The Nuclear Lamina: Filament Architecture, Genome Attachment and Cell Function

1. Filaments and the surrounding interface

The lamina should be understood as part of an envelope-associated interface rather than an isolated uniform sheet. Turgay and colleagues resolved the molecular architecture of lamin filaments in a defined prepared somatic-cell system. Their findings identify thin filaments and their arrangement at the boundary, providing structural constraints for mechanical models. The filament dimensions in that specimen are not equivalent to the thickness of the entire live-cell lamina or a universal measure of nuclear stiffness. Membrane proteins, chromatin attachments and connections to other structures also contribute to how the boundary functions. [1] [6] [10]

A- and B-type lamin components must be distinguished from membrane proteins that connect them to chromatin or to the cytoskeleton. Molecular association gives candidate routes for coupling, while depletion and rescue experiments test functional contributions. The LINC-complex experiments of Crisp and colleagues showed SUN-dependent localization of nesprin 2 and a bridge across the perinuclear space. Lewis and colleagues examined different inner-membrane proteins as chromatin tethers. These interfaces can interact mechanically, but they address different connections: external force delivery and peripheral genome attachment are separate aspects of lamina-associated organization. [10] [6] [1]

2. Lamina-associated domains are a genomic association map

Guelen and colleagues mapped broad domains of lamina interaction in human fibroblasts, linking peripheral association to characteristic genomic and expression organization. The map changed the scale of the question from a few visible loci to genome-wide domain patterns. It nevertheless remains an association measurement in a specified cell population. A genomic interval assigned to a LAD is not thereby shown to remain attached at every instant in every cell, and a low-expression association does not establish that peripheral localization is the sole cause of its transcriptional state. [2]

The original study has a corrigendum correcting the identity of a chromatin-mark dataset and the provenance of Methods data. The corrected H3K9me3 information should accompany use of the paper. This editorial point matters because a genomic association can be interpreted differently if the underlying chromatin mark is mislabeled. The correction does not supply a new experiment on mechanical tethering, and its presence should not be used to infer changes beyond its stated scope. A lamina review should distinguish the primary mapping result, its corrected annotation and later mechanistic tests. [2] [11]

3. Current tethering evidence moves beyond lamin-centric models

Lewis and colleagues used combined depletion and genetic approaches to identify factors maintaining peripheral heterochromatin in mammalian cells. Their 2026 study implicated LBR and membrane-bound LAP2 isoforms as major redundant contributors, with rescue evidence supporting a functional tethering role. The response depended on the combination of envelope proteins perturbed. This is more precise than assuming that lamin A/C alone provides every heterochromatin attachment or that removing one candidate necessarily releases all peripheral chromatin. Redundancy is a biological mechanism that must be considered when interpreting a mild single-depletion phenotype. [6]

The same study separated immediate structural change from longer-term regulatory consequences. Short-term release of peripheral heterochromatin produced limited initial expression changes, whereas persistent loss was associated with broader chromatin and transcriptional effects. This temporal distinction prevents peripheral position from being equated with instantaneous, universal gene repression. It instead suggests that attachment helps maintain a nuclear organizational state whose consequences accumulate through chromatin and regulatory changes. Tests of causality should therefore follow the order of positioning, epigenetic and expression responses, rather than infer all of them from one endpoint image. [6] [2]

4. Lamins contribute to deformation-dependent mechanics

Lammerding and colleagues showed altered nuclear deformation and selected mechanotransduction responses in lamin-A/C-deficient mouse-cell models. Their work connects the genetic perturbation to a cellular mechanical phenotype under defined loading conditions. It does not demonstrate that every human LMNA variant produces the same phenotype or that surface-bead measurements constitute intranuclear particle rheology. Force transmission through the surrounding cell and mechanical resistance of the nucleus are related variables, and controls distinguishing them are essential to assign a nuclear contribution. [8]

Stephens and colleagues examined isolated nuclei and distinguished two response regimes: chromatin had a major contribution at smaller extensions, while lamin A supported strain stiffening at larger deformations. This result locates lamina function within a composite rather than making it the sole nuclear load-bearing material. An isolated-nucleus force–extension slope is geometry dependent and should not be presented as a universal elastic modulus. The biological interpretation is that lamin contributions become especially important when the nuclear boundary is extended sufficiently to recruit that response. [3] [1]

