GO:0097655 serpin family protein binding: Mechanism, Genes and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0097655 (serpin family protein binding) is a molecular function describing the selective binding of a protein to a member of the serpin superfamily, a group of structurally conserved serine protease inhibitors.
• Serpins use a unique conformational-change mechanism, the stressed-to-relaxed transition, to trap and inhibit target proteases, and this binding event is central to controlling proteolytic cascades.
• The term covers binding to inhibitory serpins (e.g., SERPINA1, SERPINE1, SERPINB3) as well as non-inhibitory serpins that act as hormone transporters, chaperones, or tumor suppressors.
• Dysregulated serpin-protein interactions contribute to cancer progression, liver fibrosis, and immune-related disorders, making this GO term clinically relevant.
• CRISPR knockout, point-mutation, knock-in, and overexpression models are powerful tools to dissect serpin binding interfaces and downstream signaling.
• Understanding GO:0097655 supports drug discovery targeting serpin-protein interactions in oncology, fibrosis, and inflammation.
Description
GO:0097655, serpin family protein binding, is a molecular function term in the Gene Ontology that describes the binding of a protein to a member of the serpin superfamily. Serpins are a broadly distributed family of protease inhibitors that use a conformational change to inhibit target enzymes, and they are central in controlling many important proteolytic cascades. The majority of serpins inhibit serine proteases, but serpins that inhibit caspases and papain-like cysteine proteases have also been identified. Rarely, serpins perform a non-inhibitory function; for example, several human serpins function as hormone transporters and certain serpins function as molecular chaperones or tumor suppressors. This GO term is therefore essential for annotating interactions that regulate proteolysis, hormone transport, and tumor suppression. Researchers studying serpin biology need precise functional annotation to link genotype to phenotype in diseases such as cancer, fibrosis, and immune disorders. The term also guides experimental design for CRISPR-based models that test the consequences of disrupting serpin-protein binding.
serpin family protein binding At A Glance
| GO ID | GO:0097655 |
|---|---|
| GO term | serpin family protein binding |
| Ontology | molecular_function |
| Synonym | none |
| Major function | Binding to a member of the serpin protein family, which are serine protease inhibitors or classified inhibitor family I4. |
| Mechanism | Serpins use a conformational change (stressed-to-relaxed transition) to inhibit target enzymes, and binding is central to this process. |
| Target proteases | Mostly serine proteases, but also caspases and papain-like cysteine proteases. |
| Non-inhibitory roles | Some serpins function as hormone transporters, molecular chaperones, or tumor suppressors. |
| Disease relevance | Implicated in cancer, liver fibrosis, and immune system disturbances. |
What Is GO:0097655?
In our own words, GO:0097655 describes the molecular function of selectively and non-covalently interacting with a protein that belongs to the serpin family (serine protease inhibitors or classified inhibitor family I4). This binding can occur with inhibitory serpins, which undergo a conformational change to trap target proteases, or with non-inhibitory serpins that act as transporters, chaperones, or tumor suppressors.
Why Is serpin family protein binding Important in Cell Biology?
GO:0097655 is important because serpin-protein binding events control proteolytic cascades that underlie thrombosis, inflammation, cancer, and fibrosis. Accurate annotation of this molecular function enables researchers to interpret high-throughput interaction data and to design targeted experiments that test causality. Because serpins can also act non-inhibitorily as hormone transporters or tumor suppressors, the term captures a wide range of biological outcomes beyond protease inhibition.
• Controls proteolytic cascades involved in blood coagulation, inflammation, and tissue remodeling.
• Regulates cancer cell metastasis through serpin-mRNA stabilization and protein interactions.
• Modulates liver fibrosis and ductular reaction via EP300/YAP1-SERPINE1 signaling.
• Influences lung tumorigenesis through SERPINB3-mediated NPM1 sumoylation.
• Links to immune system disturbances observed in schizophrenia.
