GO:0031032 actomyosin structure organization: Mechanism, Genes and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0031032 actomyosin structure organization describes the assembly, arrangement, and disassembly of cytoskeletal structures that contain both actin and myosin, including myosin filament organization.
• Core molecular players include actin, non-muscle myosin II, myosin chaperones, calponin, and Rho-family GTPase effectors such as Rac1.
• Actomyosin remodeling drives cell shape change, stress fiber formation, cytokinesis, migration, and tissue morphogenesis.
• The FXR1 network acts as a signaling scaffold that coordinates actomyosin remodeling in cells.
• Dysregulated actomyosin organization contributes to cancer cell invasion, kidney repair defects, and immune cell migration disorders.
• CRISPR knockout, point mutation, knock-in, and overexpression models enable causal dissection of actomyosin genes in disease and development.
Description
Actomyosin structure organization (GO:0031032) is the biological process that builds, arranges, and dismantles cytoskeletal structures containing both actin and myosin or paramyosin. This process is fundamental to how cells generate force, change shape, and move through their environment. Unlike static cytoskeletal descriptions, actomyosin organization is dynamic and tightly regulated, involving myosin motor activity, actin filament turnover, and accessory proteins that crosslink or stabilize the network. Researchers study GO:0031032 because it sits at the intersection of cell mechanics, developmental morphogenesis, and human disease. For example, ascidian notochord elongation depends on actomyosin-driven cell intercalation and shape change, while slow integrin-dependent migration of mast cells requires organized actomyosin networks. In the kidney, Rac1 mechanically couples cell morphology to mitotic entry during collecting duct repair, a process dependent on actomyosin organization. The FXR1 network has been shown to act as a signaling scaffold for actomyosin remodeling, linking RNA-binding proteins to cytoskeletal dynamics. Myosin chaperones ensure proper folding and assembly of myosin motors, which are essential for actomyosin function. Calponin modulates actin-myosin interactions and is a key regulator of smooth muscle and non-muscle actomyosin. Myosin XVIII is an unconventional myosin with roles in actomyosin organization and cell architecture. Actin stress fibers are prominent actomyosin structures that transmit forces and sense mechanical cues. Thus, GO:0031032 is a central node for understanding mechanobiology, tissue repair, and cancer progression.
actomyosin structure organization At A Glance
| GO ID | GO:0031032 |
|---|---|
| GO term | actomyosin structure organization |
| Ontology | biological_process |
| Synonym | actomyosin organization; actomyosin structure organisation; actomyosin structure organization and biogenesis |
| Major function | Assembly, arrangement, and disassembly of cytoskeletal structures containing actin and myosin or paramyosin |
| Cellular location | Cytoskeleton, actin stress fibers, contractile ring, cell cortex |
| Key molecular players | Actin, non-muscle myosin II, myosin chaperones, calponin, Rac1, FXR1 |
| Associated processes | Cell migration, cytokinesis, morphogenesis, tissue repair, mechanotransduction |
| Research relevance | Cancer invasion, kidney repair, immune cell migration, developmental elongation |
What Is GO:0031032?
GO:0031032 actomyosin structure organization is defined as a cellular process that results in the assembly, arrangement of constituent parts, or disassembly of cytoskeletal structures containing both actin and myosin or paramyosin, where myosin may be organized into filaments. In simpler terms, it is the set of events that builds, positions, and breaks down the actin-myosin machinery inside cells. This includes the formation of stress fibers, contractile rings, and other actomyosin bundles that generate mechanical force. The process is not limited to muscle cells; it operates in non-muscle cells during migration, division, and shape change. Myosin chaperones and accessory proteins such as calponin participate in the proper assembly and regulation of these structures. The term also encompasses the disassembly of actomyosin structures, which is critical for dynamic cellular remodeling.
Why Is actomyosin structure organization Important in Cell Biology?
Actomyosin structure organization is essential for virtually every dynamic cell behavior, from cytokinesis and migration to tissue morphogenesis and repair. Because it integrates mechanical force with biochemical signaling, defects in this process underlie a wide range of human pathologies, including cancer metastasis, kidney injury, and immune disorders. Understanding GO:0031032 therefore provides mechanistic insight into both normal physiology and disease, and it offers targets for therapeutic intervention.
• Controls cell shape changes during embryonic development, such as ascidian notochord elongation.
• Enables slow integrin-dependent migration of tissue-resident mast cells.
• Promotes kidney collecting duct repair by coupling cell morphology to mitotic entry via Rac1.
