GO:0005638 lamin filament: Components, Assembly and Research Methods, Genes, Functions and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0005638 (lamin filament) describes the intermediate-filament proteins (lamins A, B and C) that polymerize into the fibrous meshwork lining the inner surface of the nuclear envelope.
• Lamin filaments are type V intermediate filaments built from antiparallel coiled-coil dimers that assemble into higher-order filaments at the nuclear periphery.
• Lamins anchor chromatin and lamin-binding proteins at the nuclear envelope, influencing transcription, chromatin organization and genome stability.
• Mutations in lamin genes cause laminopathies, including muscular dystrophies, lipodystrophies and premature aging syndromes.
• Lamin filaments participate in DNA double-strand break repair by forming nuclear envelope tubules that capture damaged DNA.
• CRISPR knockout, point-mutation, knock-in and overexpression models are key tools for dissecting lamin filament function in health and disease.
Description
The lamin filament (GO:0005638) is a cellular component defined as any of a group of intermediate-filament proteins that form the fibrous matrix on the inner surface of the nuclear envelope, classified as lamins A, B and C. These filaments are not merely structural scaffolds; they provide mechanical support to the nucleus and organize the spatial arrangement of chromatin and nuclear pore complexes. Because lamins are type V intermediate filaments, their assembly principles differ from cytoplasmic intermediate filaments, and recent atomic structures have clarified how antiparallel four-helix bundles drive polymerization. Understanding lamin filament biology is therefore central to nuclear architecture, mechanotransduction and genome maintenance. Lamin filaments matter to researchers because they are directly implicated in human disease. Mutations in LMNA and related lamin genes cause laminopathies such as Emery-Dreifuss muscular dystrophy, familial partial lipodystrophy and Hutchinson-Gilford progeria syndrome. Beyond rare genetic disorders, lamin expression and post-translational processing influence immune cell function and cancer progression. Lamin filaments also contribute to DNA repair by forming nuclear envelope tubules that capture double-strand breaks, linking nuclear envelope biology to genome stability. This article synthesizes authoritative QuickGO annotation for GO:0005638 with verified PubMed literature to describe the composition, assembly, regulation and disease relevance of lamin filaments. It also outlines how CRISPR-based models and modern methods can be used to interrogate lamin filament function, providing a practical resource for biomedical researchers.
lamin filament At A Glance
| GO ID | GO:0005638 |
|---|---|
| GO term | lamin filament |
| Ontology | cellular_component |
| Synonym | type V intermediate filament |
| Definition | Any of a group of intermediate-filament proteins that form the fibrous matrix on the inner surface of the nuclear envelope; classified as lamins A, B and C. |
| Major function | Provides structural support to the nuclear envelope and organizes chromatin and nuclear proteins. |
| Protein class | Type V intermediate filament proteins (lamins A, B and C). |
| Subcellular location | Inner surface of the nuclear envelope. |
| Related disease | Laminopathies including muscular dystrophy, lipodystrophy and progeria. |
What Is GO:0005638?
GO:0005638 (lamin filament) is a cellular component term describing the intermediate-filament proteins that assemble into a fibrous matrix on the inner surface of the nuclear envelope. These proteins are classified as lamins A, B and C, and the synonym type V intermediate filament reflects their classification within the intermediate filament superfamily. The term captures the polymerized filament state rather than soluble lamin monomers, emphasizing the structural meshwork that underpins nuclear envelope integrity and chromatin organization.
Why Is lamin filament Important in Cell Biology?
Lamin filaments are essential for nuclear mechanical stability, chromatin organization and genome maintenance, and their dysfunction causes a spectrum of human diseases known as laminopathies. Because lamins interact with numerous lamin-binding proteins and chromatin regions, they sit at the interface of nuclear architecture and gene regulation. Recent work showing that nuclear envelope tubules capture DNA double-strand breaks further highlights lamin filaments as active participants in DNA repair. Consequently, studying GO:0005638 is critical for understanding development, aging, immunity and cancer.
• Lamin filaments maintain nuclear envelope integrity and protect against mechanical stress.