• Provides a mechanistic basis for non-inhibitory serpin functions such as hormone transport and chaperone activity.
• Supports drug discovery targeting serpin-protein interfaces in oncology and fibrosis.
• Enables functional annotation of CRISPR screens that perturb serpin genes.
• Helps interpret genetic variants that alter serpin binding affinity.
• Connects protease inhibitor biology to broader systems-level regulation of proteostasis.
Molecular Mechanism of serpin family protein binding
Conformational Change and Protease Trapping
In simple terms: Serpins change shape to trap their target protease, like a mousetrap snapping shut.
Serpins are metastable proteins that undergo a stressed-to-relaxed conformational transition upon binding to a target protease. This change translocates the protease to the opposite pole of the serpin and distorts its active site, effectively trapping the enzyme. The catalytic serine of the protease contributes to the binding energy of the serpin-proteinase complex, and covalent interaction is part of this mechanism.
Binding to Inhibitory vs Non-inhibitory Serpins
In simple terms: Some serpins block enzymes, while others carry hormones or act as chaperones.
The majority of serpins inhibit serine proteases, but serpins that inhibit caspases and papain-like cysteine proteases have also been identified. Rarely, serpins perform non-inhibitory functions; for example, several human serpins function as hormone transporters and certain serpins function as molecular chaperones or tumor suppressors. GO:0097655 encompasses binding to both inhibitory and non-inhibitory serpins.
Cofactors and Heparin Binding
In simple terms: Some serpins need helper molecules like heparin to work efficiently.
Ovalbumin-related protein X is a heparin-binding ov-serpin exhibiting antimicrobial activities, illustrating that cofactor binding such as heparin can modulate serpin function. Such cofactors can influence the conformation and target specificity of serpins, thereby affecting GO:0097655-mediated interactions.
Regulation by Proteolytic Cleavage and Sumoylation
In simple terms: Serpin activity can be turned on or off by cutting or tagging with small proteins.
SERPINB3 enhances NPM1 sumoylation via inhibiting SENP3's activity and promotes lung tumorigenesis, showing that serpin-protein binding can regulate post-translational modifications. Proteolytic cleavage of serpins can also convert them from inhibitory to non-inhibitory conformations, altering their binding partners.
Interaction with Signaling Scaffolds
In simple terms: Serpins can bind to signaling proteins and change how cells respond to stress.
EP300/YAP1-SERPINE1 signaling regulates ductular reaction and liver fibrosis in biliary atresia, demonstrating that serpin binding can interface with transcriptional coactivators and Hippo pathway effectors. Similarly, LncRNA SNHG1 facilitates colorectal cancer cell metastasis by recruiting HNRNPD protein to stabilize SERPINA3 mRNA, linking serpin mRNA stability to RNA-binding proteins.
Key Genes Involved in GO:0097655 serpin family protein binding
The following genes encode serpins or proteins that bind serpins, and they are frequently studied in the context of GO:0097655.
