GO:0090543 Flemming body: Components, Assembly and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0090543 Flemming body is the central region of the midbody, defined by a gap in alpha-tubulin staining and a dense bundle of antiparallel microtubules.
• It is also called the midbody ring and serves as a signaling and structural hub during the final steps of cytokinesis.
• Class I Arfs (Arf1 and Arf3) and Arf6 localize to the Flemming body and are required for abscission.
• The Arf6-MKLP1 complex forms on the Flemming body and is structurally required for cytokinesis.
• EFA6 activates Arf6 and targets it to the Flemming body, linking membrane trafficking to midbody function.
• Flemming body research uses live-cell imaging, proteomics, and CRISPR models to dissect abscission and disease links.
Description
The Flemming body (GO:0090543) is a cellular component defined as the central region of the midbody, characterized by a gap in alpha-tubulin staining and a dense structure of antiparallel microtubules from the central spindle in the middle of the intercellular bridge. It is also known as the midbody ring and was first described in the context of animal cell division. Understanding this structure is essential because it coordinates the final separation of daughter cells, a process called abscission, and serves as a platform for recruiting proteins that regulate membrane remodeling and cytoskeletal dynamics. Researchers study the Flemming body to uncover mechanisms of cytokinesis, to identify targets for cancer therapy, and to understand how defects in cell division contribute to disease.
Flemming body At A Glance
| GO ID | GO:0090543 |
|---|---|
| GO term | Flemming body |
| Ontology | cellular_component |
| Synonym | Midbody ring |
| Major function | Central region of the midbody; dense antiparallel microtubule bundle; site for abscission machinery assembly |
| Definition | A cell part that is the central region of the midbody characterized by a gap in alpha-tubulin staining; a dense structure of antiparallel microtubules from the central spindle in the middle of the intercellular bridge |
| Related process | Cytokinesis, abscission |
| Key proteins | Arf1, Arf3, Arf6, MKLP1, EFA6 |
What Is GO:0090543?
The Flemming body is the central, dense region of the midbody, marked by a gap in alpha-tubulin staining. It consists of antiparallel microtubules from the central spindle and is located in the middle of the intercellular bridge that connects dividing cells. This structure is also called the midbody ring and acts as a hub for protein recruitment during cytokinesis.
Why Is Flemming body Important in Cell Biology?
The Flemming body is critical for cytokinesis because it recruits and organizes the molecular machinery that drives abscission, the final step of cell division. Disruption of Flemming body components leads to failed cytokinesis, which can result in binucleation, genomic instability, and tumorigenesis. Moreover, the Flemming body is a signaling platform for small GTPases such as Arf6, which regulates membrane trafficking and actin dynamics during abscission. Studying this structure provides insights into fundamental cell biology and potential therapeutic targets for cancer and developmental disorders.
• Essential for abscission, the final step of cytokinesis.
• Recruits Arf6 and MKLP1 to coordinate microtubule and membrane remodeling.
• Defects lead to binucleation and genomic instability, hallmarks of cancer.
• Serves as a platform for EFA6-mediated Arf6 activation.
• Involved in cell cycle regulation and checkpoint control.
• Potential target for anti-cancer therapies that block cytokinesis.
• Key to understanding developmental disorders linked to cytokinesis failure.
• Model system for studying membrane trafficking at the midbody.
• Provides insights into asymmetric cell division and stem cell biology.
• Links cytoskeletal dynamics to vesicle transport during cell division.
What Happens During Flemming body?
Formation of the Flemming body
In simple terms: The Flemming body forms in the middle of the bridge connecting two dividing cells.
During late cytokinesis, antiparallel microtubules from the central spindle bundle tightly at the midbody, creating a dense structure with a gap in alpha-tubulin staining, known as the Flemming body. This structure is first visible in anaphase and persists until abscission.
Recruitment of Arf6 and MKLP1
In simple terms: Specific proteins are recruited to the Flemming body to help cut the cell in two.
The Flemming body recruits class I Arfs (Arf1 and Arf3) and Arf6, which localize to this structure and play important roles in cytokinesis. The Arf6-MKLP1 complex forms on the Flemming body, and its crystal structure reveals a specific interaction essential for cytokinesis.
Activation of Arf6 by EFA6
In simple terms: EFA6 activates Arf6 at the Flemming body to promote membrane changes needed for abscission.
EFA6, a guanine nucleotide exchange factor, activates Arf6 and participates in its targeting to the Flemming body during cytokinesis. This activation is required for the membrane remodeling that leads to abscission.
Abscission and completion of cytokinesis
In simple terms: The Flemming body helps pinch off the bridge so the two cells separate.
The Flemming body serves as a platform for the abscission machinery, including ESCRT proteins, which finalize the separation of daughter cells. Disruption of Flemming body components blocks abscission, leading to binucleation.
