Related Experiment Video
Updated: Jul 12, 2026
05:50
Measuring Cell-Edge Protrusion Dynamics during Spreading using Live-Cell Microscopy
Published on: November 1, 2021
N-WASP deficiency reveals distinct pathways for cell surface projections and microbial actin-based motility
S B Snapper1, F Takeshima, I Antón
1Center for Blood Research, 200 Longwood Avenue, Boston, Massachusetts 02115, USA. ssnapper@hms.harvard.edu
Nature Cell Biology
|October 5, 2001
Summary
The study inactivated the N-WASP gene in mice, revealing its essential role in embryonic development and pathogen motility. N-WASP is crucial for embryogenesis and the movement of certain bacteria and viruses, but not general actin structure formation.
Area of Science:
- Cell Biology
- Developmental Biology
- Microbiology
Background:
- The Wiskott-Aldrich syndrome protein (WASP) family regulates actin cytoskeleton dynamics.
- N-WASP is involved in cell motility and pathogen movement.
Purpose of the Study:
- To investigate the function of N-WASP in murine embryogenesis and pathogen motility.
- To determine the necessity of N-WASP for actin-based structures.
Main Methods:
- Homologous recombination was used to inactivate the murine N-WASP gene.
- N-WASP-deficient embryos and fibroblasts were analyzed.
- Motility of intracellular pathogens (Shigella, vaccinia virus, Listeria) was assessed.
Main Results:
- N-WASP-deficient embryos exhibited developmental delay and died before embryonic day 12.
- N-WASP was essential for Shigella and vaccinia virus motility, but not Listeria.
- N-WASP-deficient fibroblasts could still form lamellipodia and filopodia.
Conclusions:
- N-WASP plays a critical and non-redundant role in mouse embryonic development.
- N-WASP is indispensable for the actin-based motility of specific pathogens.
- N-WASP is not required for general actin-containing structure formation.
Related Concept Videos
01:09Cell Migration
Cell migration, the process by which cells move from one location to another, is essential for the proper development and viability of organisms throughout their life. When cells are not able to migrate properly to their ordained locations, various disorders may occur. For example, disruption in cell migration causes chronic inflammatory diseases such as arthritis.
01:29Cytoskeletal Proteins in Bacteria
Bacterial cells were initially considered simple, randomly organized structures lacking a cytoskeleton. However, the discovery of cytoskeleton homologs in bacteria led to the change of this opinion. Bacterial cytoskeletal filaments regulate the cell shape, cell polarity, cell division, and partitioning of plasmids during cell division. It was later discovered that bacterial cytoskeletal proteins, mainly actin and tubulin homologs, are diverse compared to their eukaryotic counterparts. On the...
01:13Actin Polymerization and Cell Motility
Actin is a family of globular proteins that are highly abundant in eukaryotic cells. It makes up approximately 1-5% of total cell protein concentration. Actin monomers polymerize to form a complex network of polarized filaments, the actin cytoskeleton, that plays a crucial role in many cellular processes, including cell motility, division, endocytosis, and metastasis of cancer cells.
Actin cytoskeleton dynamics can produce pushing, pulling, and resistance forces that help the cell to migrate.
Actin cytoskeleton dynamics can produce pushing, pulling, and resistance forces that help the cell to migrate.
01:39Mechanism of Filopodia Formation
Filopodia are thin, actin-rich cellular protrusions that play an important role in many fundamental cellular functions. They vary in their occurrence, length, and positioning in different cell types, suggesting their diverse roles.
Their main function is to guide migrating cells during normal tissue morphogenesis or cancer metastasis by recognizing and making initial contacts with the extracellular matrix. However, they can also act as stationary cell anchors or help to establish communication...
Their main function is to guide migrating cells during normal tissue morphogenesis or cancer metastasis by recognizing and making initial contacts with the extracellular matrix. However, they can also act as stationary cell anchors or help to establish communication...
01:31Mechanism of Lamellipodia Formation
Cells migrating in response to external stimuli form lamellipodia, which are thin membrane protrusions supported by a mesh of linked, branched, or unbranched actin filaments. These actin filaments interact with myosin motor proteins, creating the dynamic actomyosin complex within the cytoskeleton. Contractility, or the ability to generate contractile stress, is inherent to the actomyosin complex. It helps cells detect the stiffness of the surrounding ECM and exert contractile force for...
01:28Fimbriae, Pili, and Axial Filaments
Fimbriae and pili are specialized bacterial surface structures that play pivotal roles in adhesion, genetic exchange, and motility. Composed primarily of pilin protein, these hairlike appendages are crucial for bacterial survival and pathogenicity in various environments.Fimbriae: Adhesion and PathogenicityFimbriae are fine, filamentous structures measuring 2–10 nanometers in diameter and are densely distributed on the bacterial cell surface. They facilitate bacterial adhesion to abiotic...