| Gene | Major Role | Research Relevance |
|---|---|---|
| SERPINA1 | Inhibits neutrophil elastase; prototype inhibitory serpin | Model for serpin conformational disease and protease inhibition |
| SERPINE1 | Inhibits plasminogen activators; regulates fibrosis | Linked to liver fibrosis and ductular reaction via EP300/YAP1 signaling |
| SERPINB3 | Inhibits cysteine proteases; regulates sumoylation | Promotes lung tumorigenesis by inhibiting SENP3 |
| SERPINA3 | Inhibits cathepsin G; acute-phase protein | mRNA stabilized by HNRNPD in colorectal cancer metastasis |
| SERPINB1 | Inhibits neutrophil elastase; involved in inflammation | Studied in immune regulation and cancer |
| SERPINB5 | Tumor suppressor; inhibits plasminogen activators | Relevant to cancer invasion and metastasis |
| SERPINC1 | Antithrombin; inhibits thrombin and factor Xa | Central to coagulation cascade regulation |
| SERPIND1 | Heparin cofactor II; inhibits thrombin | Model for heparin-dependent serpin activity |
| SERPINF1 | Neurotrophic serpin; inhibits angiogenesis | Studied in neurodegeneration and cancer |
| SERPING1 | Inhibits C1 esterase; complement regulation | Linked to hereditary angioedema and immune disorders |
| SERPINI1 | Neuroserpin; inhibits tissue plasminogen activator | Implicated in neurodegenerative diseases |
| HNRNPD | RNA-binding protein that stabilizes SERPINA3 mRNA | Modulates serpin expression in colorectal cancer |
| SENP3 | De-sumoylating enzyme inhibited by SERPINB3 | Regulates NPM1 sumoylation in lung cancer |
| EP300 | Transcriptional coactivator regulating SERPINE1 | Controls ductular reaction in biliary atresia |
| YAP1 | Hippo pathway effector regulating SERPINE1 | Drives liver fibrosis and ductular reaction |
| NPM1 | Nucleolar protein sumoylated upon SERPINB3 binding | Promotes lung tumorigenesis |
| METTL3 | RNA methyltransferase; interacts with eIF3H | Screened in gastric cancer for oxaliplatin sensitivity |
| eIF3H | Translation initiation factor; binds METTL3 | Target of METTL3 dephosphorylation in gastric cancer |
How Is serpin family protein binding Regulated?
Serpin family protein binding is regulated at multiple levels. Conformational changes in serpins control their transition from stressed to relaxed states, which is essential for protease trapping. Cofactors such as heparin can enhance or alter binding specificity, as seen with heparin-binding ov-serpins. Post-translational modifications, including sumoylation, can be modulated by serpin binding; for example, SERPINB3 inhibits SENP3 to enhance NPM1 sumoylation. Transcriptional regulation of serpin genes by EP300/YAP1 signaling further influences the availability of serpins for binding. Additionally, RNA-binding proteins like HNRNPD stabilize SERPINA3 mRNA, affecting protein levels and subsequent binding events.
serpin family protein binding and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| SERPINA3 | Colorectal cancer metastasis | Knockout of HNRNPD in CRC cell lines to assess SERPINA3 mRNA stability |
| SERPINB3 | Lung tumorigenesis | Point mutation of SENP3 binding site to block SERPINB3 inhibition |
| SERPINE1 | Liver fibrosis in biliary atresia | Knock-in of EP300/YAP1 response elements to monitor SERPINE1 expression |
| SERPINC1 | Thrombosis | Overexpression of mutant antithrombin to test heparin binding |
| SERPING1 | Hereditary angioedema | CRISPR knockout of SERPING1 in immune cells to study complement regulation |
Cancer Progression and Metastasis
Serpin-protein interactions are deeply implicated in cancer. LncRNA SNHG1 facilitates colorectal cancer cell metastasis by recruiting HNRNPD protein to stabilize SERPINA3 mRNA. SERPINB3 enhances NPM1 sumoylation via inhibiting SENP3's activity and promotes lung tumorigenesis. These findings highlight GO:0097655 as a potential therapeutic target in oncology.
Liver Fibrosis and Biliary Atresia
EP300/YAP1-SERPINE1 signaling regulates ductular reaction and liver fibrosis in biliary atresia. This demonstrates that serpin binding and downstream signaling contribute to fibrotic liver disease, offering experimental models to test interventions.
Immune System Disturbances
Immune system disturbances in schizophrenia have been linked to serpin-related pathways. Although the exact mechanisms remain under investigation, this association suggests that GO:0097655 may influence neuroimmune interactions.
Coagulation and Thrombosis
Serpins such as antithrombin (SERPINC1) and heparin cofactor II (SERPIND1) regulate coagulation by binding to thrombin and factor Xa. Dysregulation of these interactions can lead to thrombotic disorders, underscoring the clinical importance of serpin family protein binding.