• Forms actin stress fibers that transmit mechanical forces and regulate cell adhesion.
• Involves myosin chaperones that ensure proper myosin folding and assembly.
• Is modulated by calponin, which regulates actin-myosin interactions.
• Includes unconventional myosins such as myosin XVIII with roles in cell architecture.
• Is coordinated by RNA-binding protein networks like FXR1 that scaffold actomyosin remodeling.
• Dysregulation contributes to cancer cell invasion and metastasis.
• Provides mechanistic targets for regenerative medicine and cancer therapy.
What Happens During actomyosin structure organization?
Initiation and nucleation of actin filaments
In simple terms: The cell starts building actin filaments that will form the backbone of actomyosin structures.
Actomyosin structure organization begins with the nucleation and elongation of actin filaments, which serve as tracks for myosin motors. Actin stress fibers are assembled from actin filaments bundled by crosslinking proteins, and their formation is often initiated at focal adhesions in response to mechanical or chemical signals. The FXR1 network can act as a signaling scaffold that coordinates the early steps of actomyosin remodeling. Calponin binds to actin and modulates filament stability and myosin ATPase activity, influencing the initiation of contractile structures.
Myosin assembly and chaperone-assisted folding
In simple terms: Myosin motors must be properly folded and assembled into filaments to generate force.
Myosin chaperones are essential for the folding and assembly of myosin heavy chains into functional motors. These chaperones ensure that myosin can form filaments and interact with actin to produce contractile force. Myosin XVIII, an unconventional myosin, contributes to actomyosin organization in specific cellular contexts, including cell architecture and adhesion. The assembly of myosin into filaments is a regulated step that determines the contractile capacity of actomyosin structures.
Crosslinking and bundle formation
In simple terms: Accessory proteins tie actin and myosin together into organized bundles like stress fibers.
Actin stress fibers are contractile bundles of actin filaments and myosin II that are crosslinked by proteins such as alpha-actinin and fascin. These bundles transmit mechanical forces between the cell and its environment and are dynamically reorganized during migration and adhesion. Calponin can inhibit or modulate the crosslinking and contractility of actomyosin bundles in smooth muscle and non-muscle cells. The FXR1 network may influence bundle formation by scaffolding signaling molecules that regulate crosslinkers.
Contraction and force generation
In simple terms: Myosin pulls on actin to generate the force that changes cell shape or moves the cell.
Myosin motors hydrolyze ATP to move along actin filaments, generating contractile force that drives cell shape changes and migration. In ascidian notochord elongation, actomyosin contraction drives cell intercalation and tissue elongation. Slow integrin-dependent migration of mast cells requires actomyosin contraction to organize networks of tissue-resident cells. Rac1 promotes kidney collecting duct repair by mechanically coupling cell morphology to mitotic entry through actomyosin contractility.
Disassembly and remodeling
In simple terms: Actomyosin structures are taken apart and rebuilt to allow dynamic cell behaviors.
Disassembly of actomyosin structures is as important as assembly, enabling cells to change shape, divide, and migrate. The FXR1 network acts as a signaling scaffold that can coordinate both assembly and disassembly of actomyosin during remodeling. Stress fibers are dynamically turned over, with disassembly occurring at specific cellular sites to permit new adhesion and migration cycles. Myosin chaperones may also participate in quality control during disassembly and recycling of myosin.
Key Genes Involved in GO:0031032 actomyosin structure organization
The following genes and proteins are central to actomyosin structure organization, based on published literature.
| Gene | Major Role | Research Relevance |
|---|---|---|
| ACTB | Actin filament backbone | Core structural component of stress fibers and contractile rings |
| MYH9 | Non-muscle myosin II heavy chain | Force generation and contractility |
| MYH10 | Non-muscle myosin IIB | Cytokinesis and cell shape |
| MYH14 | Non-muscle myosin IIC | Actomyosin organization in specific tissues |
| CNN1 | Calponin, actin-binding regulator | Modulates actin-myosin interaction |
| CNN2 | Calponin 2 | Regulates smooth muscle and non-muscle actomyosin |
| CNN3 | Calponin 3 | Actin cytoskeleton regulation |
| MYO18A | Unconventional myosin XVIII | Cell architecture and actomyosin organization |
| MYO18B | Unconventional myosin XVIIIB | Actomyosin and cell motility |
| FXR1 | RNA-binding protein scaffold | Signaling scaffold for actomyosin remodeling |
| RAC1 | Rho-family GTPase | Couples cell morphology to mitotic entry via actomyosin |
| ITGB1 | Integrin beta 1 | Integrin-dependent migration and actomyosin organization |
| HSPB1 | Small heat shock protein | Myosin chaperone network component |
| DNAJB4 | Hsp40 co-chaperone | Myosin folding and assembly |
| UNC45A | Myosin chaperone | Myosin maturation and actomyosin function |
| UNC45B | Myosin chaperone | Myosin folding in muscle and non-muscle cells |
| ACTN1 | Alpha-actinin, crosslinker | Stress fiber bundling and stability |
How Is actomyosin structure organization Regulated?
