GO:1990254 keratin filament binding: Mechanism, Genes and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:1990254 keratin filament binding is a molecular function defined as binding to a keratin filament, an intermediate filament composed of acidic and basic keratins (types I and II), typically expressed in epithelial cells.
• Keratin filaments are dynamic cytoskeletal polymers whose assembly and disassembly are regulated by associated proteins and post-translational modifications.
• Trichoplein was identified as a novel keratin filament-binding protein that localizes to keratin filaments and may regulate their organization.
• 14-3-3 proteins bind keratins and modulate keratin filament dynamics, influencing hepatocyte mitotic progression.
• Mutations in keratin genes or keratin-binding partners can disrupt filament networks, leading to diseases such as epidermolysis bullosa simplex and liver injury [2,6].
• Studying keratin filament binding requires integrated approaches including CRISPR knockout, point mutations, knock-in reporters, and biochemical assays [2,5,7].
Description
Keratin filaments are intermediate filaments that provide mechanical stability to epithelial cells. The molecular function of keratin filament binding (GO:1990254) refers to the selective interaction of proteins with these filaments, a process critical for cytoskeletal organization and cellular resilience. This function is mediated by diverse proteins that recognize keratin filaments and regulate their assembly, dynamics, and turnover [5,7]. Understanding keratin filament binding is essential because defects in this interaction contribute to a range of human pathologies, from skin blistering to liver disease [2,6]. Researchers study this function to uncover how cells maintain structural integrity and respond to stress, and to identify therapeutic targets for related disorders [2,6].
keratin filament binding At A Glance
| GO ID | GO:1990254 |
|---|---|
| GO term | keratin filament binding |
| Ontology | molecular_function |
| Synonym | none |
| Major function | Binding to keratin filaments, intermediate filaments composed of type I and type II keratins |
| Definition source | QuickGO |
| Related cellular component | Keratin filament (GO:0045095) |
| Related biological process | Intermediate filament organization (GO:0045109) |
What Is GO:1990254?
GO:1990254 keratin filament binding is a molecular function term describing the binding to a keratin filament, which is an intermediate filament composed of acidic and basic keratins (types I and II), typically expressed in epithelial cells. This binding event is non-covalent and specific to keratin polymers, distinguishing it from general protein-protein interactions.
Why Is keratin filament binding Important in Cell Biology?
Keratin filament binding is fundamental to epithelial cell mechanics and signaling. Proteins that bind keratin filaments can modulate filament assembly, stability, and interactions with other cytoskeletal elements, thereby influencing cell shape, migration, and survival [4,5]. Dysregulation of these interactions is linked to diseases such as epidermolysis bullosa simplex, where keratin mutations cause filament aggregation and skin fragility, and to liver injury where keratin filament disruption exacerbates hepatocyte damage. Thus, understanding keratin filament binding offers insights into disease mechanisms and potential therapeutic strategies.
• Maintains epithelial cell integrity by anchoring keratin filaments to desmosomes and hemidesmosomes.
• Regulates keratin filament dynamics during mitosis, as shown for 14-3-3 proteins in hepatocytes.
• Mutations in keratin genes or binding partners cause skin blistering diseases like epidermolysis bullosa simplex.
• Keratin filament disruption is associated with liver injury and steatohepatitis.
• Trichoplein, a keratin filament-binding protein, may link keratin filaments to other cellular structures.
• Autoantibodies against keratin filaments are found in autoimmune conditions, indicating their immunogenicity.
• Keratin filament binding proteins can serve as diagnostic markers in synovial sarcoma.
• Targeting keratin filament binding may offer therapeutic avenues for epithelial cancers and genetic skin disorders [2,6].
Molecular Mechanism of keratin filament binding
Recognition of Keratin Filaments
In simple terms: Proteins that bind keratin filaments first need to recognize and attach to the filament surface.
Keratin filaments are composed of type I and type II keratin heteropolymers that assemble into 10-nm intermediate filaments. Binding proteins typically interact with specific surface epitopes on the filament, which may be exposed in a phosphorylation-dependent manner. For example, 14-3-3 proteins bind to keratin 18 in a phosphorylation-dependent manner, modulating filament solubility and organization.
Structural Features of Binding Proteins
In simple terms: The binding proteins have special domains that allow them to grip the keratin filament.
Many keratin filament-binding proteins contain coiled-coil domains or specific binding motifs that mediate interaction with keratin filaments. Trichoplein, for instance, was identified as a novel keratin filament-binding protein with a coiled-coil domain that localizes to keratin filaments. The structural basis of these interactions is an active area of research, with recent insights into intermediate filament structure informing binding models.
