GO:0140288 GBAF complex: Components, Assembly and Research Methods, Genes, Functions and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0140288 (GBAF complex) is a SWI/SNF subcomplex defined by mutually exclusive incorporation of GLTSCR1 or GLTSCR1L together with BRD9 and the BAF subunits BAF155, BAF60, SS18, BAF53a, and BRG1/BRM.
• GBAF is a non-canonical BAF variant that regulates naive pluripotency in mouse embryonic stem cells and is conserved in early porcine development.
• GBAF is activated in synovial sarcoma, where it reprograms transcription at polycomb targets while cBAF enhancers are lost.
• BRD9 degraders unleash GBAF chromatin remodeling activity in synovial sarcoma, linking GBAF to therapeutic vulnerability.
• SUMOylation targeting stabilizes cBAF and disrupts the SS18::SSX transcriptome, indirectly affecting GBAF balance.
• GBAF interacts with FET fusion oncoproteins, which enrich specific SWI/SNF subtypes and interaction partners.
Description
The GBAF complex (GO:0140288) is a SWI/SNF subcomplex that incorporates two mutually exclusive paralogs, GLTSCR1 or GLTSCR1L, together with BRD9 and the BAF subunits BAF155, BAF60, SS18, BAF53a, and BRG1/BRM. This composition distinguishes GBAF from canonical BAF (cBAF) and positions it as a specialized chromatin remodeler with roles in development and disease. Understanding GBAF is important because its subunit exchange and paralog switching can rewire enhancer landscapes and transcriptional programs in cancer and stem cell states. Recent studies have shown that GBAF is present in early porcine development and that its intra-complex interactions and transcriptional dynamics can be tracked during embryogenesis. In synovial sarcoma, GBAF activation at polycomb targets and loss of cBAF enhancers drive a distinct transcriptional reprogramming that can be targeted by BRD9 degraders. FET fusion oncoproteins further enrich SWI/SNF complex subtypes and interaction partners, implicating GBAF in fusion-driven oncogenesis. Targeting SUMOylation stabilizes cBAF and disrupts the SS18::SSX transcriptome, highlighting the dynamic interplay between GBAF and cBAF in sarcoma. This article synthesizes the authoritative QuickGO definition and verified PubMed literature to provide a research-grade overview of GBAF complex components, assembly, functions, and experimental methods.
GBAF complex At A Glance
| GO ID | GO:0140288 |
|---|---|
| GO term | GBAF complex |
| Ontology | cellular_component |
| Synonym | none |
| Major function | SWI/SNF subcomplex that incorporates GLTSCR1 or GLTSCR1L, BRD9, and BAF subunits BAF155, BAF60, SS18, BAF53a, and BRG1/BRM |
| Paralog switch | Mutually exclusive incorporation of GLTSCR1 or GLTSCR1L |
| Key bromodomain subunit | BRD9 |
| Core BAF subunits | BAF155, BAF60, SS18, BAF53a, BRG1/BRM |
| Developmental role | Regulates naive pluripotency in mouse embryonic stem cells and is present during early porcine development |
| Disease link | Synovial sarcoma and FET fusion oncoprotein-driven cancers |
What Is GO:0140288?
According to QuickGO, GO:0140288 (GBAF complex) is a SWI/SNF subcomplex that incorporates two mutually exclusive paralogs, GLTSCR1 (glioma tumor suppressor candidate region gene 1) or GLTSCR1L (GLTSCR1-like), BRD9 (bromodomain-containing 9) and the BAF subunits BAF155, BAF60, SS18, BAF53a, and BRG1/BRM. In other words, GBAF is a variant SWI/SNF chromatin remodeling complex defined by the presence of either GLTSCR1 or GLTSCR1L, the bromodomain protein BRD9, and a specific set of BAF core subunits, distinguishing it from canonical BAF complexes.
Why Is GBAF complex Important in Cell Biology?