Actomyosin structure organization is regulated by Rho-family GTPases such as Rac1, which couples cell morphology to mitotic entry and repair processes. Integrin signaling provides external mechanical cues that organize actomyosin networks during slow migration of mast cells. The FXR1 network acts as a signaling scaffold that coordinates actomyosin remodeling, linking RNA-binding proteins to cytoskeletal effectors. Myosin chaperones regulate the availability of properly folded myosin for assembly. Calponin modulates actin-myosin interactions and can inhibit contractility in a phosphorylation-dependent manner.
actomyosin structure organization and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| RAC1 | Kidney collecting duct repair | Knockout or point mutation in kidney epithelial cells |
| FXR1 | Cancer cell signaling and actomyosin remodeling | Knockout or overexpression in cancer cell lines |
| MYH9 | Actomyosin contractility in cancer and immune cells | Knockout or knock-in of contractility mutants |
| ITGB1 | Mast cell migration and tissue residency | Knockout in mast cell models |
| CNN1 | Smooth muscle and non-muscle actomyosin regulation | Overexpression or knockout in fibroblasts |
Cancer and metastasis
Actomyosin structure organization is hijacked in cancer cells to promote invasion and metastasis. Stress fibers and contractile bundles enable cancer cells to remodel the extracellular matrix and migrate. The FXR1 network, which scaffolds actomyosin remodeling, has been implicated in cancer cell signaling. Targeting actomyosin regulators is a potential therapeutic strategy.
Kidney injury and repair
Rac1 promotes kidney collecting duct repair by mechanically coupling cell morphology to mitotic entry, a process dependent on actomyosin organization. Defects in this pathway can impair tissue regeneration after injury.
Immune cell migration disorders
Slow integrin-dependent migration of tissue-resident mast cells requires organized actomyosin networks. Disruption of actomyosin organization can lead to defective immune cell positioning and function.
Developmental morphogenesis defects
Ascidian notochord elongation depends on actomyosin-driven cell intercalation and shape change. Perturbations in actomyosin organization can cause developmental malformations.
From actomyosin structure organization-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does loss of RAC1 impair kidney repair? | RAC1 knockout in kidney epithelial cells |
| How does FXR1 scaffold actomyosin remodeling? | FXR1 knockout or tagged knock-in in cancer cells |
| What is the role of myosin chaperones in actomyosin assembly? | UNC45A/B knockout or point mutation |
| How does calponin regulate actin-myosin interaction? | CNN1 overexpression or knockout |
| Does myosin XVIII contribute to cell architecture? | MYO18A/B knockout or knock-in |
| How do integrins organize mast cell actomyosin networks? | ITGB1 knockout in mast cells |
How to Study the actomyosin structure organization Process
| Method | What It Measures | Typical Application |
|---|---|---|
| Live-cell imaging | Actin and myosin dynamics | Stress fiber assembly and disassembly |
| Proteomics | Protein composition and modifications | Identifying actomyosin components |
| CRISPR knockout | Loss-of-function effects | Testing gene necessity for actomyosin organization |
| CRISPR knock-in | Tagged or mutant protein expression | Visualizing or perturbing specific actomyosin proteins |
| Traction force microscopy | Cellular force generation | Mechanobiology of actomyosin |
| RNA-seq | Transcriptional changes | Pathway analysis after actomyosin perturbation |
| Co-immunoprecipitation | Protein-protein interactions | Identifying actomyosin complexes |
| FRAP | Protein turnover dynamics | Actin and myosin exchange rates |
Live-cell imaging of actomyosin dynamics
Live-cell fluorescence microscopy of actin and myosin reporters allows real-time visualization of actomyosin assembly and disassembly. This method is essential for studying stress fiber dynamics and contractile ring formation.
Proteomics and interactomics
Mass spectrometry-based proteomics can identify components of actomyosin structures and their post-translational modifications. Interactomics reveals how scaffolds like FXR1 coordinate actomyosin remodeling.