Regulation by Phosphorylation
In simple terms: Chemical tags like phosphate groups can switch binding on or off.
Phosphorylation of keratins or their binding partners regulates filament binding. 14-3-3 proteins bind to phosphorylated keratin 18, and this interaction modulates keratin filament dynamics during mitosis. Similarly, PKC412, a kinase inhibitor, normalizes mutation-related keratin filament disruption by promoting keratin-myosin binding, indicating that signaling pathways can influence filament interactions.
Functional Consequences of Binding
In simple terms: Once bound, these proteins can change how the filament behaves or connects to other cell parts.
Binding of proteins to keratin filaments can alter filament assembly, stability, and interactions with other cytoskeletal components. For example, 14-3-3 binding to keratins affects hepatocyte mitotic progression, suggesting a role in cell cycle regulation. Trichoplein may link keratin filaments to other structures, contributing to cytoskeletal crosstalk. Disruption of these interactions can lead to filament aggregation and disease.
Key Genes Involved in GO:1990254 keratin filament binding
The following genes encode proteins that bind keratin filaments or are keratins themselves, with relevance to research on GO:1990254.
| Gene | Major Role | Research Relevance |
|---|---|---|
| KRT5 | Type II keratin, forms heteropolymers with type I keratins | Mutations cause epidermolysis bullosa simplex; model for filament binding studies |
| KRT14 | Type I keratin, partner of KRT5 in basal keratinocytes | Mutations cause epidermolysis bullosa simplex; target for gene editing |
| KRT8 | Type II keratin, expressed in simple epithelia | Phosphorylation regulates binding to 14-3-3 proteins |
| KRT18 | Type I keratin, partner of KRT8 | Binds 14-3-3 proteins; involved in liver disease |
| TCHP | Trichoplein, keratin filament-binding protein | Regulates keratin filament organization; potential tumor suppressor |
| YWHAB | 14-3-3 beta, binds phosphorylated keratins | Modulates keratin filament dynamics and mitosis |
| YWHAG | 14-3-3 gamma, binds keratins | Involved in keratin filament regulation |
| HMCN1 | Hemicentin-1, extracellular matrix protein | Variants aggravate epidermolysis bullosa simplex phenotype |
| PKC | Protein kinase C, phosphorylates keratins | Inhibitor PKC412 normalizes keratin filament disruption |
| MYH9 | Myosin heavy chain 9, interacts with keratins | Keratin-myosin binding promoted by PKC412 |
| VCL | Vinculin, links keratins to focal adhesions | Potential keratin filament binding partner |
| DSP | Desmoplakin, links keratin filaments to desmosomes | Keratin filament binding protein in desmosomes |
| JUP | Plakoglobin, desmosomal protein | Interacts with keratin filaments |
| PKP1 | Plakophilin-1, desmosomal protein | Binds keratin filaments |
| KRT1 | Type II keratin, suprabasal epidermis | Mutations cause epidermolytic hyperkeratosis |
| KRT10 | Type I keratin, partner of KRT1 | Mutations cause epidermolytic hyperkeratosis |
| KRT6A | Type II keratin, induced in stress | Mutations cause pachyonychia congenita |
| KRT16 | Type I keratin, partner of KRT6A | Mutations cause pachyonychia congenita |
How Is keratin filament binding Regulated?
Keratin filament binding is regulated by post-translational modifications, particularly phosphorylation. 14-3-3 proteins bind to keratin 18 in a phosphorylation-dependent manner, and this interaction modulates keratin filament dynamics and hepatocyte mitotic progression. Additionally, PKC412, a kinase inhibitor, promotes keratin-myosin binding and normalizes mutation-related keratin filament disruption in mice, indicating that kinase signaling pathways regulate filament interactions. These findings highlight that keratin filament binding is not constitutive but dynamically controlled by cellular signaling.
keratin filament binding and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| KRT5 | Epidermolysis bullosa simplex | Knockout or point-mutation in keratinocytes; skin organoids |
| KRT14 | Epidermolysis bullosa simplex | CRISPR knock-in of patient mutations in cell lines |
| KRT8/KRT18 | Liver disease, steatohepatitis | Knockout mice or hepatocyte cell lines [2,7] |
| TCHP | Cancer, cytoskeletal organization | Overexpression or knockout in cancer cell lines |
| HMCN1 | Epidermolysis bullosa simplex modifier | Knock-in mouse models |
Epidermolysis Bullosa Simplex
Epidermolysis bullosa simplex (EBS) is a skin blistering disorder often caused by mutations in KRT5 or KRT14, which disrupt keratin filament assembly and binding interactions. Recent studies show that HMCN1 variants can aggravate the EBS phenotype, suggesting that extracellular matrix components influence keratin filament stability. Understanding keratin filament binding is crucial for developing therapies that restore filament integrity.