The GBAF complex is important because it represents a non-canonical SWI/SNF subcomplex whose subunit composition and paralog switching can dictate chromatin accessibility and transcriptional programs in stem cells and cancer. Its presence and dynamics during early development suggest roles in lineage specification and pluripotency maintenance. In synovial sarcoma, GBAF activation at polycomb targets and loss of cBAF enhancers contribute to oncogenic reprogramming, and BRD9 degraders can unleash GBAF chromatin remodeling activity, offering a therapeutic angle. FET fusion oncoproteins enrich SWI/SNF subtypes, further implicating GBAF in fusion-driven malignancies. Targeting SUMOylation stabilizes cBAF and disrupts the SS18::SSX transcriptome, underscoring the regulatory crosstalk between GBAF and cBAF.
• GBAF is a distinct SWI/SNF subcomplex defined by GLTSCR1/GLTSCR1L and BRD9, making it a key node for chromatin remodeling research.
• It regulates naive pluripotency in mouse embryonic stem cells, linking it to stem cell biology.
• GBAF is present and transcriptionally dynamic during early porcine development, suggesting conserved developmental roles.
• In synovial sarcoma, GBAF activation at polycomb targets and loss of cBAF enhancers drive transcriptional reprogramming.
• BRD9 degraders unleash GBAF chromatin remodeling activity in synovial sarcoma, highlighting therapeutic potential.
• FET fusion oncoproteins enrich SWI/SNF complex subtypes and interaction partners, implicating GBAF in fusion-driven cancers.
• SUMOylation targeting stabilizes cBAF and disrupts the SS18::SSX transcriptome, revealing crosstalk between GBAF and cBAF.
• GBAF subunit composition can be studied using knockout, knock-in, and tagged knock-in models to dissect assembly and function.
• Understanding GBAF may inform strategies for cancers driven by SWI/SNF perturbations.
• GBAF research benefits from CRISPR screening and bioinformatics to identify context-specific dependencies.
Core Biology of GBAF complex
Assembly and Subunit Exchange
In simple terms: GBAF is built by swapping in specific proteins instead of the usual ones.
The GBAF complex assembles as a SWI/SNF subcomplex that incorporates two mutually exclusive paralogs, GLTSCR1 or GLTSCR1L, together with BRD9 and the BAF subunits BAF155, BAF60, SS18, BAF53a, and BRG1/BRM. This composition distinguishes it from canonical BAF complexes and suggests a modular assembly process where paralog choice may dictate targeting and function. Intra-complex interactions and transcriptional dynamics of GBAF have been tracked during early porcine development, indicating that assembly is developmentally regulated.
Chromatin Remodeling Activity
In simple terms: GBAF slides or repositions nucleosomes to change how genes are read.
As a SWI/SNF subcomplex, GBAF uses the ATPase subunits BRG1/BRM to remodel chromatin. BRD9 degraders unleash GBAF chromatin remodeling activity in synovial sarcoma, demonstrating that GBAF can be activated by perturbing its bromodomain subunit. This remodeling activity is linked to transcriptional reprogramming at polycomb targets and loss of cBAF enhancers in synovial sarcoma.
Developmental and Pluripotency Roles
In simple terms: GBAF helps keep stem cells in a naive state and supports early development.
A non-canonical BRD9-containing BAF chromatin remodeling complex regulates naive pluripotency in mouse embryonic stem cells. GBAF presence, intra-complex interactions, and transcriptional dynamics have been identified during early porcine development, suggesting conserved roles in embryogenesis.
Crosstalk with cBAF and SUMOylation
In simple terms: GBAF and cBAF can shift balance, and SUMOylation affects this balance.
Targeting SUMOylation leads to cBAF complex stabilization and disruption of the SS18::SSX transcriptome in synovial sarcoma, indicating regulatory crosstalk between cBAF and GBAF. In synovial sarcoma, GBAF activation at polycomb targets and loss of cBAF enhancers further illustrate the dynamic interplay between these subcomplexes.
Interaction with Fusion Oncoproteins
In simple terms: GBAF can be recruited by cancer-causing fusion proteins.
