GO:0007084 mitotic nuclear membrane reassembly: Mechanism, Genes, Functions and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0007084 describes the ESCRTIII-dependent process that reforms the nuclear envelope after mitosis, including resealing of the nuclear envelope in closed mitosis.
• LEM2 phase separation and CHMP7 recruitment are critical for ESCRT-III polymerization at the reforming nuclear envelope.
• Dephosphorylation of mitotic phosphosites by phosphatases such as PP1 and PP2A is required for nuclear reassembly.
• Defects in nuclear envelope reassembly are linked to cancer, laminopathies, and genome instability.
• Key proteins include LEM2, CHMP7, VPS4, UFD1, NPL4, and nuclear pore complex components such as NUP153 and NUP50.
• CRISPR knockout, knock-in, and overexpression models are essential to dissect the molecular players in this pathway.
Description
Mitotic nuclear membrane reassembly (GO:0007084) is the biological process that rebuilds the nuclear envelope after chromosome segregation, ensuring that the newly formed daughter nuclei are enclosed by a functional membrane barrier. This process is essential for maintaining genome integrity and for proper cell cycle progression, as failure to reassemble the nuclear envelope leads to persistent nuclear envelope ruptures, DNA damage, and cell death. In organisms undergoing closed mitosis, such as many fungi and some protists, the nuclear envelope does not completely disassemble; instead, it must be resealed or repaired at the nuclear bridge. The process is highly conserved and involves the endosomal sorting complex required for transport (ESCRT-III) machinery, which mediates membrane scission and sealing. Research into GO:0007084 has gained momentum because defects in nuclear envelope reassembly are increasingly implicated in cancer, premature aging, and neurodegenerative disorders. Understanding the molecular players and regulatory mechanisms of this process is therefore critical for developing therapeutic strategies that target nuclear envelope integrity.
mitotic nuclear membrane reassembly At A Glance
| GO ID | GO:0007084 |
|---|---|
| GO term | mitotic nuclear membrane reassembly |
| Ontology | biological_process |
| Synonym | mitotic nuclear envelope reassembly; nuclear envelope repair; nuclear envelope resealing |
| Major function | Reformation and sealing of the nuclear envelope after mitosis, mediated by ESCRT-III |
| Cellular location | Nuclear envelope, nuclear bridge (in closed mitosis) |
| Key machinery | ESCRT-III complex, LEM2, CHMP7, VPS4, nuclear pore complex proteins |
| Related processes | Mitotic nuclear division, nuclear pore complex assembly, membrane scission |
What Is GO:0007084?
According to the Gene Ontology, GO:0007084 (mitotic nuclear membrane reassembly) is defined as the mitotic cell cycle process involving ESCRTIII that results in reformation of the nuclear envelope after mitotic nuclear division. In organisms undergoing closed mitosis, this involves resealing or repair of the nuclear envelope in the nuclear bridge. Synonyms include mitotic nuclear envelope reassembly, nuclear envelope repair, and nuclear envelope resealing.
Why Is mitotic nuclear membrane reassembly Important in Cell Biology?
Mitotic nuclear membrane reassembly is fundamental for cell survival because it restores the physical barrier between the nucleus and cytoplasm, which is essential for nuclear compartmentalization, chromatin organization, and genome stability. Defects in this process cause nuclear envelope ruptures, DNA damage, and aneuploidy, all of which are hallmarks of cancer and aging-related diseases. Moreover, the machinery involved, such as ESCRT-III and LEM2, is conserved across eukaryotes, making it a valuable target for understanding basic cell biology and for developing therapeutic interventions.
• Maintains genome integrity by preventing nuclear envelope ruptures that lead to DNA damage.
• Ensures proper nuclear compartmentalization after each cell division.
• Dysregulation is linked to cancer progression and metastasis.
• Mutations in nuclear envelope proteins cause laminopathies and premature aging syndromes.
• Required for the inheritance of shattered micronuclear chromosomes.
