashi Abe,Masami Watanabe,Kohji Takei
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
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Biliverdin Reductase-A Deficiency Brighten and Sensitize Biliverdin-binding Chromoproteins. Cell Struct. Funct. (IF 1.5) Pub Date : 2020-08-21 Kenju Kobachi,Sota Kuno,Shinya Sato,Kenta Sumiyama,Michiyuki Matsuda,Kenta Terai
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
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p18/Lamtor1-mTORC1 Signaling Controls Development of Mucin-producing Goblet Cells in the Intestine. Cell Struct. Funct. (IF 1.5) Pub Date : 2020-07-08 Shizuka Ito,Shigeyuki Nada,Daisuke Yamazaki,Tetsuya Kimura,Kentaro Kajiwara,Hiroaki Miki,Masato Okada
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
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Visualization of Procollagen IV Reveals ER-to-Golgi Transport by ERGIC-independent Carriers. Cell Struct. Funct. (IF 1.5) Pub Date : 2020-07-23 Yuto Matsui,Yukihiro Hirata,Ikuo Wada,Nobuko Hosokawa
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
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MON2 Guides Wntless Transport to the Golgi through Recycling Endosomes. Cell Struct. Funct. (IF 1.5) Pub Date : 2020-05-12 Shen-Bao Zhao,Neta Dean,Xiao-Dong Gao,Morihisa Fujita
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
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Roles of the Translation Initiation Factor eIF2α Phosphorylation in Cell Structure and Function. Cell Struct. Funct. (IF 1.5) Pub Date : 2020-04-29 Sung Hoon Back
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
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Centrosomal and Non-centrosomal Functions Emerged through Eliminating Centrosomes. Cell Struct. Funct. (IF 1.5) Pub Date : 2020-04-09 Yutaka Takeda,Kanako Kuroki,Takumi Chinen,Daiju Kitagawa
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
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Rab7B/42 is functionally involved in protein degradation on melanosomes in keratinocytes. Cell Struct. Funct. (IF 1.5) Pub Date : 2020-02-07 Soujiro Marubashi,Mitsunori Fukuda
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
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Hierarchical Development of Motile Polarity in Durotactic Cells Just Crossing an Elasticity Boundary. Cell Struct. Funct. (IF 1.5) Pub Date : 2019-12-27 Thasaneeya Kuboki,Hiroyuki Ebata,Tomoki Matsuda,Yoshiyuki Arai,Takeharu Nagai,Satoru Kidoaki
Cellular durotaxis has been extensively studied in the field of mechanobiology. In principle, asymmetric mechanical field of a stiffness gradient generates motile polarity in a cell, which is a driving factor of durotaxis. However, the actual process by which the motile polarity in durotaxis develops is still unclear. In this study, to clarify the details of the kinetics of the development of durotactic
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Development of a Rapid in vivo Assay to Evaluate the Efficacy of IRE1-specific Inhibitors of the Unfolded Protein Response Using Medaka Fish. Cell Struct. Funct. (IF 1.5) Pub Date : 2019-12-26 Byungseok Jin,Tokiro Ishikawa,Mai Taniguchi,Satoshi Ninagawa,Tetsuya Okada,Shigehide Kagaya,Kazutoshi Mori
Three types of transmembrane protein, IRE1α/IRE1β, PERK, and ATF6α/ATF6β, are expressed ubiquitously in vertebrates as transducers of the unfolded protein response (UPR), which maintains the homeostasis of the endoplasmic reticulum. IRE1 is highly conserved from yeast to mammals, and transmits a signal by a unique mechanism, namely splicing of mRNA encoding XBP1, the transcription factor downstream
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Reinvestigation of Disulfide-bonded Oligomeric Forms of the Unfolded Protein Response Transducer ATF6. Cell Struct. Funct. (IF 1.5) Pub Date : 2019-12-19 Hibiki Koba,Shengyu Jin,Nanami Imada,Tokiro Ishikawa,Satoshi Ninagawa,Tetsuya Okada,Tetsushi Sakuma,Takashi Yamamoto,Kazutoshi Mori
ATF6α is an endoplasmic reticulum (ER)-embedded transcription factor which is rapidly activated by ER stress, and a major regulator of ER chaperone levels in vertebrates. We previously suggested that ATF6α occurs as a monomer, dimer and oligomer in the unstressed ER of Chinese hamster ovary cells due to the presence of two evolutionarily conserved cysteine residues in its luminal region (C467 and C618)
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N-glycosylation of Rim21 at an Unconventional Site Fine-tunes Its Behavior in the Plasma Membrane. Cell Struct. Funct. (IF 1.5) Pub Date : 2019-11-30 Keisuke Obara,Tetsuya Kotani,Hitoshi Nakatogawa,Akio Kihara,Takumi Kamura
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
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Localization of BCR-ABL to Stress Granules Contributes to Its Oncogenic Function. Cell Struct. Funct. (IF 1.5) Pub Date : 2019-11-15 Sayaka Kashiwagi,Yoichiro Fujioka,Takeshi Kondo,Aya O Satoh,Aiko Yoshida,Mari Fujioka,Hitoshi Sasajima,Maho Amano,Takanori Teshima,Yusuke Ohba
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
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Folding Latency of Fluorescent Proteins Affects the Mitochondrial Localization of Fusion Proteins. Cell Struct. Funct. (IF 1.5) Pub Date : 2019-11-15 Sayaka Kashiwagi,Yoichiro Fujioka,Aya O Satoh,Aiko Yoshida,Mari Fujioka,Prabha Nepal,Atsushi Tsuzuki,Ozora Aoki,Sarad Paudel,Hitoshi Sasajima,Yusuke Ohba
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
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MGSE Regulates Crosstalk from the Mucin Pathway to the TFE3 Pathway of the Golgi Stress Response. Cell Struct. Funct. (IF 1.5) Pub Date : 2019-10-19 Mohamad Ikhwan Jamaludin,Sadao Wakabayashi,Mai Taniguchi,Kanae Sasaki,Ryota Komori,Hirotada Kawamura,Hayataka Takase,Miyu Sakamoto,Hiderou Yoshida
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
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Dispersion of Endoplasmic Reticulum-associated Compartments by 4-phenyl Butyric Acid in Yeast Cells. Cell Struct. Funct. (IF 1.5) Pub Date : 2019-10-17 Thanh Chi Mai,Yuki Ishiwata-Kimata,Quynh Giang Le,Hiroyuki Kido,Yukio Kimata
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
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Mutations in mxc Tumor-Suppressor Gene Induce Chromosome Instability in Drosophila Male Meiosis. Cell Struct. Funct. (IF 1.5) Pub Date : 2019-09-05 Karin Tanabe,Rie Awane,Tsuyoshi Shoda,Kanta Yamazoe,Yoshihiro H Inoue
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
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Identification of 15 New Bypassable Essential Genes of Fission Yeast. Cell Struct. Funct. (IF 1.5) Pub Date : 2019-08-31 Aoi Takeda,Shigeaki Saitoh,Hiroyuki Ohkura,Kenneth E Sawin,Gohta Goshima
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