Liver Disease
Keratin filaments in hepatocytes are composed of KRT8 and KRT18. Mutations in these keratins or disruption of their binding partners lead to liver injury and steatohepatitis. PKC412 normalizes mutation-related keratin filament disruption by promoting keratin-myosin binding, highlighting a potential therapeutic strategy. 14-3-3 proteins also modulate keratin filaments and hepatocyte mitotic progression, linking keratin binding to liver regeneration.
Cancer
Keratin filaments are widely used as tumor markers, and their binding partners may influence cancer progression. For example, trichoplein, a keratin filament-binding protein, is downregulated in some cancers and may act as a tumor suppressor. Synovial sarcoma, a soft tissue tumor, can be misdiagnosed due to keratin expression, underscoring the importance of keratin filament biology in cancer diagnostics.
From keratin filament binding-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does loss of a candidate gene disrupt keratin filament binding? | CRISPR knockout cell line (e.g., keratinocytes) |
| Does a specific point mutation in a keratin gene alter filament binding? | Point-mutation knock-in via CRISPR |
| Where does a keratin-binding protein localize in live cells? | Tagged knock-in (e.g., GFP) |
| Does overexpression of a binding protein stabilize keratin filaments? | Overexpression cell line |
| Can a drug normalize mutant keratin filament disruption? | Mouse model with mutation, treated with PKC412 |
| How does phosphorylation regulate keratin binding? | Phospho-mimetic or phospho-deficient mutants |
How to Study the keratin filament binding Process
| Method | What It Measures | Typical Application |
|---|---|---|
| Co-sedimentation assay | Binding of proteins to keratin filaments | In vitro validation of direct binding |
| Immunofluorescence | Colocalization with keratin filaments | Cellular localization studies |
| Live-cell imaging | Dynamic interactions with keratin filaments | Real-time binding dynamics |
| CRISPR knockout | Loss-of-function effects on filament binding | Functional studies of candidate genes |
| CRISPR knock-in | Effects of specific mutations on binding | Disease modeling |
| Mass spectrometry | Identification of binding partners | Interactome discovery |
| Phospho-specific antibodies | Phosphorylation-dependent binding | Regulation studies |
| Drug treatment assays | Modulation of filament binding | Therapeutic testing |
Biochemical Binding Assays
In vitro binding assays such as co-sedimentation, pull-down, and surface plasmon resonance can measure direct interactions between candidate proteins and keratin filaments. These assays use purified keratins or filament aggregates to quantify binding affinity and specificity.
Imaging and Colocalization
Fluorescence microscopy, including immunofluorescence and live-cell imaging with tagged proteins, allows visualization of keratin filament binding in cells. Colocalization with keratin filaments confirms binding in situ, and time-lapse imaging can reveal dynamic interactions.
Genetic Perturbation with CRISPR
CRISPR knockout, point mutation, and knock-in models enable functional studies of keratin filament binding. For example, knocking out TCHP can reveal its role in filament organization, while introducing patient mutations in KRT5 or KRT14 mimics disease phenotypes.
Proteomics and Interactomics
Mass spectrometry-based proteomics can identify novel keratin filament-binding proteins from cell lysates or tissues. Proximity labeling or co-immunoprecipitation coupled with mass spectrometry can map the keratin interactome.
How CRISPR Can Be Used to Study GO:1990254 keratin filament binding
Knockout
CRISPR knockout of genes encoding keratin filament-binding proteins or keratins themselves can reveal their essential roles in filament organization and cell integrity. For example, knocking out TCHP in epithelial cells can test its function in keratin filament binding and cytoskeletal crosstalk.
Point Mutation
Introducing disease-associated point mutations into keratin genes (e.g., KRT5 or KRT14) using CRISPR base editing or homology-directed repair can model epidermolysis bullosa simplex and assess how mutations affect filament binding.
Knock-in
Knock-in of tagged versions of keratin-binding proteins (e.g., GFP-TCHP) allows real-time visualization of binding dynamics and localization in live cells. Knock-in of patient mutations can also create isogenic disease models.