• ESCRT-III components are potential targets for antiviral and anticancer therapies.
• Defects in reassembly trigger innate immune responses via cGAS-STING.
• Essential for closed mitosis in fungi and protists, affecting pathogenicity.
• Provides a model for studying membrane remodeling and phase separation.
• Involved in the repair of nuclear envelope ruptures during cell migration.
What Happens During mitotic nuclear membrane reassembly?
Initiation at the chromatin surface
In simple terms: The process starts when the new nuclear envelope begins to form around the separated chromosomes.
After anaphase, the nuclear envelope starts to reassemble on the surface of decondensing chromatin. This initiation step involves the recruitment of LEM2 (LEM domain-containing protein 2) to the chromatin, where it undergoes phase separation to form a concentrated platform for downstream factors. LEM2 directly binds to CHMP7, a subunit of the ESCRT-III machinery, and this interaction is essential for the subsequent polymerization of ESCRT-III filaments. The dephosphorylation of mitotic phosphosites on LEM2 and other nuclear envelope proteins by phosphatases such as PP1 and PP2A is a prerequisite for their function in reassembly. In closed mitosis, the initiation occurs at the nuclear bridge, where the inner and outer nuclear membranes must be resealed.
ESCRT-III polymerization and membrane scission
In simple terms: A protein complex forms a spiral that pinches the membrane to close the nuclear envelope.
Following recruitment, CHMP7 nucleates the assembly of ESCRT-III filaments composed of CHMP4B, CHMP2A, and CHMP3. These filaments constrict the membrane and, with the help of the AAA-ATPase VPS4, catalyze membrane scission to seal the nuclear envelope. This step is highly regulated by phosphorylation and dephosphorylation events; for example, CHMP7 is phosphorylated during mitosis and must be dephosphorylated to interact with LEM2. The ESCRT-III machinery also plays a role in repairing nuclear envelope ruptures that occur during interphase, highlighting its versatility.
Nuclear pore complex reformation
In simple terms: The pores that control traffic in and out of the nucleus are rebuilt.
Simultaneously with membrane sealing, nuclear pore complexes (NPCs) are reassembled from disassembled components. The process involves the recruitment of nucleoporins such as NUP153, NUP50, and NUP98 to the reforming nuclear envelope. This step is critical for restoring nucleocytoplasmic transport and is coordinated with membrane reassembly through shared regulatory factors. In plants, the nucleoporin PNET1 coordinates mitotic NPC dynamics to ensure rapid cell division. Defects in NPC reformation can lead to nuclear envelope reassembly defects and cell cycle arrest.
Resolution and quality control
In simple terms: The cell checks that the nuclear envelope is fully sealed and fixes any holes.
After the initial sealing, quality control mechanisms ensure that the nuclear envelope is continuous and functional. This involves the removal of excess ESCRT-III components by VPS4 and the action of the ubiquitin-proteasome system. The LEM2-CHMP7 interaction is also regulated by the ubiquitin ligase UFD1-NPL4, which extracts CHMP7 from the membrane after scission. In cells with persistent DNA damage, such as those with micronuclei, reassembly defects can trigger further repair pathways, including TMEJ (theta-mediated end joining), which suppresses replication stress-induced nuclear envelope reassembly defects. The clustering of pulverized chromosomes from micronuclei also depends on proper reassembly to prevent genome chaos.