5. Chromatin attachments help transmit mechanical stress

Attar and colleagues used polymer modeling constrained by nuclear measurements to examine the relation between peripheral heterochromatin tethering and nuclear mechanical response. In their model, peripheral links allowed externally imposed forces to engage chromatin resistance. Internal chromatin interactions alone were insufficient when the network was not adequately coupled to the boundary. This is a mechanistic interpretation within the specified model, not a direct measurement of the strength or lifetime of every molecular tether. It nevertheless supplies a testable connection between lamina-associated organization and global force response. [7]

The implications can be tested by combining tether perturbation with mechanical measurements and chromatin-position mapping. A cell may retain lamin filaments yet lose an important chromatin connection, or retain a LAD association while altering the way forces are transmitted. Such conditions would distinguish the lamina’s filament properties from the contribution of its attachments. The optical-tweezer and imaging work of Bergamaschi and colleagues adds a route to observe internal organization while the nucleus is loaded. Joint assays are therefore needed to connect a specific attachment mechanism with a composite mechanical phenotype. [6] [7] [12]

6. Mechanical behavior also depends on nuclear activity

Metabolically active karyoplast experiments by Byfield and colleagues showed that energy dissipation and deformation could depend on ATP-related and BRM/BRG1-remodeling activity. This broadens lamina mechanics beyond a static filament shell by identifying internal active contributions. BRM-014 treatment has a dual target scope, which should remain explicit when interpreting the pharmacological result. The findings do not remove the role of lamins; they show that mechanical resistance and dissipation can change through the nuclear interior even when the experimental question is framed around whole-nucleus shape. [13] [3]

Frequency-dependent AFM comparisons by Pørtner and colleagues further distinguish nuclear preparation and loading rate. Live and isolated MCF7 nuclei showed related modulus spectra but differences in scale and loss tangent. Consequently, lamin-associated mechanical phenotypes should be tested under matched preparation and frequency conditions. A change observed in an isolated system may reveal an intrinsic nuclear contribution, whereas the same perturbation in a living cell additionally includes boundary support and cytoskeletal coupling. Neither setting should be treated as a universal replacement for the other. [14] [8] [10]

7. Human genetics establishes disease links, not one cellular explanation

Bonne and colleagues identified LMNA mutations associated with autosomal dominant Emery–Dreifuss muscular dystrophy in families. Eriksson and colleagues identified recurrent de-novo lamin-A mutations in classical Hutchinson–Gilford progeria, linking the common variant to altered splicing and a shortened protein product. These are primary genetic findings that establish disease associations and molecular consequences in their respective contexts. The observations do not alone decide whether a particular tissue phenotype is driven primarily by altered mechanics, gene regulation, protein processing or interactions among those routes. [4] [5]

A mechanistic account of laminopathy therefore needs to connect the specific variant with appropriate cell and tissue phenotypes. Null-cell experiments are informative but are not equivalent to every dominant missense or splice-altering mutation. Likewise, progeria-related defects should not be equated automatically with ordinary human aging. Similar nuclear shapes can arise through different molecular changes, and distinct tissues can expose different consequences of the same broadly expressed protein. The genetic result identifies the causal locus; it does not confer a single universal nuclear-mechanics signature or validate a treatment by itself. [4] [5] [8]

The genetic and mechanical evidence can be integrated through a sequence of experimentally distinct steps. First, the variant identifies the altered protein and its molecular consequence. Second, structural or localization assays determine whether filament organization or an associated interface changes. Third, force experiments quantify resistance under a relevant geometry. Finally, genome and expression measurements test regulatory consequences. This sequence does not require every laminopathy to traverse the same route, and it leaves room for interaction among mechanisms. Its advantage is to locate the observed defect before assigning it a tissue-level explanation. [4] [5] [1] [8] [6]

Human disease is also a reason to preserve cell-state specificity in comparisons. The same lamin-associated interface can support genome attachment in one state and become mechanically important under a different load. A phenotype established in cultured mouse null cells provides a defined perturbation; a dominant human variant supplies a different molecular condition. Directly comparing them requires showing which component and function are altered in common. Similar deformability or nuclear shape can guide a hypothesis, but variant-specific rescue and appropriately matched readouts are needed to establish the shared mechanism. [4] [5] [8] [3]

Current tether studies suggest another useful distinction: whether a regulatory phenotype follows loss of a physical attachment or a broader alteration in nuclear organization. Short-term and persistent perturbations can resolve that order. A direct tether-rescue that restores positioning before normalizing downstream expression would give different mechanistic information from a rescue that changes both simultaneously. Coupling such time courses to calibrated loading can further determine whether mechanical and regulatory changes share the same attachment requirement. This is a concrete way to test interaction between the lamina’s structural and genomic roles. [6] [7] [2]