Overexpression
Overexpression of wild-type or mutant keratin filament-binding proteins can test gain-of-function effects on filament stability and cellular phenotype. For instance, overexpressing trichoplein may alter keratin filament organization.
How EDITGENE Supports keratin filament binding Research
Researchers studying keratin filament binding-related genes often need to determine whether a candidate gene is causally involved in filament regulation, disease pathogenesis, or cellular stress responses. EDITGENE provides comprehensive CRISPR-based services to accelerate this research.
Contact EDITGENE today to design your custom CRISPR model for keratin filament binding research.
Related Products
| Product name | Cat.No. | Species | Gene ID | |
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| SIRT1 Knockout HEK293 Cell Line | EDJ-KQ1128 | Human | 23411 | Details Get a Quote |
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Frequently Asked Questions About keratin filament binding
What is GO:1990254 keratin filament binding?
GO:1990254 is a Gene Ontology molecular function term defined as binding to a keratin filament, an intermediate filament composed of acidic and basic keratins (types I and II), typically expressed in epithelial cells.
What genes are involved in keratin filament binding?
Genes encoding keratins such as KRT5, KRT14, KRT8, and KRT18, as well as binding proteins like TCHP and 14-3-3 isoforms (YWHAB, YWHAG), are involved in keratin filament binding [5,7].
How is keratin filament binding regulated?
It is regulated by phosphorylation; for example, 14-3-3 proteins bind phosphorylated keratin 18, and kinase inhibitors like PKC412 can modulate keratin-myosin binding [2,7].
What diseases are associated with keratin filament binding defects?
Defects are linked to epidermolysis bullosa simplex, liver disease, and certain cancers [2,5,6].
What methods are used to study keratin filament binding?
Common methods include co-sedimentation, immunofluorescence, live-cell imaging, CRISPR knockout/knock-in, and mass spectrometry [5,7].
What is the role of trichoplein in keratin filament binding?
Trichoplein is a novel keratin filament-binding protein that localizes to keratin filaments and may regulate their organization.
How do 14-3-3 proteins interact with keratins?
14-3-3 proteins bind to phosphorylated keratin 18 and modulate keratin filament dynamics and hepatocyte mitotic progression.
Can CRISPR be used to model keratin filament binding diseases?
Yes, CRISPR knockout, point mutation, and knock-in models can replicate disease-associated mutations in keratins or binding partners.
What is the clinical significance of keratin filament binding?
It is critical for epithelial integrity; disruption leads to skin blistering and liver injury, making it a therapeutic target [2,6].
How can EDITGENE help with keratin filament binding research?
EDITGENE provides CRISPR knockout, point mutation, knock-in, overexpression, library screening, and bioinformatics services tailored to keratin filament binding studies.
Conclusion
Keratin filament binding (GO:1990254) is a vital molecular function that maintains epithelial cell integrity and regulates cytoskeletal dynamics. Its dysregulation contributes to diseases such as epidermolysis bullosa simplex and liver injury, highlighting its clinical relevance [2,6]. Advances in CRISPR technology and biochemical assays continue to unravel the mechanisms and therapeutic potential of keratin filament binding [5,7].
References
- 1. Hintner H et al.. 1989. Vitronectin shows complement-independent binding to isolated keratin filament aggregates.. J Invest Dermatol 93(5):656-61 PMID: 2477464
- 2. Kwan R et al.. 2015. PKC412 normalizes mutation-related keratin filament disruption and hepatic injury in mice by promoting keratin-myosin binding.. Hepatology 62(6):1858-69 PMID: 26126491
- 3. Hintner H. 1987. [Anti-keratin filament autoantibodies].. Hautarzt 38(3):131-7 PMID: 2438253
- 4. Eldirany SA et al.. 2021. Recent insight into intermediate filament structure.. Curr Opin Cell Biol 68:132-143 PMID: 33190098
- 5. Nishizawa M et al.. 2005. Identification of trichoplein, a novel keratin filament-binding protein.. J Cell Sci 118(Pt 5):1081-90 PMID: 15731013
- 6. Bergson S et al.. 2025. HMCN1 variants aggravate epidermolysis bullosa simplex phenotype.. J Exp Med 222(5) PMID: 39976600
- 7. Ku NO et al.. 2002. Keratin binding to 14-3-3 proteins modulates keratin filaments and hepatocyte mitotic progression.. Proc Natl Acad Sci U S A 99(7):4373-8 PMID: 11917136
- 8. Miettinen M et al.. 1984. Synovial sarcoma--a misnomer.. Am J Pathol 117(1):18-25 PMID: 6207733