Key Genes Involved in GO:0007084 mitotic nuclear membrane reassembly
The following genes and proteins are central to mitotic nuclear membrane reassembly, as supported by the cited literature.
| Gene | Major Role | Research Relevance |
|---|---|---|
| LEM2 | Chromatin-binding protein that phase separates to recruit ESCRT-III | Key initiator; mutations linked to nuclear envelope defects |
| CHMP7 | ESCRT-III subunit that nucleates filament assembly | Essential for membrane scission; regulated by phosphorylation |
| CHMP4B | Core ESCRT-III component | Polymerizes to constrict membrane |
| CHMP2A | ESCRT-III component | Required for membrane scission |
| VPS4 | AAA-ATPase that disassembles ESCRT-III | Energy-dependent resolution of filaments |
| UFD1 | Ubiquitin ligase adaptor | Extracts CHMP7 from membrane |
| NPL4 | Ubiquitin ligase adaptor | Works with UFD1 in CHMP7 removal |
| NUP153 | Nuclear pore complex protein | NPC reformation |
| NUP50 | Nuclear pore complex protein | NPC reformation |
| NUP98 | Nuclear pore complex protein | NPC reformation |
| PNET1 | Plant nucleoporin | Coordinates mitotic NPC dynamics |
| PP1 | Protein phosphatase 1 | Dephosphorylates nuclear envelope proteins |
| PP2A | Protein phosphatase 2A | Dephosphorylates nuclear envelope proteins |
| TMEJ | Theta-mediated end joining | Suppresses replication stress-induced reassembly defects |
| cGAS | DNA sensor | Innate immune response to reassembly defects |
| STING | Immune adaptor | Innate immune response to reassembly defects |
| Lamin A/C | Nuclear lamina protein | Provides structural support; mutations cause laminopathies |
How Is mitotic nuclear membrane reassembly Regulated?
Mitotic nuclear membrane reassembly is regulated by reversible protein phosphorylation. Cyclin-dependent kinase 1 (CDK1) phosphorylates multiple nuclear envelope and ESCRT-III components during mitosis, and their dephosphorylation by PP1 and PP2A is required for reassembly. The LEM2-CHMP7 interaction is also controlled by the ubiquitin-proteasome system, with UFD1-NPL4 mediating the extraction of CHMP7 after membrane scission. In addition, the DNA damage response and replication stress can influence reassembly efficiency through pathways such as TMEJ. In plants, the nucleoporin PNET1 is regulated to coordinate NPC dynamics with cell cycle progression.
mitotic nuclear membrane reassembly and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| LMNA | Hutchinson-Gilford progeria syndrome, muscular dystrophy | Patient-derived iPSCs with LMNA mutation; KO in HeLa |
| CHMP7 | Cancer, genome instability | CHMP7 knockout in cancer cell lines; overexpression |
| LEM2 | Nuclear envelope defects, cancer | LEM2 knockout in U2OS; knock-in of phase separation mutants |
| VPS4 | Neurodegeneration, cancer | VPS4 dominant-negative overexpression; KO |
| NUP153 | Cancer, nuclear pore disease | NUP153 knockout in HEK293T; tagged knock-in |
Cancer and genome instability
Defects in mitotic nuclear membrane reassembly lead to persistent nuclear envelope ruptures, which expose DNA to the cytoplasm and trigger DNA damage and inflammation. This genomic instability is a hallmark of cancer, and overexpression of ESCRT-III components such as CHMP7 has been observed in various tumors. Furthermore, the clustering of pulverized chromosomes from micronuclei, which depends on reassembly, can promote chromothripsis, a phenomenon frequently seen in cancer genomes.
Laminopathies and premature aging
Mutations in LMNA, which encodes Lamin A/C, cause a spectrum of diseases including Hutchinson-Gilford progeria syndrome and muscular dystrophies. These mutations impair nuclear envelope integrity and reassembly, leading to nuclear blebbing and increased DNA damage. Studies have shown that cells from progeria patients exhibit delayed nuclear envelope reassembly after mitosis, contributing to cellular senescence.
Neurodegeneration
Nuclear envelope defects are increasingly linked to neurodegenerative diseases such as amyotrophic lateral sclerosis (ALS) and frontotemporal dementia. Disruption of nuclear pore complexes and ESCRT-III function has been observed in ALS models, suggesting that impaired nuclear membrane reassembly may contribute to neuronal death.