• They anchor chromatin and lamin-binding proteins, influencing gene expression and chromatin topology.
• Mutations in lamin genes cause laminopathies such as Emery-Dreifuss muscular dystrophy and progeria.
• Lamin filaments participate in DNA double-strand break repair via nuclear envelope tubules.
• They modulate immune cell function and inflammatory signaling.
• Lamin expression changes are observed in cancers and affect cell migration and invasion.
• They provide a model for studying type V intermediate filament assembly.
• Lamin filaments are targets for chemical intervention, e.g., NAT10 inhibition corrects laminopathic defects.
• They link nuclear envelope biology to aging and senescence.
• CRISPR models of lamin genes enable causal testing of lamin filament functions.
Structure and Composition of lamin filament
Lamin protein family and classification
In simple terms: Lamins are proteins that build a mesh inside the nucleus, and they come in A, B and C types.
Lamin filaments are composed of lamins A, B and C, which are type V intermediate filament proteins. The QuickGO definition classifies them as a group of intermediate-filament proteins forming the fibrous matrix on the inner surface of the nuclear envelope. B-type lamins are generally expressed in most cell types, while A-type lamins (lamin A and C) are developmentally regulated and often associated with differentiated cells. This composition determines the mechanical and regulatory properties of the nuclear envelope.
Antiparallel four-helix bundle assembly
In simple terms: Lamin proteins pair up in an antiparallel way to form the building blocks of the filament.
The atomic structure of the antiparallel four-helix bundle has provided a molecular basis for lamin filament assembly. Lamin dimers assemble through coiled-coil interactions, and the antiparallel arrangement is a hallmark of intermediate filament architecture. Studies in C. elegans lamin show that filament assembly can occur even in the absence of helix 1A, indicating flexibility in the assembly pathway. These structural insights explain how lamin filaments form stable polymers at the nuclear periphery.
Higher-order filament network at the nuclear envelope
In simple terms: The paired lamin proteins link together into a large net that lines the inside of the nuclear envelope.
Lamin dimers polymerize into higher-order filaments that form a fibrous matrix on the inner surface of the nuclear envelope. This network interacts with lamin-binding proteins such as emerin and SUN-domain proteins to connect the nucleoskeleton to the cytoskeleton. The filament network provides mechanical support and serves as a platform for chromatin organization. Disruption of this network leads to nuclear envelope instability and disease.
Lamin-chromatin interactions
In simple terms: The lamin net touches DNA and helps organize which genes are active or silent.
Lamin filaments interact with specific chromatin regions, and the molecular basis of lamin-specific chromatin interactions has been characterized. These interactions contribute to the spatial organization of the genome and to gene regulation. Lamin-binding proteins further mediate connections between lamins and chromatin-modifying complexes. Thus, the lamin filament is not a passive scaffold but an active regulator of chromatin state.
Nuclear envelope tubules and DNA repair
In simple terms: The nuclear envelope can form tubes that capture broken DNA to help repair it.
DNA double-strand break-capturing nuclear envelope tubules have been shown to drive DNA repair, linking lamin filament-associated structures to genome maintenance. These tubules are dynamic extensions of the nuclear envelope that concentrate repair factors. This function highlights an active role for the nuclear envelope and its lamin-based architecture in preserving genome integrity. It also suggests that lamin filaments contribute to DNA repair beyond their structural role.
Key Genes Involved in GO:0005638 lamin filament
The following genes encode lamin proteins and key lamin-binding partners that define the composition and function of the lamin filament (GO:0005638).
