Article
Biochemistry & Molecular Biology
Sabrina Chin, Taegun Kwon, Bibi Rafeiza Khan, J. Alan Sparks, Eileen L. Mallery, Daniel B. Szymanski, Elison B. Blancaflor
Summary: Root hairs are single-cell protrusions that help roots optimize nutrient and water absorption. Actin cytoskeleton and endomembrane systems are crucial for tip growth of root hairs. SPI, BRK1, and SCAR2 proteins play important roles in regulating root hair development in Arabidopsis, with SPI involved in maintaining tip growth and BRK1/SCAR2 specifying root hair emergence positions.
Article
Biochemistry & Molecular Biology
Shashi Prakash Singh, Peggy Paschke, Luke Tweedy, Robert H. Insall
Summary: PKB and SGK kinases play crucial roles in pseudopodia formation and cell motility, particularly in actin polymerization and recruitment of the Arp2/3 complex by the Scar/WAVE complex.
FRONTIERS IN MOLECULAR BIOSCIENCES
(2022)
Article
Biochemistry & Molecular Biology
Chen Liu, Andriani Mentzelopoulou, Amna Muhammad, Andriy Volkov, Dolf Weijers, Emilio Gutierrez-Beltran, Panagiotis N. Moschou
Summary: Cellular condensates known as processing bodies (PBs) in Arabidopsis thaliana were investigated using a proximity-biotinylation proteomics approach. The study revealed that PBs comprise networks that interface with membranes, and the conserved component DCP1 can localize to unique plasma membrane subdomains. A developmental module controlled by DCP1 and the actin-nucleating SCAR-WAVE complex was discovered at these membrane interfaces, which regulate cell shape. This study uncovers an unexpected function for a conserved condensate at unique membrane interfaces.
Article
Multidisciplinary Sciences
William J. Spencer, Nicholas F. Schneider, Tylor R. Lewis, Carson M. Castillo, Nikolai P. Skiba, Vadim Y. Arshavsky
Summary: The photoreceptor outer segment is a cilium filled with flat-tened disc membranes for light capture. The addition of new discs at the base of outer segments is driven by Arp2/3-mediated actin polymerization initiated by the pentameric WAVE complex. Knockout of WASF3, a subunit of the WAVE complex, disrupts actin polymerization and leads to disorganized membrane lamellae instead of a proper outer segment.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2023)
Article
Multidisciplinary Sciences
Bojian Ding, Heidy Y. Narvaez-Ortiz, Yuvraj Singh, Glen M. Hocky, Saikat Chowdhury, Brad J. Nolen
Summary: Arp2/3 complex nucleates branched actin filaments and provides pushing forces for cellular processes. This study reveals the contacts between Arp2/3 complex and the mother actin filament, suggesting that actin filaments stimulate subunit flattening for complex activation. However, limited contact between the bottom half of the complex and the mother filament may explain why actin filaments are required but insufficient to trigger nucleation during WASP-mediated activation.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2022)
Article
Developmental Biology
Nathalie Boure, Alexis Peaucelle, Magali Goussot, Bernard Adroher, Ludivine Soubigou-Taconnat, Nero Borrega, Eric Biot, Zakia Tariq, Marie-Laure Martin-Magniette, Veronique Pautot, Patrick Laufs, Nicolas Arnaud
Summary: Boundary domains play critical roles in plant development by regulating organ growth and morphogenesis through cell growth repression and modulation of cell wall properties. This study reveals the involvement of SPY and CUC2 in leaf boundary domain development, as they repress a common set of genes involved in cell wall loosening. Atomic force microscopy confirms that boundary domain cells have stiffer cell walls compared to marginal outgrowth.
Article
Multidisciplinary Sciences
Ah-Lai Law, Shamsinar Jalal, Tommy Pallett, Fuad Mosis, Ahmad Guni, Simon Brayford, Lawrence Yolland, Stefania Marcotti, James A. Levitt, Simon P. Poland, Maia Rowe-Sampson, Anett Jandke, Robert Kochl, Giordano Pula, Simon M. Ameer-Beg, Brian Marc Stramer, Matthias Krause
Summary: NHSL1 interacts with the Scar/WAVE complex to inhibit cell migration by potentially reducing Arp2/3 activity, leading to decreased F-actin density in lamellipodia and impairing protrusion stability.
NATURE COMMUNICATIONS
(2021)
Article
Multidisciplinary Sciences
Yanan Wang, Giovanni Chiappetta, Raphael Guerois, Yijun Liu, Stephane Romero, Daniel J. Boesch, Matthias Krause, Claire A. Dessalles, Avin Babataheri, Abdul I. Barakat, Baoyu Chen, Joelle Vinh, Anna Polesskaya, Alexis M. Gautreau
Summary: The RAC1-WAVE-Arp2/3 signaling pathway generates branched actin networks that power lamellipodium protrusion of migrating cells. PPP2R1A is a protein that associates with the WAVE complex subunit ABI1 when RAC1 is activated and branched actin generation is blocked. PPP2R1A interacts with the WAVE Shell Complex at the lamellipodial edge and is required for migration persistence and RAC1-dependent actin polymerization. Mutations in PPP2R1A impair WAVE Shell Complex binding and migration regulation, suggesting its essential role in cell migration.