8. Senescence, maintenance and acute failure are distinct

Freund and colleagues reported lamin-B1 loss as a senescence-associated biomarker in defined experimental models. This observation supports an association with a particular cellular state, rather than a standalone diagnosis of senescence in every cell or a universal biomarker of chronological age. Changes in lamina components can be considered alongside chromatin organization and other state markers, with the perturbation and lineage retained. A lamina measurement should specify whether it concerns expression, localization, filament architecture or a functional response, because these are not interchangeable readouts. [9] [1]

Acute envelope rupture during constrained migration supplies a different problem. Denais and colleagues observed compartmentalization loss and ESCRT-dependent recovery in defined cancer-cell migration systems. This is not the same event as gradual lamin-B1 reduction or long-term genome-tether loss. A deformed nucleus may remain intact, and reporter recovery after a rupture does not establish full restoration of genome function. Separating maintenance, acute failure and repair is necessary to understand how lamina-associated architecture protects a nucleus across both routine cell states and severe mechanical challenges. [15] [9] [6]

9. Matching lamina evidence to the claim

These distinctions guide experimental design. A hypothesis about genome attachment should include position and rescue readouts; a mechanical hypothesis should include calibrated loading and component perturbation; a disease hypothesis should preserve the variant and relevant lineage. Combining them can identify a route from altered attachment to force response and downstream function, but the route should be demonstrated rather than inferred from a shared change in nuclear shape. Current tethering and mechanical studies make such tests feasible by defining more specific molecular links. [6] [7] [12] [4] [5]

10. A current account of lamina function

The lamina contributes through filament architecture and its connections to membranes, chromatin and the cytoskeleton. Its physical effects depend on deformation, coupling and biological activity, while its genomic consequences depend on the duration and redundancy of attachment. Current evidence therefore favors describing a regulated interface with separable functions instead of a single structural or gene-silencing role. The next challenge is to connect specific lamin variants and tether components to matched structural, mechanical and regulatory measurements in relevant cell states. [1] [3] [6] [7] [13] [4] [5]

References

1. [1] Yagmur Turgay, Matthias Eibauer, Anne E. Goldman et al. (2017). The molecular architecture of lamins in somatic cells. Nature. 10.1038/nature21382
   Evidence and source scope

   Source type: primary. Access: Selected indexed primary main text (opening8000chars; not complete article), plus metadata..

   Prepared vimentin-null mouse-fibroblast lamina filament structure; approximately3.5nm filaments are not live-lamina thickness.

   No indexed notice in retrieved result is not a guarantee of no correction/retraction. New records lacked complete Scite notice check after monthly quota.

2. [2] Lars Guelen, Ludo Pagie, Émilie Brasset et al. (2008). Domain organization of human chromosomes revealed by mapping of nuclear lamina interactions. Nature. 10.1038/nature06947
   Evidence and source scope

   Source type: primary. Access: Primary abstract and bibliographic metadata; complete body unavailable through connector..

   LAD association map, domain scales and low expression in human fibroblasts; no universal permanent tether or repression causality.

   No indexed notice in retrieved result is not a guarantee of no correction/retraction. New records lacked complete Scite notice check after monthly quota.

3. [3] Andrew D. Stephens, Edward J. Banigan, Stephen A. Adam et al. (2017). Chromatin and lamin A determine two different mechanical response regimes of the cell nucleus. Molecular Biology of the Cell. 10.1091/mbc.E16-09-0653
   Evidence and source scope

   Source type: primary. Access: Primary abstract and bibliographic metadata; complete body unavailable through connector..

   Chromatin and lamins contribute in separate isolated-nucleus extension regimes; spring constants are not universal moduli or viscosity.

   No indexed notice in retrieved result is not a guarantee of no correction/retraction. New records lacked complete Scite notice check after monthly quota.

4. [4] Gisèle Bonne, Marina Raffaele di Barletta, Shaïda Varnous et al. (1999). Mutations in the gene encoding lamin A/C cause autosomal dominant Emery-Dreifuss muscular dystrophy. Nature Genetics. 10.1038/6799
   Evidence and source scope

   Source type: primary. Access: Primary abstract and bibliographic metadata; complete body unavailable through connector..