FET fusion oncoproteins enrich SWI/SNF complex subtypes and interaction partners, implicating GBAF in fusion-driven oncogenesis. This suggests that GBAF may be a key effector of fusion oncoprotein transcriptional programs.
Key Genes Involved in GO:0140288 GBAF complex
The following genes and proteins are core components or key interactors of the GBAF complex, based on the QuickGO definition and verified literature.
| Gene | Major Role | Research Relevance |
|---|---|---|
| GLTSCR1 | Mutually exclusive paralog incorporated into GBAF | Defines GBAF identity; potential tumor suppressor context |
| GLTSCR1L | Mutually exclusive paralog incorporated into GBAF | Alternative GBAF variant; developmental roles |
| BRD9 | Bromodomain-containing subunit of GBAF | Target for degraders; regulates naive pluripotency |
| BAF155 | Core BAF subunit in GBAF | Scaffold for complex assembly |
| BAF60 | Core BAF subunit in GBAF | Modulates chromatin remodeling |
| SS18 | Core BAF subunit in GBAF | Fusion partner in synovial sarcoma |
| BAF53a | Core BAF subunit in GBAF | Actin-related protein in SWI/SNF |
| BRG1 | ATPase subunit of GBAF | Catalytic engine of chromatin remodeling |
| BRM | ATPase subunit of GBAF | Alternative ATPase in GBAF |
| SS18::SSX | Fusion oncoprotein affecting SWI/SNF | Drives synovial sarcoma; cBAF/GBAF balance |
| FET fusion proteins | Enrich SWI/SNF subtypes | Implicated in fusion-driven cancers |
| SUMOylation machinery | Regulates cBAF stability | Therapeutic target in synovial sarcoma |
| Polycomb targets | GBAF-activated genes | Transcriptional reprogramming in sarcoma |
| cBAF enhancers | Lost in synovial sarcoma | Contrasts with GBAF activation |
| BAF complex subunits | Core SWI/SNF components | Context for GBAF assembly |
| BRD9-containing BAF | Non-canonical complex | Regulates naive pluripotency |
| GBAF complex | SWI/SNF subcomplex | Central entity of GO:0140288 |
How Is GBAF complex Regulated?
GBAF complex regulation involves subunit exchange and post-translational modifications. Targeting SUMOylation stabilizes cBAF and disrupts the SS18::SSX transcriptome, indicating that SUMOylation influences the balance between cBAF and GBAF. BRD9 degraders can unleash GBAF chromatin remodeling activity, suggesting that BRD9 levels or activity regulate GBAF function. FET fusion oncoproteins enrich SWI/SNF complex subtypes and interaction partners, providing another layer of regulation in cancer contexts. Developmental cues also regulate GBAF assembly and transcriptional dynamics, as shown during early porcine development.
GBAF complex and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| BRD9 | Synovial sarcoma; naive pluripotency | BRD9 degrader treatment in sarcoma cell lines |
| SS18::SSX | Synovial sarcoma | Knockdown or knockout of fusion in sarcoma cells |
| GLTSCR1 | Glioma tumor suppressor candidate | Knockout in glioma models |
| GLTSCR1L | Developmental roles | Knockout in embryonic stem cells |
| SUMOylation enzymes | Synovial sarcoma | SUMOylation inhibitor treatment |
Synovial Sarcoma
Synovial sarcoma reprograms transcription by GBAF activation of polycomb targets and loss of cBAF enhancers. Targeting SUMOylation promotes cBAF complex stabilization and disruption of the SS18::SSX transcriptome, linking GBAF/cBAF balance to sarcoma biology. BRD9 degraders unleash GBAF chromatin remodeling activity in synovial sarcoma, highlighting a therapeutic vulnerability.
Fusion Oncoprotein-Driven Cancers
FET fusion oncoproteins enrich SWI/SNF complex subtypes and interaction partners, implicating GBAF in fusion-driven oncogenesis beyond synovial sarcoma. This suggests that GBAF may be a general effector of fusion oncoprotein transcriptional programs.
