GO:0017056 structural constituent of nuclear pore: Mechanism, Genes and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0017056 (structural constituent of nuclear pore) is a molecular function describing the contribution of a molecule to the structural integrity of the nuclear pore complex (NPC), a protein-lined channel in the nuclear envelope.
• The NPC is a massive multiprotein assembly that mediates nucleocytoplasmic transport of macromolecules and is built from nucleoporins (Nups) organized into scaffold, linker, and barrier subcomplexes.
• Structural nucleoporins such as NUP107, NUP133, NUP155, NUP93, and NUP205 form the architectural core of the NPC and are essential for its assembly and stability.
• Mutations in nucleoporin genes are linked to human diseases including cancers, leukemias, and neurodevelopmental disorders, making GO:0017056 a relevant functional node for disease research.
• CRISPR-based knockout, point-mutation, knock-in, and overexpression models enable causal testing of nucleoporin gene function in NPC structure and transport.
• Studying GO:0017056 requires integrated structural, biochemical, and imaging methods such as cryo-ET, mass spectrometry, and live-cell fluorescence microscopy.
Description
The nuclear pore complex (NPC) is a large proteinaceous channel embedded in the nuclear envelope that governs the exchange of macromolecules between the nucleus and the cytoplasm. The molecular function defined by GO:0017056, structural constituent of nuclear pore, captures the contribution of individual proteins to the architectural integrity of this channel. This function is distinct from transport activity: it specifically refers to the structural role that nucleoporins play in building and maintaining the NPC scaffold and permeability barrier. Understanding GO:0017056 is therefore central to dissecting how the NPC is assembled, how it maintains its selective barrier, and how its dysfunction contributes to disease. Nucleoporins (Nups) are the proteins that carry this structural function. They are organized into distinct subcomplexes, including the Y-complex (NUP107-NUP160), the inner ring complex (NUP93-NUP205), and the central channel FG-Nups that form the permeability barrier. Structural nucleoporins provide the scaffold that positions FG-Nups and anchors the NPC within the nuclear envelope. Because the NPC is one of the largest macromolecular machines in the cell, its assembly and maintenance require coordinated expression and stoichiometric assembly of many structural components. For researchers, GO:0017056 provides a functional annotation that links genes to the structural core of the NPC. This is important because mutations in nucleoporin genes are increasingly recognized in human disease, including cancer and developmental disorders. Moreover, the NPC is a dynamic structure whose composition changes during differentiation and in response to cellular stress. Studying GO:0017056 therefore bridges cell biology, structural biology, and disease genetics, and it benefits from CRISPR-based models that allow precise perturbation of individual nucleoporin genes.
structural constituent of nuclear pore At A Glance
| GO ID | GO:0017056 |
|---|---|
| GO term | structural constituent of nuclear pore |
| Ontology | molecular_function |
| Synonym | nuclear pore activity; nucleocytoplasmic transporter activity |
| Definition | The action of a molecule that contributes to the structural integrity of the nuclear pore complex, a protein-lined channel in the nuclear envelope that allows the transfer of macromolecules. |
| Major function | Provides structural integrity to the nuclear pore complex, enabling its role as a selective channel for nucleocytoplasmic transport. |
| Cellular location | Nuclear envelope; nuclear pore complex. |
| Representative proteins | NUP107, NUP133, NUP155, NUP93, NUP205, NUP160, NUP85, NUP96, NUP43, NUP37, SEH1L, and other nucleoporins. |
| Related processes | Nuclear pore assembly, nucleocytoplasmic transport, chromatin organization, cell cycle regulation. |
What Is GO:0017056?
GO:0017056, structural constituent of nuclear pore, is a molecular function term defined as the action of a molecule that contributes to the structural integrity of the nuclear pore complex, a protein-lined channel in the nuclear envelope that allows the transfer of macromolecules. In other words, a gene product annotated with this term is part of the physical architecture of the NPC, helping to build, stabilize, or organize the channel rather than directly catalyzing a chemical reaction or acting as a transporter. This function is typically associated with scaffold nucleoporins that form the core framework of the NPC and with components that establish the permeability barrier.
Why Is structural constituent of nuclear pore Important in Cell Biology?