   Four LMNA variants co-segregated with EDMD in five families; genetics alone does not identify one mechanical defect.

   No indexed notice in retrieved result is not a guarantee of no correction/retraction. New records lacked complete Scite notice check after monthly quota.

5. [5] Maria Eriksson, William Ted Brown, Leslie B. Gordon et al. (2003). Recurrent de novo point mutations in lamin A cause Hutchinson–Gilford progeria syndrome. Nature. 10.1038/nature01629
   Evidence and source scope

   Source type: primary. Access: Primary abstract and bibliographic metadata; complete body unavailable through connector..

   Recurrent G608G in18/20 classical HGPS cases, cryptic splice consequence and50-amino-acid deletion; not ordinary-ageing equivalence.

   No indexed notice in retrieved result is not a guarantee of no correction/retraction. New records lacked complete Scite notice check after monthly quota.

6. [6] Renard Lewis, Virginia Sinigiani, Noura Maziak et al. (2026). LBR and LAP2 mediate heterochromatin tethering to the nuclear periphery to preserve genome homeostasis. Nature Cell Biology. 10.1038/s41556-025-01822-7
   Evidence and source scope

   Source type: primary. Access: Publisher primary Abstract and main Results through heterochromatin-tether deconvolution, membrane LAP2 rescue and short/long-term transcription effects read; complete Methods and supplements not appraised. Published 24 February 2026..

   Redundant LBR/membrane LAP2 tethering in mammalian cell models, distinction between short-term release and persistent loss; not universal instant repression by peripheral position.

   No independent experimental replication or raw-data reanalysis. Source interpretation confined to the stated access depth.

7. [7] A. G. Attar, J. Paturej, Ozan S. Sarıyer, E. Banigan, A. Erbaş (2025). Peripheral heterochromatin tethering is required for chromatin-based nuclear mechanical response. Nucleic Acids Research. 10.1093/nar/gkaf763
   Evidence and source scope

   Source type: primary. Access: Fetched Consensus primary abstract/record, cross-checked with SciSpace where available; complete body not appraised..

   Attar and colleagues used polymer simulations compared with micromechanical and chromosome-contact measurements. In that model, peripheral chromatin attachment transmitted imposed nuclear forces to chromatin, and internal crosslinks stiffened the nucleus only when that peripheral coupling was present. This is a model-constrained account of load transfer; a mapped lamina association by itself does not establish the strength or permanence of every molecular tether. Attar et al. (2025) .

   No indexed notice in retrieved result is not a guarantee of no correction/retraction. New records lacked complete Scite notice check after monthly quota.

8. [8] Jan Lammerding, Paul Christian Schulze, Tomosaburo Takahashi et al. (2004). Lamin A/C deficiency causes defective nuclear mechanics and mechanotransduction. Journal of Clinical Investigation. 10.1172/JCI19670
   Evidence and source scope

   Source type: primary. Access: Primary publisher main Abstract/selected Results and Methods, including cell strain and surface-bead controls, independently read; Scite truncated abstract insufficient alone..

   LaminA/C-null mouse-cell strain/deformation, viability and selected signaling; surface-bead cytoskeletal controls not intranuclear rheology.

   No indexed notice in retrieved result is not a guarantee of no correction/retraction. New records lacked complete Scite notice check after monthly quota.

9. [9] Adam Freund, Rémi-Martin Laberge, Marco Demaria et al. (2012). Lamin B1 loss is a senescence-associated biomarker. Molecular Biology of the Cell. 10.1091/mbc.E11-10-0884
   Evidence and source scope

   Source type: primary. Access: Selected indexed primary main text (opening8000chars; not complete article), plus metadata..

   LaminB1 decrease in defined fibroblast senescence states and irradiated-mouse tissue; no standalone individual-cell diagnosis or ordinary ageing equivalence.

   No indexed notice in retrieved result is not a guarantee of no correction/retraction. New records lacked complete Scite notice check after monthly quota.

10. [10] Melissa Crisp, Qian Liu, Kyle Roux et al. (2006). Coupling of the nucleus and cytoplasm: role of the LINC complex. Journal of Cell Biology. 10.1083/jcb.200509124
    Evidence and source scope

    Source type: primary. Access: Primary abstract and bibliographic identity through author institutional repository; full Methods not appraised..

    SUN1/SUN2–nesprin2 localization and depletion/overexpression in HeLa cells, perinuclear spacing and LINC model.

    No independent experimental replication or raw-data reanalysis. Source interpretation confined to the stated access depth.