From mitotic nuclear membrane reassembly-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does gene X regulate nuclear envelope reassembly? | CRISPR knockout in HeLa or U2OS cells followed by live-cell imaging |
| What is the role of a specific phosphorylation site? | Point mutation (phospho-deficient or phospho-mimetic) knock-in |
| How does a disease mutation affect reassembly? | Patient-derived iPSCs with knock-in of the mutation |
| Where does protein X localize during reassembly? | Endogenous tagged knock-in (e.g., GFP or HaloTag) |
| Does overexpression of gene Y cause reassembly defects? | Doxycycline-inducible overexpression in stable cell lines |
| Which genes are essential for reassembly? | Genome-wide CRISPR library screening with a reassembly reporter |
How to Study the mitotic nuclear membrane reassembly Process
| Method | What It Measures | Typical Application |
|---|---|---|
| Live-cell imaging | Dynamics of nuclear envelope sealing | Time-lapse of Lamin B1-GFP during mitosis |
| AP-MS | Protein-protein interactions | Identifying LEM2/CHMP7 interactors |
| BioID | Proximity-dependent biotinylation | Mapping the reassembly interactome |
| CRISPR knockout screen | Gene essentiality for reassembly | Genome-wide screen with a nuclear envelope reporter |
| CLEM | Ultrastructure of membrane sealing | Visualizing ESCRT-III filaments at the nuclear envelope |
| Phosphoproteomics | Changes in phosphorylation during mitosis | Identifying dephosphorylation events required for reassembly |
| RNA-seq | Transcriptional changes | Comparing wild-type and reassembly-defective cells |
Live-cell imaging
Live-cell imaging using fluorescently tagged nuclear envelope proteins (e.g., Lamin B1-GFP) and ESCRT-III components allows real-time visualization of reassembly dynamics. This method can quantify the timing and efficiency of nuclear envelope sealing after mitosis.
Proteomics and interactomics
Affinity purification coupled with mass spectrometry (AP-MS) can identify novel interactors of LEM2, CHMP7, and other key proteins during reassembly. Proximity labeling (BioID) can capture transient interactions at the reforming nuclear envelope.
CRISPR screening
Genome-wide CRISPR knockout screens using a reporter of nuclear envelope integrity (e.g., mislocalization of a nuclear protein) can identify genes required for reassembly. This approach has the power to uncover previously unknown regulators.
Electron microscopy
Correlative light and electron microscopy (CLEM) provides ultrastructural details of membrane sealing and ESCRT-III filament organization at the nuclear envelope. This method is essential for understanding the membrane remodeling steps.
How CRISPR Can Be Used to Study GO:0007084 mitotic nuclear membrane reassembly
Knockout
CRISPR knockout of genes such as LEM2, CHMP7, or VPS4 in cell lines like HeLa or U2OS can reveal their essential roles in nuclear envelope reassembly. Knockout cells often exhibit nuclear envelope ruptures, delayed reassembly, and increased DNA damage, which can be quantified by immunofluorescence and live-cell imaging.
Point Mutation
Introducing point mutations that mimic or prevent phosphorylation (e.g., in CHMP7 or LEM2) can dissect the regulatory role of specific residues. For example, phospho-deficient mutants may fail to interact with partners, leading to reassembly defects.
Knock-in
Knock-in of fluorescent tags (e.g., GFP, HaloTag) at endogenous loci allows visualization of protein dynamics during reassembly without overexpression artifacts. Disease-associated mutations can also be knocked in to model their impact on reassembly.
Overexpression
Overexpression of wild-type or mutant forms of ESCRT-III components can cause dominant-negative effects or enhance reassembly. Inducible systems are preferred to avoid toxicity. Overexpression of CHMP7, for instance, can lead to excessive membrane scission and nuclear envelope defects.
How EDITGENE Supports mitotic nuclear membrane reassembly Research
Researchers studying mitotic nuclear membrane reassembly-related genes often need to determine whether a candidate gene is causally involved in the process or merely correlated. EDITGENE provides a comprehensive suite of CRISPR services to enable precise genetic perturbations and functional studies.
