Article
Biochemistry & Molecular Biology
Lina Lorenzen, Dennis Frank, Carsten Schwan, Robert Grosse
Summary: FMNL2 is upregulated in several cancers and plays important roles in cell migration, invasion, cell-cell adhesion and filopodia formation. Using structured illumination microscopy, it was found that FMNL2 promotes rapid and highly dynamic filopodia formation in epithelial cells while remaining on the tip of the growing filopodia. This filopodia tip localization depends on its N-terminal myristoylation and serine 1072 phosphorylation within the diaphanous-autoregulatory domain (DAD) by protein kinase C (PKC) alpha.
Article
Multidisciplinary Sciences
John Xiao He Li, Vivian W. Tang, Kingsley A. Boateng, William M. Brieher
Summary: The study reveals that cadherin puncta are actually interdigitated actin microspikes generated by actin polymerization, rather than being formed by myosin pulling on cadherins. These interlocking microspikes expand the cell surface area and increase surface roughness to promote cell adhesion.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2021)
Article
Cell Biology
Eunhong Jang, Yeojin Moon, So Young Yoon, Joyce Anne R. Diaz, Miriam Lee, Naho Ko, Jongseo Park, Soo Hyun Eom, Changwook Lee, Youngsoo Jun
Summary: This study reveals that human atlastins are sufficient to induce membrane fusion when reconstituted into liposomes with a lipid composition mimicking that of the ER, including the weaker fusogenic activity of ATL1 predominantly expressed in neuronal cells. The addition of M1-spastin, a neuron-specific factor, significantly enhances ATL1-mediated liposome fusion. ATL2-1, an autoinhibited isoform of ATL2, is unable to support liposome fusion by itself, indicating the requirement of cellular factors for ATL2-1 to mediate ER fusion in vivo.
JOURNAL OF CELL BIOLOGY
(2023)
Article
Biochemistry & Molecular Biology
Micaela Boiero Sanders, Christopher P. Toret, Audrey Guillotin, Adrien Antkowiak, Thomas Vannier, Robert C. Robinson, Alphee Michelot
Summary: The use of different actin isoforms in eukaryotic cells and the molecular mechanisms of their segregation into distinct networks are poorly understood. By using yeast as a model, researchers found that the expression of heterologous actin causes significant reorganization of the actin cytoskeleton. However, the expression of two heterologous actin variants, each specialized in assembling a different network, can rescue cytoskeletal organization and increase resistance to external perturbation.
Article
Multidisciplinary Sciences
Yashar Bashirzadeh, Hossein Moghimianavval, Allen P. Liu
Summary: Cell shape changes during locomotion and cytokinesis are primarily driven by myosin-induced remodeling of cortical actin patterns. The architecture of actin networks, which largely determines the shape of the membrane, is influenced by passive crosslinkers such as alpha-actinin and fascin, as well as the actin nucleator Arp2/3 complex. By reconstituting actomyosin networks in cell-sized lipid bilayer vesicles, the study shows that the size of the vesicle and the concentrations of alpha-actinin and fascin can lead to the assembly of different actomyosin patterns, such as rings and aster-like structures.
Article
Cell Biology
Ke Zhang, Miaodan Huang, Ang Li, Jing Wen, Lingli Yan, Yunhao Li, Liman Guo, Kumaran Satyanarayanan Senthil, Yangyang Zhou, Guobing Chen, Yong Liu, Xiaofei Zhang, Xiaoli Yao, Dajiang Qin, Huanxing Su
Summary: In this study, DIAPH3 is identified as a scaffold protein that initiates liquid-liquid phase separation (LLPS) and forms cytosolic phase-separated DIAPH3 granules (D-granules) in response to stress. These D-granules sequester DIAPH3 and inhibit actin filament assembly in filopodia, serving as a regulatory hub for actin cytoskeletal remodeling during stress.
Article
Multidisciplinary Sciences
Ka Man Carmen Chan, Ashley L. Arthur, Johannes Morstein, Meiyan Jin, Abrar Bhat, Dorte Schlesinger, Sungmin Son, Donte A. Stevens, David G. Drubin, Daniel A. Fletcher
Summary: Fusion-associated small transmembrane (FAST) proteins are a diverse family of nonstructural viral proteins that drive cell-cell fusion, increasing viral spread and pathogenicity. Unlike viral fusogens with tall ectodomains, FAST proteins have short fusogenic ectodomains that cannot bridge the intermembrane gap between neighboring cells. This work suggests that localized mechanical pressure on the plasma membrane coupled to a membrane-disruptive ectodomain is sufficient to drive cell-cell fusion.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2021)
Article
Multidisciplinary Sciences
Feng-Ching Tsai, J. Michael Henderson, Zack Jarin, Elena Kremneva, Yosuke Senju, Julien Pernier, Oleg Mikhajlov, John Manzi, Konstantin Kogan, Christophe Le Clainche, Gregory A. Voth, Pekka Lappalainen, Patricia Bassereau
Summary: This study reveals the driving mechanism of filopodium initiation by the membrane curvature sensor IRSp53. Through controlled experiments in cellulo, in vitro, and in silico, it was found that IRSp53 self-assembles into clusters on membranes and recruits VASP to assemble actin filaments, leading to the generation of filopodia-like membrane protrusions. Additionally, IRSp53 can only enrich and trigger actin assembly in highly dynamic membrane regions. This research provides important clues for understanding the mechanism of filopodium initiation.