11. [11] Lars Guelen, Ludo Pagie, Émilie Brasset et al. (2013). Correction: Corrigendum: Domain organization of human chromosomes revealed by mapping of nuclear lamina interactions. Nature. 10.1038/nature12316
    Evidence and source scope

    Source type: editorial notice. Access: Primary correction abstract/citation record containing full correction statements; original full Methods not reappraised..

    Official corrected H3K9me3 identity and Methods data sources; no inferred change to uncorrected abstract-level LAD conclusions.

    No indexed notice in retrieved result is not a guarantee of no correction/retraction. New records lacked complete Scite notice check after monthly quota.

12. [12] G. Bergamaschi, A. Biebricher, Hannes Witt, F. Byfield, Xamanie M R Seymonson, Cornelis Storm, P. Janmey, G. Wuite (2024). Heterogeneous force response of chromatin in isolated nuclei.. Cell Reports. 10.1016/j.celrep.2024.114852
    Evidence and source scope

    Source type: primary. Access: Fetched Consensus primary abstract/record, cross-checked with SciSpace where available; complete body not appraised..

    Bergamaschi and colleagues measured isolated-nucleus force responses together with chromatin and nuclear-envelope deformation. Chromatin was more compliant than the envelope below the reported 30% strain regime, and chromatin digestion softened nuclei. The joint readouts strengthen component interpretation in the tested preparation without defining one elastic modulus or viscosity for every nucleus. Bergamaschi et al. (2024) .

    No indexed notice in retrieved result is not a guarantee of no correction/retraction. New records lacked complete Scite notice check after monthly quota.

13. [13] Fitzroy J. Byfield, Behnaz Eftekhari, Kaeli Kaymak-Loveless et al. (2025). Metabolically intact nuclei are fluidized by the activity of the chromatin remodeling motor BRG1. Biophysical Journal. 10.1016/j.bpj.2024.11.3322
    Evidence and source scope

    Source type: primary. Access: Published PDF front matter, main preparation/treatment Methods, Results around Figure 9 and Discussion read; supplementary data not appraised..

    Metabolically active karyoplast compression/dissipation and BRM-014 inhibition; BRM-014 inhibits BRM and BRG1, so pharmacology is not exclusive genetic proof for BRG1. Karyoplasts are not bare detergent-isolated nuclei.

    No independent experimental replication or raw-data reanalysis. Source interpretation confined to the stated access depth.

14. [14] Ellen Juel Pørtner, Anna Mularski, Tobias William Jarrett, Stine Lauritzen Sønder, Jesper Nylandsted, Adam Cohen Simonsen (2025). Viscoelastic differences between isolated and live MCF7 cancer cell nuclei resolved with AFM microrheology. Journal of the Royal Society Interface. 10.1098/rsif.2024.0885
    Evidence and source scope

    Source type: primary. Access: Root independently read primary PMC12173521 Abstract and selected main Methods/Results paragraphs, including oscillatory preparation, hydrodynamic drag correction, morphology and Jeffreys analysis; primary Scite webpage identity corroborated. Supplement and raw-data reanalysis excluded..

    Oscillatory AFM on live and isolated MCF7 nuclei, hydrodynamic-drag validation, modulus/loss-tangent distinction and Jeffreys model. The published author list supersedes incomplete Consensus authors.

    No independent experimental replication or raw-data reanalysis. Source interpretation confined to the stated access depth.

15. [15] Céline Denais, Rachel M. Gilbert, Philipp Isermann et al. (2016). Nuclear envelope rupture and repair during cancer cell migration. Science. 10.1126/science.aad7297
    Evidence and source scope

    Source type: primary. Access: Primary author-manuscript main Abstract/Results pages1–4 and Figures1/2/4; supplementary Methods and raw data not reanalysed..

    NLS-reporter rupture, defined in-vitro and mouse-dermis models, deformation-associated damage foci and ESCRT-III-dependent resealing independently match primary main Results/Figures. Mixed-topic Scite opening excluded.

    No indexed notice in retrieved result is not a guarantee of no correction/retraction. New records lacked complete Scite notice check after monthly quota.

Evidence scope

This review integrates published primary research with a foundational methods review where needed. Source access ranges from primary abstracts to the selected main Results and Methods identified in each reference record. It is a scholarly synthesis rather than an independent reanalysis of experimental data. Conclusions retain the biological system, measurement scale and model assumptions of the cited studies.