| Gene | Major Role | Research Relevance |
|---|---|---|
| LMNA | Encodes lamin A and lamin C, major A-type lamin filaments | Mutations cause laminopathies including muscular dystrophy and progeria |
| LMNB1 | Encodes lamin B1, a B-type lamin filament component | Altered in aging and cancer; regulates chromatin organization |
| LMNB2 | Encodes lamin B2, a B-type lamin filament component | Involved in nuclear envelope stability and brain development |
| LMNB3 | Encodes lamin B3, a B-type lamin variant | Studied in nuclear envelope assembly and germ cell development |
| EMD | Encodes emerin, a lamin-binding inner nuclear membrane protein | Mutations cause Emery-Dreifuss muscular dystrophy |
| LEMD3 | Encodes MAN1, a lamin-binding protein | Regulates TGF-beta signaling and bone density |
| SUN1 | Encodes SUN domain protein 1, links nucleoskeleton to cytoskeleton | Involved in nuclear positioning and mechanotransduction |
| SUN2 | Encodes SUN domain protein 2, LINC complex component | Required for nuclear envelope integrity |
| SYNE1 | Encodes nesprin-1, connects nuclear envelope to actin | Mutations cause muscular dystrophy and cerebellar ataxia |
| SYNE2 | Encodes nesprin-2, LINC complex component | Involved in nuclear positioning and cell migration |
| BANF1 | Encodes BAF, a lamin-binding chromatin protein | Mutations cause progeroid syndromes |
| NAT10 | Acetyltransferase that modifies lamin-associated proteins | Chemical inhibition corrects laminopathic defects |
| ZMPSTE24 | Protease that processes prelamin A | Mutations cause restrictive dermopathy and progeria |
| TPR | Nuclear pore complex protein interacting with lamins | Studied in nuclear envelope organization |
| NUP153 | Nuclear pore protein that binds lamins | Links nuclear pore complexes to lamin filaments |
| CHMP7 | ESCRT-III component involved in nuclear envelope repair | Implicated in DNA repair and nuclear envelope remodeling |
| ATM | DNA damage kinase that signals at nuclear envelope tubules | Central to DNA double-strand break repair |
| LBR | Lamin B receptor, binds lamin B filaments | Mutations cause Pelger-Huet anomaly |
How Is lamin filament Regulated?
Lamin filament assembly and function are regulated at multiple levels. Prelamin A is post-translationally processed by ZMPSTE24, and defects in this processing lead to progeroid phenotypes. Phosphorylation of lamins during mitosis regulates filament disassembly and reassembly, a process critical for nuclear envelope dynamics. Lamin-binding proteins such as emerin and BAF modulate lamin filament interactions with chromatin and the cytoskeleton. Chemical inhibition of NAT10 has been shown to correct defects in laminopathic cells, indicating that acetylation pathways regulate lamin-associated functions. Additionally, DNA damage signaling through ATM influences nuclear envelope tubule formation for repair. Together, these mechanisms ensure proper lamin filament dynamics in response to cellular cues.
lamin filament and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| LMNA | Emery-Dreifuss muscular dystrophy, progeria, lipodystrophy | Knockout and point-mutation iPSC-derived myocytes |
| ZMPSTE24 | Restrictive dermopathy, progeroid syndromes | Knockout mouse models and patient fibroblasts |
| EMD | Emery-Dreifuss muscular dystrophy | Knockout cell lines and muscle differentiation models |
| LMNB1 | Aging, cancer, chromatin organization | Overexpression and knockout cancer cell lines |
| NAT10 | Laminopathic cell defects | Chemical inhibition and CRISPR knockout in patient cells |
Laminopathies: muscular dystrophy, lipodystrophy and progeria
Mutations in LMNA and other lamin genes cause a group of disorders collectively known as laminopathies, which include Emery-Dreifuss muscular dystrophy, familial partial lipodystrophy and Hutchinson-Gilford progeria syndrome. These diseases arise from disrupted lamin filament assembly, impaired nuclear mechanical stability and altered chromatin organization. ZMPSTE24 mutations that prevent prelamin A processing also cause progeroid syndromes. Chemical inhibition of NAT10 has been shown to correct defects in laminopathic cells, suggesting potential therapeutic avenues.
Lamin filaments in immunity and inflammation
Lamin A/C and the immune system are interconnected, with lamin filaments influencing immune cell development, activation and inflammatory signaling. Alterations in lamin expression or processing can affect immune cell migration and function, contributing to autoinflammatory and autoimmune conditions. The mechanical properties of the nuclear envelope, governed by lamin filaments, are important for immune cell trafficking through tissues. Thus, lamin filament biology is relevant beyond rare genetic diseases to broader immune regulation.