NATURE COMMUNICATIONS
(2023)
Article
Biochemistry & Molecular Biology
Diane Pelzer, Ludmilla de Plater, Peta Bradbury, Adrien Eichmuller, Anne Bourdais, Guillaume Halet, Jean-Leon Maitre
Summary: Cell fragmentation is a common phenomenon in human preimplantation embryos and is associated with poor prognosis during assisted reproductive technology procedures. This study uses light sheet microscopy imaging to reveal that inefficient chromosome separation due to spindle defects, caused by dysfunctional molecular motors Myo1c or dynein, leads to cell fragmentation during mitosis. The extended exposure of the cell cortex to chromosomes triggers actomyosin contractility and pinches off cell fragments, similar to the process observed during meiosis. This study uncovers the mechanisms underlying cell fragmentation in preimplantation embryos and provides insight into the regulation of mitosis during the maternal-zygotic transition.
Article
Biochemistry & Molecular Biology
Luyan Cao, Foad Ghasemi, Michael Way, Antoine Jegou, Guillaume Romet-Lemonne
Summary: Activation of the Arp2/3 complex by actin nucleation-promoting factors leads to the formation of branching actin filaments, while direct nucleation of linear actin filaments is induced by SPIN90-Arp2/3. Interestingly, the VCA motifs of certain proteins destabilize existing branches and linear filament ends. However, branch stabilizer cortactin and destabilizer GMF have similar effects on SPIN90-activated Arp2/3. These findings highlight the importance of understanding the similarities and differences between the two mechanisms in regulating actin cytoskeleton dynamics, as well as the differential responses of branched and linear filaments to aging and mechanical stress.
Review
Cell Biology
Emmanuel Martin, Magali Suzanne
Summary: This review discusses the role of the actin nucleation complex Arp2/3 in epithelial tissue, including its influence on cell-cell cooperation and tissue morphogenesis. It plays a significant role in regulating cell-cell adhesion, intracellular trafficking, and protrusion formation.
FRONTIERS IN CELL AND DEVELOPMENTAL BIOLOGY
(2022)
Review
Biochemistry & Molecular Biology
Kyung Ah Han, Jaewon Ko
Summary: Brain disorders: Multiple roles of protein complex need further exploration。 Extensive research is needed to understand how the components of a critical protein complex at synapses influence the properties of neural circuits. Dysfunction of the WRC components are associated with various brain disorders。
EXPERIMENTAL AND MOLECULAR MEDICINE
(2023)
Article
Plant Sciences
Kotomi Kikukawa, Kazuki Yoshimura, Akira Watanabe, Takumi Higaki
Summary: A new silver-nano-ink coating method was proposed for time-lapse imaging and quantification of morphological changes in epidermal cells of growing Arabidopsis thaliana cotyledons, providing a quantitative evaluation of cell growth and morphogenesis. This method allows for non-destructive phenotyping of plant surface structures over time and is easier to use compared to traditional methods that require fluorescent dye labeling or transformation with marker gene constructs and expensive microscopes.
FRONTIERS IN PLANT SCIENCE
(2021)
Review
Biochemistry & Molecular Biology
Daniel T. Zuch, Siamsa M. Doyle, Mateusz Majda, Richard S. Smith, Stephanie Robert, Keiko U. Torii
Summary: The epidermis, as the outermost layer of plants, plays a critical role in plant-environment interactions. Differentiation of specialized epidermal cell types occurs during leaf development, but how these cells coordinate as a unit is not well understood. This review highlights the regulatory mechanisms governing the fate, differentiation, and positioning of these specialized cell types, emphasizing their shared developmental origins, fate flexibility, and hormonal controls, while also discussing computational modeling approaches to integrate mechanical properties of individual epidermal cell types and tissue properties.
Article
Cell Biology
Shuting Zhang, Dimitrios Vavylonis
Summary: The nucleation of actin filament branches by the Arp2/3 complex involves activation through nucleation promotion factors (NPFs), recruitment of actin monomers, and binding of the complex to the side of actin filaments. Our molecular dynamics simulations using a coarse-grained model revealed stable configurations of the Arp2/3 complex with actin monomers and the activating VCA domain of the NPF Wiskott-Aldrich syndrome protein, supporting prior structural studies and providing insight into mechanisms proposed in previous studies.
FRONTIERS IN CELL AND DEVELOPMENTAL BIOLOGY
(2023)