GO:0017056 is important because the nuclear pore complex is the sole gateway for nucleocytoplasmic exchange of macromolecules, and its structural integrity is essential for gene expression, cell division, and signaling. Structural nucleoporins are not merely passive building blocks; they contribute to the permeability barrier and provide binding sites that regulate transport and chromatin organization. Mutations in nucleoporin genes can disrupt NPC structure and cause human diseases, including cancers and neurodevelopmental disorders. Therefore, understanding the molecular function of structural constituent of nuclear pore is critical for both basic cell biology and translational research.
• The NPC is the primary channel for nucleocytoplasmic transport, and its structural components are essential for mRNA export and protein import.
• Structural nucleoporins maintain the permeability barrier that prevents free diffusion of macromolecules between nucleus and cytoplasm.
• Nucleoporin mutations are associated with hematological malignancies and solid tumors, linking GO:0017056 to cancer biology.
• The NPC scaffold is dynamically remodeled during mitosis and differentiation, requiring regulated expression of structural nucleoporins.
• Structural nucleoporins contribute to chromatin organization and gene regulation, extending their roles beyond transport.
• Evolutionary divergence of nucleoporins from fungi to metazoans highlights species-specific structural adaptations relevant to model organism choice.
• Cryo-electron tomography and integrative modeling have revealed the architecture of the linker-scaffold, providing a framework for understanding GO:0017056.
• CRISPR screens can identify nucleoporin genes required for NPC function and cell fitness, enabling functional annotation of GO:0017056.
• Defects in NPC structure are implicated in aging and neurodegenerative diseases, making this term relevant to aging research.
• Targeting structural nucleoporins with genetic tools can reveal their non-transport roles in cell cycle and development.
What Happens During structural constituent of nuclear pore?
Assembly of the nuclear pore scaffold
In simple terms: Cells build the nuclear pore by assembling many protein building blocks into a stable ring-like structure.
The nuclear pore complex is assembled from multiple copies of nucleoporins that form distinct subcomplexes, including the Y-complex and inner ring complex. Structural nucleoporins such as NUP107, NUP133, NUP160, NUP85, NUP96, NUP43, NUP37, and SEH1L form the outer rings, while NUP93, NUP205, NUP155, and NUP188 form the inner rings. These proteins interact in a defined stoichiometry to create a scaffold that anchors the NPC in the nuclear envelope. The assembly process is thought to begin with the Y-complex at the nuclear envelope and proceed through sequential recruitment of inner ring and central channel components.
Formation of the permeability barrier
In simple terms: The center of the pore is filled with flexible proteins that act like a sieve, letting small molecules pass but blocking large ones.
The central channel of the NPC contains FG-nucleoporins, which are rich in phenylalanine-glycine repeats and form a selective permeability barrier. These FG-Nups are anchored by structural nucleoporins and create a meshwork that allows rapid diffusion of small molecules while restricting larger macromolecules. The structural integrity provided by scaffold nucleoporins is essential for positioning FG-Nups correctly and maintaining the barrier. Biophysical studies suggest that the barrier properties arise from cohesive interactions among FG repeats and their interactions with transport receptors.
Anchoring to the nuclear envelope
In simple terms: The pore must be firmly attached to the membrane surrounding the nucleus so it does not fall out.
Structural nucleoporins interact with transmembrane nucleoporins such as NDC1, POM121, and GP210 to anchor the NPC within the nuclear envelope. The linker-scaffold architecture connects the inner and outer rings and provides attachment points for the membrane. This anchoring is critical for maintaining the position and stability of the NPC during interphase and for coordinating NPC assembly with nuclear envelope expansion.
Dynamic remodeling during cell division
In simple terms: When a cell divides, the nuclear pore disassembles and reassembles, requiring careful regulation of its structural proteins.
During mitosis, the nuclear envelope breaks down and the NPC disassembles into subcomplexes. Structural nucleoporins are phosphorylated and redistributed, and they reassemble around chromatin after mitosis. This dynamic remodeling requires precise regulation of nucleoporin availability and interactions. The structural function of nucleoporins is therefore not static but is tightly coupled to the cell cycle.
Integration with chromatin and gene regulation
In simple terms: Some nuclear pore proteins also help organize DNA and control which genes are active.