Contact EDITGENE today to design your custom CRISPR model for mitotic nuclear membrane reassembly research.
Frequently Asked Questions About mitotic nuclear membrane reassembly
What is GO:0007084?
GO:0007084 is the Gene Ontology term for mitotic nuclear membrane reassembly, the process that reforms the nuclear envelope after mitosis, involving ESCRT-III.
What genes are involved in mitotic nuclear membrane reassembly?
Key genes include LEM2, CHMP7, CHMP4B, VPS4, UFD1, NPL4, and nuclear pore complex components such as NUP153 and NUP50.
What is the role of ESCRT-III in nuclear envelope reassembly?
ESCRT-III polymerizes into filaments that constrict and seal the nuclear envelope, a process mediated by CHMP7 and other subunits.
How is nuclear envelope reassembly regulated?
It is regulated by phosphorylation and dephosphorylation events, with PP1 and PP2A phosphatases playing key roles.
What diseases are associated with defective nuclear envelope reassembly?
Defects are linked to cancer, laminopathies such as progeria, and neurodegenerative diseases.
What methods are used to study mitotic nuclear membrane reassembly?
Common methods include live-cell imaging, proteomics, CRISPR screens, and electron microscopy.
What is the difference between open and closed mitosis in nuclear envelope reassembly?
In open mitosis, the nuclear envelope completely disassembles and reassembles; in closed mitosis, it remains intact but must be resealed at the nuclear bridge.
Which proteins are involved in nuclear pore complex reformation during reassembly?
Nucleoporins such as NUP153, NUP50, and NUP98 are recruited to the reforming nuclear envelope.
How does LEM2 contribute to nuclear envelope reassembly?
LEM2 phase separates at the chromatin surface to recruit CHMP7 and initiate ESCRT-III polymerization.
Can CRISPR be used to study mitotic nuclear membrane reassembly?
Yes, CRISPR knockout, knock-in, and point mutation models are powerful tools to dissect gene function in this process.
Conclusion
Mitotic nuclear membrane reassembly (GO:0007084) is a tightly regulated process essential for genome stability and cell survival. The ESCRT-III machinery, LEM2, and nuclear pore components coordinate to seal the nuclear envelope after mitosis, and defects in this process contribute to cancer, aging, and neurodegeneration. Continued research using advanced CRISPR models and imaging techniques will further illuminate the molecular mechanisms and therapeutic potential of targeting this pathway.
References
- 1. Kutay U et al.. 2021. Mitotic disassembly and reassembly of nuclear pore complexes.. Trends Cell Biol 31(12):1019-1033 PMID: 34294532
- 2. Kono Y et al.. 2024. Crosstalk between mitotic reassembly and repair of the nuclear envelope.. Nucleus 15(1):2352203 PMID: 38780365
- 3. Ye G et al.. 2025. Mitotic DNA repair by TMEJ suppresses replication stress-induced nuclear envelope reassembly defect.. Nat Commun 16(1):8836 PMID: 41044090
- 4. Archambault V et al.. 2022. Dephosphorylation in nuclear reassembly after mitosis.. Front Cell Dev Biol 10:1012768 PMID: 36268509
- 5. Lin YF et al.. 2023. Mitotic clustering of pulverized chromosomes from micronuclei.. Nature 618(7967):1041-1048 PMID: 37165191
- 6. von Appen A et al.. 2020. LEM2 phase separation promotes ESCRT-mediated nuclear envelope reformation.. Nature 582(7810):115-118 PMID: 32494070
- 7. Fang Y et al.. 2025. Nucleoporin PNET1 coordinates mitotic nuclear pore complex dynamics for rapid cell division.. Nat Plants 11(2):295-308 PMID: 39890949
- 8. Trivedi P et al.. 2023. Mitotic tethering enables inheritance of shattered micronuclear chromosomes.. Nature 618(7967):1049-1056 PMID: 37316668
