Read by QxMD icon Read


Dongjie Zhou, Yun-Jung Choi, Jin-Hoi Kim
Tubastatin A (Tub-A), a highly selective histone deacetylase 6 (HDAC6) inhibitor, has been widely used as a cytotoxic anticancer agent, or for the treatment of patients with asthma. However, the potential toxicity of Tub-A on oocyte maturation and asymmetric division is still unclear. Therefore, the present study was designed to examine the effect and potential regulatory role of Tub-A on the meiotic maturation of oocytes. We observed that Tub-A treatment induced an increased level of the acetylation of α-tubulin, and a failure of spindle migration and actin cap formation...
August 15, 2017: Scientific Reports
Hiroaki Kubota, Makito Miyazaki, Taisaku Ogawa, Togo Shimozawa, Kazuhiko Kinosita, Shin'ichi Ishiwata
Formins are force-sensing proteins that regulate actin polymerization dynamics. Here, we applied stretching tension to individual actin filaments under the regulation of formin mDia1 to investigate the mechanical responses in actin polymerization dynamics. We found that the elongation of an actin filament was accelerated to a greater degree by stretching tension for ADP-G-actin than that for ATP-G-actin. An apparent decrease in the critical concentration of G-actin was observed, especially in ADP-G-actin. These results on two types of G-actin were reproduced by a simple kinetic model, assuming the rapid equilibrium between pre- and posttranslocated states of the formin homology domain two dimer...
July 25, 2017: Biophysical Journal
Flora De Conto, Alessandra Fazzi, Sergey V Razin, Maria Cristina Arcangeletti, Maria Cristina Medici, Silvana Belletti, Carlo Chezzi, Adriana Calderaro
Viruses depend on cellular machinery to efficiently replicate. The host cytoskeleton is one of the first cellular systems hijacked by viruses in order to ensure their intracellular transport and promote the development of infection. Our previous results demonstrated that stable microfilaments and microtubules interfered with human influenza A/NWS/33 virus (H1N1) infection in semi-permissive LLC-MK2 cells. Although formins play a key role in cytoskeletal remodelling, few studies addressed a possible role of these proteins in development of viral infection...
July 25, 2017: Molecular and Cellular Biochemistry
Ravi Bharadwaj, Ranjana Arya, M Shahid Mansuri, Sudha Bhattacharya, Alok Bhattacharya
The protozoan parasite Entamoeba histolytica causes amoebiasis, a major public health problem in developing countries. Motility of E. histolytica is important for its pathogenesis. Blebbing is an essential process contributing to cellular motility in many systems. In mammalian cells, formation of plasma membrane blebs is regulated by Rho-GTPases through its effectors, such as Rho kinase, mDia1, and acto-myosin proteins. In this study, we have illuminated the role of EhRho1 in bleb formation and motility of E...
May 6, 2017: Cellular Microbiology
Buer Sen, Gunes Uzer, Rebekah M Samsonraj, Zhihui Xie, Cody McGrath, Maya Styner, Amel Dudakovic, Andre J van Wijnen, Janet Rubin
Actin structure contributes to physiologic events within the nucleus to control mesenchymal stromal cell (MSC) differentiation. Continuous cytochalasin D (Cyto D) disruption of the MSC actin cytoskeleton leads to osteogenic or adipogenic differentiation, both requiring mass transfer of actin into the nucleus. Cyto D remains extranuclear, thus intranuclear actin polymerization is potentiated by actin transfer: we asked whether actin structure affects differentiation. We show that secondary actin filament branching via the Arp2/3 complex is required for osteogenesis and that preventing actin branching stimulates adipogenesis, as shown by expression profiling of osteogenic and adipogenic biomarkers and unbiased RNA-seq analysis...
June 2017: Stem Cells
Bipul R Acharya, Selwin K Wu, Zi Zhao Lieu, Robert G Parton, Stephan W Grill, Alexander D Bershadsky, Guillermo A Gomez, Alpha S Yap
Formins are a diverse class of actin regulators that influence filament dynamics and organization. Several formins have been identified at epithelial adherens junctions, but their functional impact remains incompletely understood. Here, we tested the hypothesis that formins might affect epithelial interactions through junctional contractility. We focused on mDia1, which was recruited to the zonula adherens (ZA) of established Caco-2 monolayers in response to E-cadherin and RhoA. mDia1 was necessary for contractility at the ZA, measured by assays that include a FRET-based sensor that reports molecular-level tension across αE-catenin...
March 21, 2017: Cell Reports
Tolga Soykan, Natalie Kaempf, Takeshi Sakaba, Dennis Vollweiter, Felix Goerdeler, Dmytro Puchkov, Natalia L Kononenko, Volker Haucke
Neurotransmission is based on the exocytic fusion of synaptic vesicles (SVs) followed by endocytic membrane retrieval and the reformation of SVs. Recent data suggest that at physiological temperature SVs are internalized via clathrin-independent ultrafast endocytosis (UFE) within hundreds of milliseconds, while other studies have postulated a key role for clathrin-mediated endocytosis (CME) of SV proteins on a timescale of seconds to tens of seconds. Here we demonstrate using cultured hippocampal neurons as a model that at physiological temperature SV endocytosis occurs on several timescales from less than a second to several seconds, yet, is largely independent of clathrin...
