Related Experiment Video
Updated: Aug 8, 2025
08:57
Myosin-Specific Adaptations of In vitro Fluorescence Microscopy-Based Motility Assays
Published on: February 4, 2021
6.0K
Non-muscle myosin 2 filaments are processive in cells
Eric A Vitriol1, Melissa A Quintanilla2, Joseph J Tidei2
1Department of Neuroscience and Regenerative Medicine, Augusta University, Augusta, GA.
Biorxiv : the Preprint Server for Biology
|March 3, 2023
Summary
Non-muscle myosin 2 (NM2) exhibits processive movement within cells, not just in vitro. This cellular property of NM2 broadens its known functions in cell biology and directed transport.
Area of Science:
- Cell Biology
- Molecular Motor Function
- Cytoskeletal Dynamics
Background:
- Directed transport relies on processive cytoskeletal motors.
- Myosin 2 motors are typically non-processive, engaging oppositely oriented actin filaments for contraction.
- Recent in vitro studies suggested myosin 2 filaments can be processive.
Approach:
- Established non-muscle myosin 2 (NM2) processivity as a cellular property in CAD cells.
- Observed NM2 movements on bundled actin in cellular protrusions.
- Compared in vivo processive velocities with in vitro measurements and analyzed NM2 isoforms (NM2A, NM2B).
Key Points:
- Processive NM2 runs occur against lamellipodia retrograde flow in filamentous form.
- Anterograde movement is observed in the absence of actin dynamics.
- NM2A exhibits slightly faster processivity than NM2B.
- Processive NM2 movements are not cell-specific, observed in fibroblasts as well.
Conclusions:
- Non-muscle myosin 2 (NM2) demonstrates processivity as an intrinsic cellular property.
- This finding expands the known roles of NM2 in cellular functions.
- Ubiquitous motor protein NM2 contributes to a wider range of biological processes.
Related Concept Videos
01:18Role of Myosin in Cell Migration
2.4K
Myosins are multimeric motor proteins involved in various cellular processes such as migration, adhesion, and proliferation. Myosin II is the most common type in animal cells, which binds and cross-links actin filaments.
Myosin II is a hexamer comprising two heavy chains with globular heads and coiled-coil tails, two regulatory light chains, and two essential light chains. The ATPase sites on the myosin heads hydrolyze ATP, and the released phosphate generates the force for contraction....
Myosin II is a hexamer comprising two heavy chains with globular heads and coiled-coil tails, two regulatory light chains, and two essential light chains. The ATPase sites on the myosin heads hydrolyze ATP, and the released phosphate generates the force for contraction....
2.4K
01:10The Role of Actin and Myosin in Non-muscle Cells
3.6K
Actin and myosin or actomyosin filaments also play a significant role in cells other than those involved in muscle contraction (which occurs within the sarcomere of muscle cells). The mechanism of non-muscle cell contractile bundles was first observed in Dictyostelium and Acanthamoeba. In non-muscle cells, two bundles are commonly found: stress fibers and actomyosin adherence belts. These contractile bundles are smaller and less organized than the ones found in muscle cells. They are held...
3.6K
01:15Overview of Myosin Structure and Function
4.5K
Myosins are a family of molecular motor proteins, first identified in the skeletal muscles, where they are responsible for muscle contraction. Along with their role in muscle contraction, these proteins also play a role in the intracellular transport of molecules and vesicles. There are twenty-four classes of myosins based on their domain sequence and organization. Of the twenty-four, six classes (Myosin I, Myosin II, Myosin V, Myosin VI, Myosin VII, and Myosin X) have been well...
4.5K
01:39Mechanism of Filopodia Formation
2.4K
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...
2.4K
01:43The Movement of Organelles and Vesicles
4.6K
In eukaryotic cells, cytoskeletal filaments such as actin, microtubules, and intermediate filaments form a mesh-like cytoskeletal network. These filaments serve as tracks for transporting cellular cargo. Specialized motor proteins use the chemical energy stored in adenosine triphosphate (ATP) for this transport. During interphase, microtubules are polarized, with the plus-end towards the cell periphery and the minus-end towards the cell center. Two microtubule-associated motor proteins,...
4.6K
01:13Actin Polymerization and Cell Motility
5.3K
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....
5.3K