Genetic perturbation with CRISPR
CRISPR knockout, point mutation, and knock-in models enable causal testing of actomyosin gene function in cells and organisms. These approaches are critical for linking specific residues or domains to actomyosin organization.
Mechanical measurements
Traction force microscopy and atomic force microscopy measure forces generated by actomyosin structures. These techniques quantify how actomyosin organization translates into mechanical output.
How CRISPR Can Be Used to Study GO:0031032 actomyosin structure organization
Knockout
CRISPR knockout of actomyosin genes such as RAC1, MYH9, or FXR1 allows researchers to test their requirement for actomyosin structure organization. Knockout models reveal loss-of-function phenotypes in cell migration, cytokinesis, and tissue repair.
Point Mutation
Point mutations can be introduced into actomyosin genes to dissect domain-specific functions, such as myosin motor activity or calponin actin-binding. These models help distinguish between structural and regulatory roles.
Knock-in
Knock-in of fluorescent tags or epitope tags into endogenous actomyosin genes enables real-time visualization and biochemical isolation of actomyosin complexes. Tagged knock-in models are valuable for studying dynamic remodeling.
Overexpression
Overexpression of actomyosin regulators such as calponin or FXR1 can reveal gain-of-function effects on actomyosin organization and cell behavior. Overexpression models are useful for testing sufficiency in driving actomyosin remodeling.
How EDITGENE Supports actomyosin structure organization Research
Researchers studying actomyosin structure organization-related genes often need to determine whether a candidate gene is causally involved in the assembly, arrangement, or disassembly of actin-myosin structures. EDITGENE provides CRISPR-based cell models and screening services to accelerate this causal dissection.
Contact EDITGENE today to design your custom CRISPR model for actomyosin structure organization research.
Frequently Asked Questions About actomyosin structure organization
What is actomyosin structure organization?
It is the biological process that assembles, arranges, and disassembles cytoskeletal structures containing actin and myosin, defined as GO:0031032.
What genes are involved in actomyosin structure organization?
Key genes include ACTB, MYH9, MYH10, CNN1, MYO18A, FXR1, RAC1, and ITGB1, among others.
What is the role of myosin chaperones in actomyosin organization?
Myosin chaperones ensure proper folding and assembly of myosin motors, which are essential for actomyosin function.
How does calponin regulate actomyosin?
Calponin binds actin and modulates actin-myosin interactions, influencing contractility and filament stability.
What diseases are linked to actomyosin structure organization?
Cancer metastasis, kidney repair defects, immune cell migration disorders, and developmental malformations.
How can I study actomyosin structure organization in the lab?
Use live-cell imaging, proteomics, CRISPR perturbation, and mechanical measurements.
What is the role of Rac1 in actomyosin organization?
Rac1 promotes kidney collecting duct repair by mechanically coupling cell morphology to mitotic entry via actomyosin.
How does FXR1 regulate actomyosin remodeling?
The FXR1 network acts as a signaling scaffold that coordinates actomyosin remodeling.
What are actin stress fibers?
Actin stress fibers are contractile bundles of actin and myosin that transmit forces and are central to actomyosin organization.
Can CRISPR be used to study actomyosin genes?
Yes, CRISPR knockout, point mutation, knock-in, and overexpression models enable causal dissection of actomyosin gene function.
Conclusion
Actomyosin structure organization (GO:0031032) is a fundamental biological process that builds, arranges, and disassembles actin-myosin structures to drive cell shape change, migration, and tissue morphogenesis. Its dysregulation is implicated in cancer, kidney injury, immune disorders, and developmental defects. By combining CRISPR-based cell models with advanced imaging and proteomics, researchers can dissect the causal roles of individual genes and identify new therapeutic targets.
References
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- 3. Hellerschmied D et al.. 2014. Myosin chaperones.. Curr Opin Struct Biol 25(100):9-15 PMID: 24440450
- 4. Lu Q et al.. 2019. Ascidian notochord elongation.. Dev Biol 448(2):147-153 PMID: 30458170
- 5. Chen X et al.. 2024. The FXR1 network acts as a signaling scaffold for actomyosin remodeling.. Cell 187(18):5048-5063.e25 PMID: 39106863
- 6. Kaltenbach L et al.. 2023. Slow integrin-dependent migration organizes networks of tissue-resident mast cells.. Nat Immunol 24(6):915-924 PMID: 37081147
- 7. Bock F et al.. 2024. Rac1 promotes kidney collecting duct repair by mechanically coupling cell morphology to mitotic entry.. Sci Adv 10(6):eadi7840 PMID: 38324689
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