Lamin filaments and genome stability in cancer and aging
Lamin filaments contribute to genome stability by participating in DNA double-strand break repair through nuclear envelope tubules. Defects in this process can lead to accumulation of DNA damage, a hallmark of cancer and aging. Lamin expression is frequently altered in cancers, affecting cell proliferation, migration and invasion. In aging, progerin accumulation disrupts nuclear architecture and accelerates senescence. These connections make lamin filaments attractive targets for understanding and potentially treating cancer and age-related diseases.
From lamin filament-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does loss of LMNA disrupt lamin filament assembly? | LMNA knockout cell lines and iPSC-derived cells |
| How do point mutations in LMNA cause progeria? | Point-mutation knock-in models expressing progerin |
| Can tagged lamins track filament dynamics? | Knock-in of fluorescent tags at endogenous LMNA locus |
| Does lamin overexpression alter chromatin organization? | Overexpression of LMNB1 or LMNA in cancer cell lines |
| What proteins interact with lamin filaments? | Knock-in of proximity-labeling tags (e.g., BioID) |
| How do lamin filaments participate in DNA repair? | Knockout of CHMP7 or ATM with DNA damage assays |
How to Study the lamin filament Process
| Method | What It Measures | Typical Application |
|---|---|---|
| Fluorescence microscopy | Lamin filament localization and dynamics | Assessing nuclear envelope integrity |
| Super-resolution microscopy | Nanoscale organization of lamin meshwork | Structural studies of lamin assembly |
| BioID proximity labeling | Lamin interactome in living cells | Identifying lamin-binding proteins |
| RNA-seq | Gene expression changes upon lamin perturbation | Linking lamin filaments to transcription |
| Hi-C / DamID | Chromatin organization and lamin-associated domains | Mapping genome-nuclear envelope interactions |
| Comet assay | DNA double-strand breaks | Testing lamin role in DNA repair |
| Western blot | Lamin protein levels and processing | Detecting progerin or prelamin A |
| CRISPR screening | Genes required for lamin filament function | Identifying modifiers of laminopathy phenotypes |
Imaging lamin filament structure
Fluorescence microscopy and live-cell imaging of tagged lamins allow visualization of lamin filament assembly and dynamics at the nuclear envelope. Super-resolution microscopy can resolve the meshwork structure, while electron microscopy provides ultrastructural details. These methods are essential for assessing how mutations alter filament organization.
Proteomics and interactomics
Affinity purification coupled with mass spectrometry identifies lamin-binding proteins and post-translational modifications. Proximity-labeling approaches such as BioID can map the lamin interactome in living cells. These techniques reveal how lamin filaments connect to chromatin and signaling pathways.
Genomic and transcriptomic profiling
RNA-seq and chromatin conformation capture (Hi-C) measure how lamin filaments influence gene expression and genome organization. Lamin-associated domains (LADs) can be mapped by DamID or ChIP-seq. These methods link lamin filament function to transcriptional regulation.
DNA repair assays
Comet assays, gamma-H2AX staining and reporter-based repair assays quantify DNA double-strand break repair in cells with altered lamin filament function. Live-cell imaging of nuclear envelope tubules can track their formation after damage. These approaches test the role of lamin filaments in genome stability.
How CRISPR Can Be Used to Study GO:0005638 lamin filament
Knockout
CRISPR knockout of LMNA, LMNB1 or LMNB2 enables researchers to study the consequences of losing specific lamin filaments on nuclear envelope structure, chromatin organization and cell viability. Knockout models have revealed essential roles for lamins in development and tissue homeostasis. These models are also used to test synthetic lethality with other nuclear envelope components.
Point Mutation
Introducing disease-associated point mutations into endogenous lamin genes via CRISPR allows precise modeling of laminopathies such as progeria and muscular dystrophy. Point-mutation models can reveal how single amino acid changes affect filament assembly and interactions. They are valuable for testing targeted therapies.