Beyond their structural role, nucleoporins can interact with chromatin and influence gene expression. For example, NUP98 forms fusion proteins in leukemia that alter chromatin state and transcription. Structural nucleoporins may also contribute to the spatial organization of the genome at the nuclear periphery. These functions highlight that GO:0017056 can have downstream effects on gene regulation.
Key Genes Involved in GO:0017056 structural constituent of nuclear pore
The following genes encode proteins that carry or are closely associated with the structural constituent of nuclear pore function, based on published literature.
| Gene | Major Role | Research Relevance |
|---|---|---|
| NUP107 | Y-complex scaffold nucleoporin | Essential for NPC assembly; knockout causes NPC clustering and transport defects |
| NUP133 | Y-complex scaffold nucleoporin | Mutations linked to developmental disorders; used in structural studies |
| NUP160 | Y-complex scaffold nucleoporin | Required for mRNA export; knockout affects cell viability |
| NUP155 | Inner ring scaffold nucleoporin | Mutations cause atrial fibrillation; involved in NPC stability |
| NUP93 | Inner ring scaffold nucleoporin | Mutations linked to nephrotic syndrome; key for NPC assembly |
| NUP205 | Inner ring scaffold nucleoporin | Required for NPC integrity; studied in cryo-ET models |
| NUP188 | Inner ring scaffold nucleoporin | Contributes to NPC architecture; potential disease relevance |
| NUP85 | Y-complex scaffold nucleoporin | Involved in NPC assembly and mRNA export |
| NUP96 | Y-complex scaffold nucleoporin | Also involved in immune signaling; knockout affects NPC structure |
| NUP43 | Y-complex scaffold nucleoporin | Structural component; studied in evolutionary comparisons |
| NUP37 | Y-complex scaffold nucleoporin | Required for NPC assembly; potential cancer relevance |
| SEH1L | Y-complex scaffold nucleoporin | Structural role in NPC; linked to mTOR signaling |
| NUP98 | FG-nucleoporin with structural and regulatory roles | Fusion proteins in leukemia; chromatin regulation |
| NUP153 | FG-nucleoporin at nuclear basket | Involved in mRNA export and chromatin organization |
| NUP50 | Nuclear basket nucleoporin | Regulates transport and gene expression |
| TPR | Nuclear basket structural protein | Required for mRNA export and chromatin organization |
| POM121 | Transmembrane nucleoporin | Anchors NPC to nuclear envelope; essential for assembly |
| NDC1 | Transmembrane nucleoporin | Links NPC to nuclear envelope; knockout affects NPC distribution |
How Is structural constituent of nuclear pore Regulated?
The expression and assembly of structural nucleoporins are regulated at multiple levels. During the cell cycle, nucleoporin phosphorylation controls NPC disassembly and reassembly. The mTOR signaling pathway has been linked to nucleoporin function, particularly through SEH1L and the SEA complex. Additionally, nucleoporin levels can be regulated by transcription factors and by proteostasis mechanisms that ensure stoichiometric assembly. In response to cellular stress, nucleoporin expression and NPC composition can change, affecting transport and gene expression. These regulatory mechanisms ensure that the structural constituent of nuclear pore function is adapted to cell state and environmental cues.
structural constituent of nuclear pore and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| NUP98 | Acute myeloid leukemia; chromatin dysregulation | Knock-in of NUP98-HOXA9 fusion in hematopoietic cells; knockout in cell lines |
| NUP93 | Steroid-resistant nephrotic syndrome | Knockout in podocyte-like cells; point mutation knock-in |
| NUP155 | Atrial fibrillation; cardiac dysfunction | Knockout in cardiomyocytes; knock-in of patient mutations |
| NUP107 | Neurodevelopmental disorders; NPC assembly defects | Knockout in neural progenitor cells; rescue with wild-type or mutant |
| NUP133 | Developmental disorders; NPC clustering | Knockout in fibroblasts; live-cell imaging of NPC |
Nucleoporin mutations in cancer
Mutations and chromosomal translocations involving nucleoporin genes are found in various cancers, particularly leukemias. NUP98 fusions with homeodomain genes such as HOXA9 or NSD1 drive aggressive leukemias by altering chromatin state and gene expression. Other nucleoporins, including NUP214 and NUP88, are also implicated in hematological malignancies. These findings suggest that structural nucleoporins can contribute to oncogenesis through both structural and regulatory mechanisms.