Article
Multidisciplinary Sciences
Samar Sayedyahossein, Jessica Smith, Elena Barnaeva, Zhigang Li, Jun Choe, Michael Ronzetti, Christopher Dextras, Xin Hu, Juan Marugan, Noel Southall, Bolormaa Baljinnyam, Louise Thines, Andy D. Tran, Marc Ferrer, David B. Sacks
Summary: Small molecules that inhibit the binding between Cdc42 and IQGAP1 have been identified, which could potentially lead to the development of chemotherapeutic agents.
SCIENTIFIC REPORTS
(2022)
Article
Cell Biology
Jens Ingo Hein, Jonas Scholz, Sarah Koerber, Thomas Kaufmann, Jan Faix
Summary: Besides Ena/VASP proteins, numerous other factors contribute to filopodia formation.
Article
Multidisciplinary Sciences
Sheng Yang, Yubo Tang, Yijun Liu, Abbigale J. Brown, Matthias Schaks, Bojian Ding, Daniel A. Kramer, Magdalena Mietkowska, Li Ding, Olga Alekhina, Daniel D. Billadeau, Saikat Chowdhury, Junmei Wang, Klemens Rottner, Baoyu Chen
Summary: This study reveals a new mechanism for WRC sensing Arf signaling and provides a mechanistic foundation for understanding how WRC-mediated actin polymerization links Arf and Rac signaling in cells.
Article
Cell Biology
Zhe Feng, Suho Lee, Bowen Jia, Tao Jian, Eunjoon Kim, Mingjie Zhang
Summary: The scaffold protein IRSp53 plays an important role in synapse development and synaptic plasticity. This study reveals that specific interactions between IRSp53 and its binding partners PSD-95 or Shank3 drive phase separation of complexes and promote synaptic enrichment of IRSp53 in mouse cortical neurons. The study also highlights the role of IRSp53 in actin filament formation and synaptic maturation. These findings provide mechanistic insights into the physiological roles of IRSp53 in synapse formation and function.
JOURNAL OF CELL BIOLOGY
(2022)
Article
Medicine, Research & Experimental
Lionel Chia, Bowen Wang, Jung-Hyun Kim, Li Z. Luo, Shuai Shuai, Iliana Herrera, Sophia Y. Chen, Liping Li, Lingling Xian, Tait Huso, Mohammad Heydarian, Karen Reddy, Woo Jung Sung, Shun Ishiyama, Gongbo Guo, Elizabeth Jaffee, Lei Zheng, Leslie M. Cope, Kathy Gabrielson, Laura Wood, Linda Resar
Summary: High mobility group A1 (HMGA1) chromatin regulators are upregulated in various tumors, particularly pancreatic ductal adenocarcinomas (PDACs), where they upregulate FGF19 expression and drive tumor progression and stroma formation. HMGA1 deficiency disrupts oncogenic properties and impairs tumor growth and formation of a desmoplastic stroma in mouse models of PDAC. Similarly, disrupting FGF19 via gene silencing or FGFR4 inhibition recapitulates the phenotypes observed with HMGA1 deficiency, highlighting FGF19 as a potential therapeutic target for a molecularly defined PDAC subtype.
JOURNAL OF CLINICAL INVESTIGATION
(2023)
Article
Cell Biology
Ruping Wang, Eylon Arbel, Dale D. Tang
Summary: This study demonstrates that smooth muscle myosin localizes at the leading edge of cells and orchestrates the recruitment of actin-regulatory proteins, promoting cell migration.
Article
Multidisciplinary Sciences
Anjali Kaushal, Julien Dorier, Bihan Wang, Giriram Mohana, Michael Taschner, Pascal Cousin, Patrice Waridel, Christian Iseli, Anastasiia Semenova, Simon Restrepo, Nicolas Guex, Erez Lieberman Aiden, Maria Cristina Gambetta
Summary: Boundaries in animal genomes play a crucial role in limiting regulatory cross-talk and guiding enhancers to target promoters. This study reveals that the formation and function of boundaries in flies are different from mammals. Unlike mammalian boundaries, most Drosophila boundaries form independently of CTCF and are recruited by Cp190. These boundaries are essential for early development and prevent regulatory cross-talk between specific gene loci, but are dispensable for long-range enhancer-promoter communication.