From serpin family protein binding-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does loss of SERPINA3 affect cancer cell migration? | CRISPR knockout of SERPINA3 in colorectal cancer cell lines |
| Does a point mutation in SERPINB3 abolish SENP3 inhibition? | Point mutation knock-in of SERPINB3 in lung cancer cells |
| Can tagged SERPINE1 reveal its binding partners? | Knock-in of FLAG-tagged SERPINE1 in liver cells |
| Does overexpression of SERPINC1 alter coagulation? | Overexpression of wild-type or mutant SERPINC1 in hepatocytes |
| Which proteins bind to serpin family members? | CRISPR library screening with serpin baits |
| Does METTL3 dephosphorylation affect serpin interactions? | Point mutation of METTL3 phosphorylation sites in gastric cancer cells |
How to Study the serpin family protein binding Process
| Method | What It Measures | Typical Application |
|---|---|---|
| Co-immunoprecipitation | Physical interaction between serpin and binding partner | Validation of GO:0097655 interactions |
| Mass spectrometry | Identification of serpin-binding proteins | Discovery of novel interactors |
| CRISPR knockout | Loss-of-function effects on serpin binding | Testing causality in cancer cell lines |
| Point mutation knock-in | Effect of specific residues on binding affinity | Mapping binding interfaces |
| RNA-seq | Transcriptional changes upon serpin perturbation | Pathway analysis in disease models |
| FRET | Conformational changes during binding | Real-time monitoring of serpin-protease interactions |
| Actinomycin D chase | mRNA stability of serpin transcripts | Assessing HNRNPD-mediated stabilization |
| CRISPR library screening | Genome-wide modifiers of serpin binding | Identifying synthetic lethal partners |
CRISPR Screening for Serpin Interactors
Genome-wide CRISPR screens can identify genes that modulate serpin-protein binding. For example, a BE screen revealed METTL3 S2 dephosphorylation sensitizes gastric cancer cells to oxaliplatin by interfering with METTL3-eIF3H interaction. Similar approaches can be adapted to serpin-focused screens.
Proteomics and Co-Immunoprecipitation
Affinity purification coupled with mass spectrometry can identify proteins that bind to serpins, directly annotating GO:0097655. Co-immunoprecipitation of tagged serpins followed by western blotting validates specific interactions.
Transcriptomics and RNA Stability Assays
RNA-seq and mRNA stability assays can measure how serpin-binding proteins affect serpin transcript levels. For instance, HNRNPD stabilizes SERPINA3 mRNA, which can be monitored by actinomycin D chase experiments.
Imaging and Conformational Assays
Fluorescence resonance energy transfer (FRET) and circular dichroism can detect the conformational changes that occur when serpins bind proteases. Live-cell imaging of tagged serpins can reveal their subcellular localization and dynamics.
How CRISPR Can Be Used to Study GO:0097655 serpin family protein binding
Knockout
CRISPR knockout of serpin genes or their binding partners can reveal loss-of-function phenotypes. For example, knocking out SERPINA3 in colorectal cancer cells can test its role in metastasis. Knockout of SENP3 would mimic SERPINB3 inhibition and enhance NPM1 sumoylation.
Point Mutation
Point mutations can be introduced to disrupt specific binding interfaces. Mutating the catalytic serine of a protease or the reactive center loop of a serpin can abolish covalent complex formation, as shown for serpin-proteinase interactions. Such models help map the energetic contributions of individual residues.
Knock-in
Knock-in of tagged serpins (e.g., FLAG-SERPINE1) enables affinity purification and imaging of binding events in native chromatin context. Knock-in of disease-associated mutations can model altered serpin binding in liver fibrosis or thrombosis.
Overexpression
Overexpression of wild-type or mutant serpins can drive gain-of-function phenotypes. For instance, overexpressing SERPINB3 in lung cells promotes tumorigenesis via SENP3 inhibition. Overexpression of SERPINC1 mutants can test anticoagulant activity.