Developmental and Stem Cell Biology
A non-canonical BRD9-containing BAF chromatin remodeling complex regulates naive pluripotency in mouse embryonic stem cells. GBAF presence and dynamics during early porcine development suggest roles in embryogenesis and lineage specification.
From GBAF complex-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| What is the role of GLTSCR1 vs GLTSCR1L in GBAF assembly? | Knockout of each paralog in cell lines |
| How does BRD9 degradation affect GBAF activity? | BRD9 degrader treatment in synovial sarcoma cells |
| Does GBAF regulate naive pluripotency? | Knockout of BRD9 or GBAF subunits in mouse embryonic stem cells |
| How does GBAF dynamics change during development? | Tagged knock-in of GBAF subunits in porcine embryos |
| What is the crosstalk between SUMOylation and GBAF/cBAF? | SUMOylation inhibitor treatment in sarcoma cells |
| How do FET fusion proteins interact with GBAF? | Overexpression of FET fusion proteins followed by proteomics |
How to Study the GBAF complex Process
| Method | What It Measures | Typical Application |
|---|---|---|
| Affinity purification mass spectrometry | Protein interactions and complex composition | Identifying GBAF subunits and partners |
| RNA-seq | Transcriptional changes | GBAF-dependent gene expression |
| ChIP-seq | Chromatin occupancy | GBAF binding at polycomb targets |
| BRD9 degrader treatment | GBAF activity | Unleashing chromatin remodeling |
| SUMOylation inhibition | cBAF stabilization | Disrupting SS18::SSX transcriptome |
| CRISPR knockout | Gene function | Dissecting paralog roles |
| Tagged knock-in | Protein localization and dynamics | Tracking GBAF during development |
| Proteomics of fusion proteins | Interaction partners | FET fusion oncoprotein studies |
Proteomics and Interaction Studies
Affinity purification coupled to mass spectrometry can identify GBAF subunits and interaction partners, as shown for SWI/SNF subtypes enriched by FET fusion oncoproteins. Intra-complex interactions of GBAF have been studied during early porcine development using such approaches.
Transcriptional Profiling
RNA-seq and chromatin profiling can reveal GBAF-dependent transcriptional programs, such as activation of polycomb targets and loss of cBAF enhancers in synovial sarcoma. Transcriptional dynamics of GBAF during development have also been tracked.
Perturbation with Degraders and Inhibitors
BRD9 degraders can unleash GBAF chromatin remodeling activity, providing a chemical biology tool to study GBAF function. SUMOylation inhibitors stabilize cBAF and disrupt the SS18::SSX transcriptome, enabling studies of cBAF/GBAF balance.
CRISPR Screening and Bioinformatics
CRISPR library screening and bioinformatics can identify context-specific dependencies of GBAF subunits and their paralogs. Such approaches help dissect the functional consequences of GBAF composition in different cell states.
How CRISPR Can Be Used to Study GO:0140288 GBAF complex
Knockout
CRISPR knockout of GBAF subunits such as GLTSCR1, GLTSCR1L, BRD9, or BAF components can reveal their roles in complex assembly and function. Knockout of BRD9 in mouse embryonic stem cells has been used to study naive pluripotency.
Point Mutation
Point mutations can be introduced into GBAF subunits to dissect domain functions, such as bromodomain mutations in BRD9 or ATPase mutations in BRG1/BRM. Such models help separate chromatin remodeling activity from scaffolding functions.
Knock-in
Tagged knock-in of GBAF subunits enables tracking of complex localization and dynamics, as demonstrated during early porcine development. Knock-in of fusion oncoproteins like SS18::SSX can model synovial sarcoma.
Overexpression
Overexpression of FET fusion oncoproteins can enrich SWI/SNF subtypes and interaction partners, facilitating studies of GBAF recruitment. Overexpression of GBAF subunits may also help probe dosage effects.
How EDITGENE Supports GBAF complex Research
Researchers studying GBAF complex-related genes often need to determine whether a candidate gene is causally involved in complex assembly, chromatin remodeling, or disease phenotypes. EDITGENE provides CRISPR-based services to generate precisely engineered cell models for such investigations.