Article
Cell Biology
Iris K. Jarsch, Jonathan R. Gadsby, Annalisa Nuccitelli, Julia Mason, Hanae Shimo, Ludovic Pilloux, Bishara Marzook, Claire M. Mulvey, Ulrich Dobramysl, Charles R. Bradshaw, Kathryn S. Lilley, Richard D. Hayward, Tristan J. Vaughan, Claire L. Dobson, Jennifer L. Gallop
JOURNAL OF CELL BIOLOGY
(2020)
Article
Physics, Multidisciplinary
Ulrich Dobramysl, David Holcman
PHYSICAL REVIEW LETTERS
(2020)
Review
Biochemistry & Molecular Biology
Sachon Emmanuelle, Walrant Astrid, Sagan Sandrine, Cribier Sophie, Rodriguez Nicolas
Summary: Antimicrobial and cell-penetrating peptides have been extensively studied for over 60 years, initially separately and more recently in parallel. These studies have led to methodological advancements in observation techniques and membrane models, including the development of droplet interface bilayers, new fluorescence approaches, force measurements, and photolabelling techniques.
ARCHIVES OF BIOCHEMISTRY AND BIOPHYSICS
(2021)
Article
Cell Biology
Weronika Fic, Rebecca Bastock, Francesco Raimondi, Erinn Los, Yoshiko Inoue, Jennifer L. Gallop, Robert B. Russell, Daniel St Johnston
Summary: The study reveals that RhoGAP19D plays a crucial role in the polarity formation of follicular epithelium in fruit flies, by interacting with alpha-catenin to exclude active Cdc42 from the lateral domain and suppress epithelial invasion.
JOURNAL OF CELL BIOLOGY
(2021)
Review
Biochemical Research Methods
Astrid Walrant, Emmanuelle Sachon
Summary: Membranotropic peptides are a class of peptides that act at the level of cell membranes, and understanding their interactions with membrane binding partners is crucial. Photolabeling is a powerful method to study these interactions and provide a submolecular picture of the contacts between the peptides and membranes. This review provides an overview of photolabeling-based studies on the interactions of membranotropic peptides with membranes using photoreactive lipids or peptides.
BIOCONJUGATE CHEMISTRY
(2021)
Article
Cell & Tissue Engineering
Lucia Cordero-Espinoza, Anna M. Dowbaj, Timo N. Kohler, Bernhard Strauss, Olga Sarlidou, German Belenguer, Clare Pacini, Nuno P. Martins, Ross Dobie, John R. Wilson-Kanamori, Richard Butler, Nicole Prior, Palle Serup, Florian Jug, Neil C. Henderson, Florian Hollfelder, Meritxell Huch
Summary: This study demonstrates that a subpopulation of mouse periportal mesenchymal cells in organoid co-cultures exert dual control on epithelial proliferation, mediated by Notch signaling. Proliferation of ductal cells is influenced by the number of direct mesenchymal cell contacts, highlighting the critical role of cell-cell contacts in regulating cellular behaviors during regeneration.
Article
Biochemistry & Molecular Biology
Leila Bechtella, Edward Chalouhi, Paula Milan Rodriguez, Marine Cosset, Delphine Ravault, Francoise Illien, Sandrine Sagan, Ludovic Carlier, Olivier Lequin, Patrick F. J. Fuchs, Emmanuelle Sachon, Astrid Walrant
Summary: In this study, the role of the negatively charged lipid phosphatidylinositol-4,5-bisphosphate (PI(4,5)P-2) in the internalization of Penetratin was analyzed. The results showed that Penetratin has a strong affinity for PI(4,S)P-2 and PI(4,5)P-2 plays an important role in Penetratin internalization.
ACS CHEMICAL BIOLOGY
(2022)
Review
Biophysics
Sonia Khemaissa, Astrid Walrant, Sandrine Sagan
Summary: Trp is unique among the amino acids due to its involvement in various noncovalent interactions, including electrostatic, hydrophobic, pi-pi, pi-cation, pi-anion, and pi-ion pair interactions. This review focuses on the less explored role of Trp in membranotropic peptides, specifically its effects on CPP internalization and AMP activity, as well as its interactions with lipids, glycoconjugates, and extracellular matrix components. Understanding the physico-chemical properties and extensive interactions of Trp is essential for designing future membranotropic peptides with antimicrobial or cell-penetrating activity.
QUARTERLY REVIEWS OF BIOPHYSICS
(2022)
Article
Multidisciplinary Sciences
Khayam Javed, Jerome Jullien, Gaurav Agarwal, Nicola Lawrence, Richard Butler, Pantelis Savvas Ioannou, Farhat Nazir, J. B. Gurdon
Summary: The stability of gene expression in differentiated cells may be maintained through physical separation into liquid-liquid phase-separated condensates within the nucleus, which could help stabilize the active form of a gene in a nondividing cell and prevent malfunctions such as cancer.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2022)