Knock-in
Knock-in of fluorescent or affinity tags at lamin loci permits real-time tracking of lamin filament dynamics and interactome mapping. Tagged knock-in models avoid overexpression artifacts and preserve endogenous regulation. They are particularly useful for studying lamin assembly and chromatin interactions.
Overexpression
Overexpression of wild-type or mutant lamins in cell lines can mimic pathological states such as lamin accumulation in cancer or progeria. Overexpression models help dissect dose-dependent effects on nuclear envelope function. They are also used to study lamin-chromatin interactions.
How EDITGENE Supports lamin filament Research
Researchers studying lamin filament-related genes often need to determine whether a candidate gene is causally involved in nuclear envelope function, chromatin organization or disease phenotypes. EDITGENE provides end-to-end CRISPR services to generate precisely engineered cell models that answer these questions.
Contact EDITGENE today to design your custom CRISPR model for lamin filament research.
Frequently Asked Questions About lamin filament
What is GO:0005638 lamin filament?
GO:0005638 is a cellular component term describing the intermediate-filament proteins (lamins A, B and C) that form the fibrous matrix on the inner surface of the nuclear envelope.
What genes are involved in lamin filament?
Key genes include LMNA, LMNB1, LMNB2, LMNB3, EMD, LEMD3, SUN1, SUN2, SYNE1, SYNE2, BANF1, ZMPSTE24 and NAT10.
What is the function of lamin filaments?
Lamin filaments provide mechanical support to the nuclear envelope, organize chromatin and participate in DNA repair.
How are lamin filaments assembled?
Lamin dimers form through antiparallel four-helix bundles and polymerize into higher-order filaments at the nuclear envelope.
What diseases are associated with lamin filaments?
Mutations in lamin genes cause laminopathies such as Emery-Dreifuss muscular dystrophy, familial partial lipodystrophy and Hutchinson-Gilford progeria syndrome.
How can CRISPR be used to study lamin filaments?
CRISPR knockout, point mutation, knock-in and overexpression models allow causal testing of lamin gene functions in cells and disease models.
What is the relationship between lamin filaments and DNA repair?
Nuclear envelope tubules capture DNA double-strand breaks and drive repair, linking lamin-associated structures to genome stability.
Which proteins bind to lamin filaments?
Lamin-binding proteins include emerin, MAN1, SUN1, SUN2, nesprin-1, nesprin-2, BAF and lamin B receptor.
How is lamin filament assembly regulated?
Regulation involves post-translational processing by ZMPSTE24, phosphorylation during mitosis and acetylation pathways such as NAT10.
What methods are used to study lamin filaments?
Common methods include fluorescence microscopy, super-resolution imaging, proteomics, RNA-seq, Hi-C, DamID and DNA repair assays.
Conclusion
GO:0005638 lamin filament represents a critical cellular component that underpins nuclear envelope integrity, chromatin organization and genome maintenance. Its dysfunction is linked to a broad spectrum of human diseases, from muscular dystrophies to progeria and cancer. Continued research using CRISPR models and advanced imaging will further elucidate how lamin filaments contribute to health and disease.
References
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- 3. Ahn J et al.. 2023. Lamin Filament Assembly Derived from the Atomic Structure of the Antiparallel Four-Helix Bundle.. Mol Cells 46(5):309-318 PMID: 37170772
- 4. Wilson KL et al.. 2010. Lamin-binding Proteins.. Cold Spring Harb Perspect Biol 2(4):a000554 PMID: 20452940
- 5. de Leeuw R et al.. 2022. Filament assembly of the C. elegans lamin in the absence of helix 1A.. Nucleus 13(1):49-57 PMID: 35130129
- 6. Wang B et al.. 2025. The molecular basis of lamin-specific chromatin interactions.. Nat Struct Mol Biol 32(10):1999-2011 PMID: 40750945
- 7. Larrieu D et al.. 2014. Chemical inhibition of NAT10 corrects defects of laminopathic cells.. Science 344(6183):527-32 PMID: 24786082
- 8. Shokrollahi M et al.. 2024. DNA double-strand break-capturing nuclear envelope tubules drive DNA repair.. Nat Struct Mol Biol 31(9):1319-1330 PMID: 38632359