Neurodevelopmental and neurodegenerative disorders
Mutations in nucleoporin genes such as NUP107, NUP133, and NUP155 have been linked to neurodevelopmental disorders and cardiac arrhythmias. In neurodegeneration, defects in NPC structure and nucleocytoplasmic transport are observed in amyotrophic lateral sclerosis and frontotemporal dementia. The structural integrity of the NPC is essential for neuronal function, and its disruption may contribute to disease pathogenesis.
Nephrotic syndrome and kidney disease
Mutations in NUP93, NUP205, and NUP160 have been identified in patients with steroid-resistant nephrotic syndrome. These mutations affect NPC assembly and permeability, leading to podocyte dysfunction. This highlights the importance of structural nucleoporins in tissue-specific diseases.
Viral infections and immune evasion
Many viruses interact with nucleoporins to manipulate nucleocytoplasmic transport and evade immune responses. For example, viral proteins can bind to NUP98 or NUP153 to disrupt mRNA export and host gene expression. Understanding the structural role of nucleoporins may inform antiviral strategies.
From structural constituent of nuclear pore-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does loss of a nucleoporin gene disrupt NPC structure? | CRISPR knockout in HeLa or HEK293T cells followed by immunofluorescence and cryo-ET |
| Does a patient mutation affect NPC assembly? | Point-mutation knock-in using CRISPR in patient-derived fibroblasts or iPSCs |
| Can a tagged nucleoporin rescue NPC function? | Knock-in of GFP- or HA-tagged nucleoporin at endogenous locus |
| Does overexpression of a nucleoporin alter NPC composition? | Doxycycline-inducible overexpression in stable cell lines |
| Which nucleoporins are essential for cell fitness? | Genome-wide CRISPR knockout library screening with next-generation sequencing |
| How does a nucleoporin mutation affect mRNA export? | Knockout or knock-in cells followed by RNA-seq and single-molecule FISH |
How to Study the structural constituent of nuclear pore Process
| Method | What It Measures | Typical Application |
|---|---|---|
| Cryo-electron tomography | 3D architecture of NPC scaffold | Determining structural organization of nucleoporins |
| Integrative modeling | Fits protein structures into cryo-ET maps | Building atomic models of NPC subcomplexes |
| AP-MS | Protein-protein interactions | Identifying nucleoporin subcomplex components |
| BioID proximity labeling | Proximity interactome in live cells | Mapping nucleoporin interactions |
| Live-cell fluorescence microscopy | NPC localization and dynamics | Assessing knockout or knock-in effects |
| FRAP | Protein turnover at NPC | Measuring nucleoporin exchange rates |
| RNA-seq | Transcriptome changes | Evaluating mRNA export defects after nucleoporin perturbation |
| CRISPR knockout screen | Gene essentiality and fitness | Identifying nucleoporins required for cell viability |
Structural biology methods
Cryo-electron tomography (cryo-ET) and integrative modeling have been used to determine the architecture of the NPC scaffold and linker regions. These methods provide near-atomic resolution maps of nucleoporin complexes and reveal how structural nucleoporins interact. Negative-stain electron microscopy and X-ray crystallography of nucleoporin subcomplexes complement these approaches.
Proteomics and interactomics
Affinity purification coupled with mass spectrometry (AP-MS) can identify interaction partners of structural nucleoporins and define subcomplex composition. Proximity labeling methods such as BioID can map the nucleoporin interactome in living cells. These approaches help assign genes to GO:0017056 by demonstrating physical association with the NPC.
Imaging and live-cell assays
Fluorescence microscopy of GFP-tagged nucleoporins allows visualization of NPC assembly and distribution in real time. Super-resolution microscopy can resolve individual NPCs and quantify their density. Fluorescence recovery after photobleaching (FRAP) measures nucleoporin dynamics at the pore.
Functional genomics and transport assays
CRISPR knockout screens combined with RNA-seq can identify nucleoporin genes required for cell growth and mRNA export. Nuclear import and export assays using reporter proteins measure the functional consequences of structural nucleoporin perturbations. Single-molecule imaging can quantify transport kinetics through individual NPCs.