Key Genes Involved in GO:0090543 Flemming body
The following genes and proteins are key players in Flemming body function and cytokinesis.
| Gene | Major Role | Research Relevance |
|---|---|---|
| ARF6 | Localizes to Flemming body; regulates membrane trafficking during abscission | Knockout causes cytokinesis failure; target for cancer studies |
| ARF1 | Class I Arf; localizes to Flemming body; involved in cytokinesis | Potential redundant role with ARF3; knockout models |
| ARF3 | Class I Arf; localizes to Flemming body; involved in cytokinesis | Potential redundant role with ARF1; knockout models |
| MKLP1 | Kinesin-like motor; binds Arf6 on Flemming body; essential for central spindle | Point mutations disrupt Arf6 binding; cytokinesis defects |
| EFA6 | GEF that activates Arf6 and targets it to Flemming body | Knockdown impairs abscission; live-cell imaging |
| ESCRT-III | Mediates membrane scission at midbody | Knockout blocks abscission; imaging studies |
| CEP55 | Centrosomal protein; recruits ESCRT to midbody | Knockout causes abscission failure |
| CHMP4B | ESCRT-III subunit; polymerizes at midbody | Mutations linked to cataracts; cytokinesis defects |
| VPS4 | AAA-ATPase; recycles ESCRT components | Knockout leads to abscission arrest |
| RAB11 | Vesicle trafficking; delivers membranes to midbody | Knockdown impairs abscission |
| ANCHR | Negative regulator of abscission; binds VPS4 | Overexpression delays abscission |
| SPASTIN | Microtubule severing at midbody | Mutations cause hereditary spastic paraplegia |
| KIF14 | Kinesin motor; localizes to midbody | Knockout causes cytokinesis failure |
| PRC1 | Microtubule bundling; central spindle formation | Knockout disrupts Flemming body formation |
| AURKB | Kinase; regulates abscission checkpoint | Inhibitors block cytokinesis |
| PLK1 | Kinase; regulates midbody assembly | Inhibitors cause cytokinesis defects |
| CYK4 | RhoA GAP; localizes to midbody | Knockdown impairs abscission |
| ECT2 | RhoA GEF; central spindle formation | Knockout disrupts cytokinesis |
How Is Flemming body Regulated?
The Flemming body is regulated by small GTPases, kinases, and the abscission checkpoint. Arf6 activation by EFA6 is a key regulatory step for targeting to the Flemming body. The Arf6-MKLP1 complex formation is structurally regulated and essential for cytokinesis. Aurora B kinase and Plk1 regulate the abscission checkpoint, delaying abscission in response to chromatin bridges. Additionally, ESCRT-III polymerization and VPS4-mediated recycling are tightly controlled to ensure proper membrane scission.
Flemming body and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| ARF6 | Cancer, cytokinesis failure | Knockout in HeLa cells; xenograft models |
| MKLP1 | Cancer, developmental defects | Point mutation knock-in in zebrafish |
| SPASTIN | Hereditary spastic paraplegia | Knockout in neurons; patient iPSCs |
| CHMP4B | Cataracts, cytokinesis defects | Knock-in in mouse models |
| EFA6 | Cancer, abscission defects | Overexpression in cancer cell lines |
Cancer and genomic instability
Defects in Flemming body components, such as Arf6 or MKLP1, lead to failed abscission and binucleation, which can cause genomic instability and promote tumorigenesis. Overexpression of EFA6 or Arf6 has been observed in some cancers, making them potential therapeutic targets.
Developmental disorders
Mutations in genes encoding Flemming body proteins, such as SPASTIN, are linked to hereditary spastic paraplegia, a neurodegenerative disorder. Other cytokinesis genes are associated with developmental syndromes characterized by microcephaly and growth retardation.
Cytokinesis and infertility
Disruption of Flemming body function can impair germ cell division, potentially leading to infertility. Studies in model organisms show that mutations in midbody components cause defective spermatogenesis.