February 22, 2017: Neuron
Megha Vaman Rao, Ronen Zaidel-Bar
Cadherin-mediated cell-cell adhesion is required for epithelial tissue integrity in homeostasis, during development, and in tissue repair. E-cadherin stability depends on F-actin, but the mechanisms regulating actin polymerization at cell-cell junctions remain poorly understood. Here we investigated a role for formin-mediated actin polymerization at cell-cell junctions. We identify mDia1 and Fmnl3 as major factors enhancing actin polymerization and stabilizing E-cadherin at epithelial junctions. Fmnl3 localizes to adherens junctions downstream of Src and Cdc42 and its depletion leads to a reduction in F-actin and E-cadherin at junctions and a weakening of cell-cell adhesion...
September 15, 2016: Molecular Biology of the Cell
Daniela Leyton-Puig, Katarzyna M Kedziora, Tadamoto Isogai, Bram van den Broek, Kees Jalink, Metello Innocenti
Super-resolution microscopy (SRM) allows precise localization of proteins in cellular organelles and structures, including the actin cytoskeleton. Yet sample preparation protocols for SRM are rather anecdotal and still being optimized. Thus, SRM-based imaging of the actin cytoskeleton and associated proteins often remains challenging and poorly reproducible. Here, we show that proper paraformaldehyde (PFA)-based sample preparation preserves the architecture of the actin cytoskeleton almost as faithfully as gold-standard glutaraldehyde fixation...
2016: Biology Open
Jessica L Henty-Ridilla, Aneliya Rankova, Julian A Eskin, Katelyn Kenny, Bruce L Goode
Microtubules (MTs) govern actin network remodeling in a wide range of biological processes, yet the mechanisms underlying this cytoskeletal cross-talk have remained obscure. We used single-molecule fluorescence microscopy to show that the MT plus-end-associated protein CLIP-170 binds tightly to formins to accelerate actin filament elongation. Furthermore, we observed mDia1 dimers and CLIP-170 dimers cotracking growing filament ends for several minutes. CLIP-170-mDia1 complexes promoted actin polymerization ~18 times faster than free-barbed-end growth while simultaneously enhancing protection from capping proteins...
May 20, 2016: Science
Daehwan Kim, Sangmyung Rhee
Mammalian diaphanous‑related formin 1 (mDia1) was initially identified as a Rho GTPase effector involved in the progression of various diseases, including types of cancer. However, the precise underlying molecular mechanism of mDia1‑mediated cancer cell invasion remains to be elucidated. In the present study, mDia1 expression was demonstrated to be upregulated in tissues from a number of cancer types, including kidney, prostate, and breast cancer using immunohistochemical analysis. Forced expression of a constitutively active (CA) form of mDia1 induces invasion, as measured by Transwell invasion assay, of MDA‑MB‑231 cells, which is a highly invasive breast cancer cell line, and this effect was markedly impaired by matrix metalloproteinase (MMP)‑2 silencing...
July 2016: Molecular Medicine Reports
Francesca Bartolini, Laura Andres-Delgado, Xiaoyi Qu, Sara Nik, Nagendran Ramalingam, Lenor Kremer, Miguel A Alonso, Gregg G Gundersen
Multiple formins regulate microtubule (MT) arrays, but whether they function individually or in a common pathway is unknown. Lysophosphatidic acid (LPA) stimulates the formation of stabilized detyrosinated MTs (Glu MTs) in NIH3T3 fibroblasts through RhoA and the formin mDia1. Here we show that another formin, INF2, is necessary for mDia1-mediated induction of Glu MTs and regulation of MT dynamics and that mDia1 can be bypassed by activating INF2. INF2 localized to MTs after LPA treatment in an mDia1-dependent manner, suggesting that mDia1 regulates INF2...
June 1, 2016: Molecular Biology of the Cell
Pascale Monzo, Yuk Kien Chong, Charlotte Guetta-Terrier, Anitha Krishnasamy, Sharvari R Sathe, Evelyn K F Yim, Wai Hoe Ng, Beng Ti Ang, Carol Tang, Benoit Ladoux, Nils C Gauthier, Michael P Sheetz
Glioblastomas are extremely aggressive brain tumors with highly invasive properties. Brain linear tracks such as blood vessel walls constitute their main invasive routes. Here we analyze rat C6 and patient-derived glioma cell motility in vitro using micropatterned linear tracks to mimic blood vessels. On laminin-coated tracks (3-10 μm), these cells used an efficient saltatory mode of migration similar to their in vivo migration. This saltatory migration was also observed on larger tracks (50-400 μm in width) at high cell densities...