How EDITGENE Supports serpin family protein binding Research
Researchers studying serpin family protein binding-related genes often need to determine whether a candidate gene is causally involved in a specific biological process or disease. EDITGENE provides a comprehensive suite of CRISPR services to accelerate this discovery, from knockout to knock-in and library screening.
Contact EDITGENE today to design your custom CRISPR model for serpin family protein binding research.
Frequently Asked Questions About serpin family protein binding
What is GO:0097655?
GO:0097655 is the Gene Ontology molecular function term for serpin family protein binding, which describes binding to a member of the serpin superfamily of protease inhibitors.
What genes are involved in serpin family protein binding?
Key genes include SERPINA1, SERPINE1, SERPINB3, SERPINA3, SERPINC1, and SERPIND1, as well as binding partners like HNRNPD, SENP3, EP300, and YAP1.
How do serpins inhibit proteases?
Serpins undergo a conformational change from a stressed to a relaxed state, trapping the target protease and distorting its active site.
What diseases are linked to serpin family protein binding?
Diseases include cancer metastasis, liver fibrosis, thrombosis, and immune system disturbances such as schizophrenia.
Can CRISPR be used to study serpin family protein binding?
Yes, CRISPR knockout, point mutation, knock-in, and overexpression models are widely used to dissect serpin interactions and their downstream effects.
What is the role of SERPINB3 in cancer?
SERPINB3 enhances NPM1 sumoylation by inhibiting SENP3, promoting lung tumorigenesis.
How is SERPINA3 mRNA stabilized?
LncRNA SNHG1 recruits HNRNPD protein to stabilize SERPINA3 mRNA, facilitating colorectal cancer metastasis.
What is the connection between SERPINE1 and liver fibrosis?
EP300/YAP1-SERPINE1 signaling regulates ductular reaction and liver fibrosis in biliary atresia.
Are there non-inhibitory serpins?
Yes, some serpins function as hormone transporters, molecular chaperones, or tumor suppressors.
What methods are used to study serpin binding?
Common methods include co-immunoprecipitation, mass spectrometry, FRET, CRISPR screens, and RNA-seq.
Conclusion
GO:0097655, serpin family protein binding, is a critical molecular function that governs protease inhibition, hormone transport, and tumor suppression. Its dysregulation is linked to cancer, fibrosis, and immune disorders, making it a compelling target for therapeutic intervention. By leveraging CRISPR-based models and advanced screening technologies, researchers can uncover the precise mechanisms of serpin-protein interactions and translate these findings into clinical applications.
References
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- 3. Xu X et al.. 2025. BE screen reveals METTL3 S2 dephosphorylation sensitizes gastric cancer cells to oxaliplatin by interfering METTL3-eIF3H interaction.. Sci Adv 11(50):eady7259 PMID: 41385641
- 4. Zhu Z et al.. 2026. EP300/YAP1-SERPINE1 Signaling Regulates Ductular Reaction and Liver Fibrosis in Biliary Atresia.. Cell Mol Gastroenterol Hepatol 20(1):101640 PMID: 40992734
- 5. Yang H et al.. 2024. LncRNA SNHG1 facilitates colorectal cancer cells metastasis by recruiting HNRNPD protein to stabilize SERPINA3 mRNA.. Cancer Lett 604:217217 PMID: 39233042
- 6. Meng X et al.. 2025. SERPINB3 enhances NPM1 sumoylation via inhibiting SENP3's activity and promotes lung tumorigenesis.. Cell Death Dis 17(1):133 PMID: 41444337
- 7. Réhault-Godbert S et al.. 2013. Ovalbumin-related protein X is a heparin-binding ov-serpin exhibiting antimicrobial activities.. J Biol Chem 288(24):17285-95 PMID: 23615912
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