How CRISPR Can Be Used to Study GO:0017056 structural constituent of nuclear pore
Knockout
CRISPR knockout of structural nucleoporin genes such as NUP107, NUP93, or NUP205 can disrupt NPC assembly and cause cell lethality or growth defects. Knockout cell lines are valuable for studying the structural role of individual nucleoporins and for identifying compensatory mechanisms. However, because many nucleoporins are essential, inducible knockout systems are often used to control timing.
Point Mutation
Point mutations identified in patients, such as those in NUP93 or NUP155, can be introduced into endogenous loci using CRISPR base editing or homology-directed repair. These models allow researchers to test whether specific amino acid changes affect NPC structure and function without confounding effects of complete loss. Point-mutation knock-in cells are useful for dissecting structure-function relationships.
Knock-in
Knock-in of epitope tags (e.g., GFP, HA, or FLAG) at endogenous nucleoporin loci enables visualization and biochemical purification of NPC components. Tagged knock-in cell lines can be used for live-cell imaging, immunoprecipitation, and proteomics. This approach preserves endogenous regulation and stoichiometry.
Overexpression
Overexpression of wild-type or mutant nucleoporins can reveal dominant-negative effects or alterations in NPC composition. Inducible overexpression systems allow controlled expression levels and timing. Overexpression models are particularly useful for studying nucleoporin fusions, such as NUP98-HOXA9, that drive leukemia.
How EDITGENE Supports structural constituent of nuclear pore Research
Researchers studying structural constituent of nuclear pore-related genes often need to determine whether a candidate gene is causally involved in NPC structure, transport, or disease. EDITGENE provides a comprehensive suite of CRISPR-based services to generate precisely engineered cell models, enabling functional validation of nucleoporin genes and their variants.
Contact EDITGENE today to design your custom CRISPR model for structural constituent of nuclear pore research.
Frequently Asked Questions About structural constituent of nuclear pore
What is GO:0017056 structural constituent of nuclear pore?
GO:0017056 is a molecular function term describing the contribution of a protein to the structural integrity of the nuclear pore complex, a channel in the nuclear envelope that allows macromolecule transfer.
What genes are involved in structural constituent of nuclear pore?
Genes encoding nucleoporins such as NUP107, NUP133, NUP155, NUP93, NUP205, NUP160, NUP85, NUP96, NUP43, NUP37, SEH1L, and others carry this function.
What is the function of the nuclear pore complex?
The nuclear pore complex mediates nucleocytoplasmic transport of macromolecules and provides a selective barrier between the nucleus and cytoplasm.
How is the nuclear pore complex assembled?
The NPC is assembled from multiple nucleoporin subcomplexes, including the Y-complex and inner ring complex, which form a scaffold anchored in the nuclear envelope.
What diseases are linked to nucleoporin mutations?
Nucleoporin mutations are linked to cancers such as leukemia, neurodevelopmental disorders, nephrotic syndrome, and cardiac arrhythmias.
What methods are used to study structural constituent of nuclear pore?
Methods include cryo-electron tomography, integrative modeling, AP-MS, live-cell imaging, FRAP, RNA-seq, and CRISPR screens.
How can CRISPR be used to study nucleoporin genes?
CRISPR can generate knockout, point-mutation knock-in, tagged knock-in, and overexpression models to test nucleoporin function and disease variants.
What is the permeability barrier of the nuclear pore?
The permeability barrier is formed by FG-nucleoporins in the central channel, which allow small molecules to pass while restricting larger macromolecules.
Are nucleoporins involved in gene regulation?
Yes, some nucleoporins interact with chromatin and influence gene expression, as seen with NUP98 fusions in leukemia.
How do nucleoporins differ between species?
Nucleoporin composition and sequence diverge from fungi to metazoans, with species-specific adaptations in NPC structure.
Conclusion
GO:0017056 structural constituent of nuclear pore defines the architectural role of nucleoporins in building and maintaining the nuclear pore complex. This function is essential for nucleocytoplasmic transport, cell division, and gene regulation, and its disruption is linked to a growing list of human diseases. Advances in structural biology and CRISPR-based models continue to illuminate how individual nucleoporins contribute to NPC integrity and function. Researchers can leverage these tools to dissect the molecular mechanisms of GO:0017056 and to develop therapeutic strategies targeting NPC dysfunction.
References
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