From Flemming body-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does ARF6 knockout block abscission? | ARF6 knockout cell line (e.g., HeLa) |
| How does MKLP1 point mutation affect Arf6 binding? | MKLP1 point-mutation knock-in |
| Can tagged Arf6 track Flemming body dynamics? | Knock-in of fluorescently tagged Arf6 |
| Does EFA6 overexpression accelerate abscission? | EFA6 overexpression cell line |
| What is the role of ESCRT-III in abscission? | CHMP4B knockout |
| Can CRISPR screen identify novel Flemming body genes? | Genome-wide CRISPR library screening |
How to Study the Flemming body Process
| Method | What It Measures | Typical Application |
|---|---|---|
| Live-cell imaging | Dynamics of Flemming body and abscission | Tracking GFP-tagged proteins |
| Proteomics | Protein composition of midbody | Identifying novel components |
| CRISPR knockout screening | Genes required for cytokinesis | Genome-wide screens |
| Crystallography | 3D structure of protein complexes | Arf6-MKLP1 interface |
| RNA-seq | Transcriptional changes upon knockout | Pathway analysis |
| Immunofluorescence | Localization of proteins at midbody | Alpha-tubulin gap staining |
| FRET | Protein-protein interactions in live cells | Arf6-MKLP1 binding |
Live-cell imaging
Live-cell imaging with fluorescently tagged proteins (e.g., GFP-Arf6) allows real-time visualization of Flemming body dynamics and abscission.
Proteomics
Mass spectrometry-based proteomics of isolated midbodies can identify novel Flemming body components and their interactions.
CRISPR screening
Genome-wide CRISPR knockout screens can uncover genes required for Flemming body formation and abscission.
Structural biology
X-ray crystallography and cryo-EM reveal the structural basis of Arf6-MKLP1 complex formation on the Flemming body.
How CRISPR Can Be Used to Study GO:0090543 Flemming body
Knockout
CRISPR knockout of ARF6 or MKLP1 in cell lines results in failed abscission and binucleation, providing causal evidence for their role in Flemming body function.
Point Mutation
Point mutations in MKLP1 that disrupt Arf6 binding can be introduced via CRISPR to study the structural requirements for Flemming body assembly.
Knock-in
Knock-in of fluorescent tags (e.g., GFP) into endogenous ARF6 or MKLP1 loci allows real-time tracking of Flemming body dynamics.
Overexpression
Overexpression of EFA6 or Arf6 using CRISPR activation or cDNA constructs can test their sufficiency to drive abscission.
How EDITGENE Supports Flemming body Research
Researchers studying Flemming body-related genes often need to determine whether a candidate gene is causally involved in cytokinesis or abscission. EDITGENE provides a comprehensive suite of CRISPR services to accelerate this research.
Contact EDITGENE today to design your custom CRISPR model for Flemming body research.
Frequently Asked Questions About Flemming body
What is the Flemming body?
The Flemming body (GO:0090543) is the central region of the midbody, characterized by a gap in alpha-tubulin staining and a dense bundle of antiparallel microtubules.
What genes are involved in the Flemming body?
Key genes include ARF6, ARF1, ARF3, MKLP1, and EFA6, which localize to the Flemming body and regulate cytokinesis.
What is the function of the Flemming body?
It serves as a platform for recruiting abscission machinery, including ESCRT proteins, to complete cell division.
Where is the Flemming body located?
It is located in the middle of the intercellular bridge connecting two dividing cells, at the center of the midbody.
What is another name for the Flemming body?
It is also known as the midbody ring.
How is the Flemming body studied?
Common methods include live-cell imaging, proteomics, CRISPR screening, and structural biology.
What happens if the Flemming body is disrupted?
Disruption leads to failed abscission, binucleation, and genomic instability, which can contribute to cancer.
Is the Flemming body involved in disease?
Yes, defects in Flemming body components are linked to cancer, developmental disorders, and hereditary spastic paraplegia.
What is the Arf6-MKLP1 complex?
It is a protein complex that forms on the Flemming body and is essential for cytokinesis, with a defined crystal structure.
How does EFA6 regulate the Flemming body?
EFA6 activates Arf6 and targets it to the Flemming body, promoting membrane remodeling during abscission.
Conclusion
The Flemming body (GO:0090543) is a central structure in cytokinesis, essential for abscission and genomic stability. Its components, including Arf6, MKLP1, and EFA6, are critical for recruiting machinery that separates daughter cells. Dysregulation of Flemming body function is linked to cancer and developmental disorders, making it a compelling target for further research. Advances in CRISPR-based models and imaging techniques continue to unravel its molecular mechanisms, offering potential therapeutic avenues.
References
- 2. Hanai A et al.. 2016. Class I Arfs (Arf1 and Arf3) and Arf6 are localized to the Flemming body and play important roles in cytokinesis.. J Biochem 159(2):201-8 PMID: 26330566
- 3. Makyio H et al.. 2012. Structural basis for Arf6-MKLP1 complex formation on the Flemming body responsible for cytokinesis.. EMBO J 31(11):2590-603 PMID: 22522702
- 4. Paweletz N. 1967. [On the function of the "Flemming body" during division of animal cells].. Naturwissenschaften 54(20):533-5 PMID: 5596294
- 5. Ueda T et al.. 2013. EFA6 activates Arf6 and participates in its targeting to the Flemming body during cytokinesis.. FEBS Lett 587(11):1617-23 PMID: 23603394