Contact EDITGENE today to design your custom CRISPR model for GBAF complex research.
Frequently Asked Questions About GBAF complex
What is the GBAF complex?
The GBAF complex (GO:0140288) is a SWI/SNF subcomplex that incorporates two mutually exclusive paralogs, GLTSCR1 or GLTSCR1L, BRD9, and the BAF subunits BAF155, BAF60, SS18, BAF53a, and BRG1/BRM.
What genes are involved in the GBAF complex?
Key genes include GLTSCR1, GLTSCR1L, BRD9, BAF155, BAF60, SS18, BAF53a, and BRG1/BRM.
What is the function of GO:0140288?
GO:0140288 describes a SWI/SNF subcomplex involved in chromatin remodeling and transcriptional regulation.
How is GBAF different from cBAF?
GBAF incorporates GLTSCR1 or GLTSCR1L and BRD9, whereas cBAF has a different subunit composition; their balance can shift in disease.
What diseases are linked to GBAF?
GBAF is implicated in synovial sarcoma and FET fusion oncoprotein-driven cancers.
Can BRD9 degraders target GBAF?
Yes, BRD9 degraders unleash GBAF chromatin remodeling activity in synovial sarcoma.
How is GBAF regulated?
SUMOylation targeting stabilizes cBAF and disrupts the SS18::SSX transcriptome, affecting GBAF/cBAF balance.
What model systems are used to study GBAF?
Mouse embryonic stem cells, porcine embryos, and sarcoma cell lines are used, along with CRISPR knockouts and tagged knock-ins.
What methods study GBAF interactions?
Affinity purification mass spectrometry and proteomics identify GBAF subunits and partners.
Why is GBAF important in development?
GBAF regulates naive pluripotency and shows dynamic expression during early development.
Conclusion
The GBAF complex (GO:0140288) is a specialized SWI/SNF subcomplex defined by GLTSCR1/GLTSCR1L, BRD9, and core BAF subunits, with critical roles in chromatin remodeling, pluripotency, and development. Its dysregulation is linked to synovial sarcoma and fusion oncoprotein-driven cancers, where GBAF activation and cBAF loss reprogram transcription. Targeting SUMOylation or BRD9 can modulate GBAF activity, offering therapeutic avenues. Continued research using CRISPR models and bioinformatics will further elucidate GBAF biology and its potential as a drug target.
References
- 1. Innis SM et al.. 2020. GBAF, a small BAF sub-complex with big implications: a systematic review.. Epigenetics Chromatin 13(1):48 PMID: 33143733
- 2. Lindén M et al.. 2025. FET fusion oncoproteins enrich SWI/SNF complex subtypes and interaction partners.. Cell Mol Biol Lett 30(1):107 PMID: 40988026
- 3. Innis S et al.. 2024. Identification of SWI/SNF Subcomplex GBAF Presence, Intra-Complex Interactions, and Transcriptional Dynamics during Early Porcine Development.. Animals (Basel) 14(5) PMID: 38473159
- 4. Floros KV et al.. 2025. Targeting SUMOylation promotes cBAF complex stabilization and disruption of the SS18::SSX transcriptome in synovial sarcoma.. Nat Commun 16(1):9761 PMID: 41193430
- 5. Li J et al.. 2025. Synovial sarcoma reprograms transcription by GBAF activation of polycomb targets and loss of CBAF enhancers.. Nat Commun 17(1):1081 PMID: 41423472
- 6. Floros KV et al.. 2024. Targeting of SUMOylation leads to cBAF complex stabilization and disruption of the SS18::SSX transcriptome in Synovial Sarcoma.. Res Sq PMID: 38883782
- 7. Gatchalian J et al.. 2018. A non-canonical BRD9-containing BAF chromatin remodeling complex regulates naive pluripotency in mouse embryonic stem cells.. Nat Commun 9(1):5139 PMID: 30510198
- 8. Li J et al.. 2026. BRD9 Degraders Unleash GBAF Chromatin Remodeling Activity in Synovial Sarcoma.. Cancer Res PMID: 42361322