April 15, 2016: Molecular Biology of the Cell
Megan A Ziske, Krista M Pettee, MaNada Khaing, Kaitlin Rubinic, Kathryn M Eisenmann
Due to a lack of effective screening or prevention protocol for epithelial ovarian cancer (EOC), there is a critical unmet need to develop therapeutic interventions for EOC treatment. EOC metastasis is unique. Initial dissemination is not primarily hematogenous, yet is facilitated through shedding of primary tumor cells into the peritoneal fluid and accumulating ascites. Increasingly, isolated patient spheroids point to a clinical role for spheroids in EOC metastasis. EOC spheroids are highly invasive structures that disseminate upon peritoneal mesothelium, and visceral tissues including liver and omentum...
March 25, 2016: Biochemical and Biophysical Research Communications
Daehwan Kim, Jangho Jung, Eunae You, Panseon Ko, Somi Oh, Sangmyung Rhee
Mammalian diaphanous-related formin 1 (mDia1) expression has been linked with progression of malignant cancers in various tissues. However, the precise molecular mechanism underlying mDia1-mediated invasion in cancer cells has not been fully elucidated. In this study, we found that mDia1 is upregulated in invasive breast cancer cells. Knockdown of mDia1 in invasive breast cancer profoundly reduced invasive activity by controlling cellular localization of membrane type 1-matrix metalloproteinase (MT1-MMP) through interaction with microtubule tracks...
April 5, 2016: Oncotarget
Romina P Salinas, Rodolfo M Ortiz Flores, Jesús S Distel, Milton O Aguilera, María I Colombo, Walter Berón
The GTPases belonging to the Rho family control the actin cytoskeleton rearrangements needed for particle internalization during phagocytosis. ROCK and mDia1 are downstream effectors of RhoA, a GTPase involved in that process. Coxiella burnetii, the etiologic agent of Q fever, is internalized by the host´s cells in an actin-dependent manner. Nevertheless, the molecular mechanism involved in this process has been poorly characterized. This work analyzes the role of different GTPases of the Rho family and some downstream effectors in the internalization of C...
2015: PloS One
Pablo Vargas, Paolo Maiuri, Marine Bretou, Pablo J Sáez, Paolo Pierobon, Mathieu Maurin, Mélanie Chabaud, Danielle Lankar, Dorian Obino, Emmanuel Terriac, Matthew Raab, Hawa-Racine Thiam, Thomas Brocker, Susan M Kitchen-Goosen, Arthur S Alberts, Praveen Sunareni, Sheng Xia, Rong Li, Raphael Voituriez, Matthieu Piel, Ana-Maria Lennon-Duménil
Dendritic cell (DC) migration in peripheral tissues serves two main functions: antigen sampling by immature DCs, and chemokine-guided migration towards lymphatic vessels (LVs) on maturation. These migratory events determine the efficiency of the adaptive immune response. Their regulation by the core cell locomotion machinery has not been determined. Here, we show that the migration of immature DCs depends on two main actin pools: a RhoA-mDia1-dependent actin pool located at their rear, which facilitates forward locomotion; and a Cdc42-Arp2/3-dependent actin pool present at their front, which limits migration but promotes antigen capture...
January 2016: Nature Cell Biology
L Cheng, J Xu, Y Y Qian, H Y Pan, H Yang, M Y Shao, R Cheng, T Hu
AIM: To investigate the effects of mammalian homologue of Drosophila diaphanous-1(mDia1) and Rho-associated coiled-coil-containing protein kinase (ROCK) on the migration and adhesion of dental pulp cells (DPCs). METHODOLOGY: Lysophosphatidic acid (LPA) was used to activate Rho signalling. mDia1 and ROCK were inhibited by short interfering RNA and the specific inhibitor, Y-27632, respectively. The migration of DPCs was assessed using the transwell migration assay and scratch test...
January 2017: International Endodontic Journal
Jeffrey P Bombardier, Julian A Eskin, Richa Jaiswal, Ivan R Corrêa, Ming-Qun Xu, Bruce L Goode, Jeff Gelles
Precise control of actin filament length is essential to many cellular processes. Formins processively elongate filaments, whereas capping protein (CP) binds to barbed ends and arrests polymerization. While genetic and biochemical evidence has indicated that these two proteins function antagonistically, the mechanism underlying the antagonism has remained unresolved. Here we use multi-wavelength single-molecule fluorescence microscopy to observe the fully reversible formation of a long-lived 'decision complex' in which a CP dimer and a dimer of the formin mDia1 simultaneously bind the barbed end...
November 13, 2015: Nature Communications
Shashank Shekhar, Mikael Kerleau, Sonja Kühn, Julien Pernier, Guillaume Romet-Lemonne, Antoine Jégou, Marie-France Carlier
Proteins targeting actin filament barbed ends play a pivotal role in motile processes. While formins enhance filament assembly, capping protein (CP) blocks polymerization. On their own, they both bind barbed ends with high affinity and very slow dissociation. Their barbed-end binding is thought to be mutually exclusive. CP has recently been shown to be present in filopodia and controls their morphology and dynamics. Here we explore how CP and formins may functionally coregulate filament barbed-end assembly...
2015: Nature Communications
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"