GO:0048188 Set1C/COMPASS complex: Components, Assembly and Research Methods, Genes, Functions and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0048188 (Set1C/COMPASS complex) is a conserved histone H3 lysine 4 (H3K4) methyltransferase complex that exists in yeast and mammals.
• In Saccharomyces cerevisiae, the complex contains Shg1p, Sdc1p, Swd1p, Swd2p, Swd3p, Spp1p, Bre2p and the catalytic subunit Set1p.
• In mammals, the complex contains SETD1A or SETD1B, WDR5, WDR82, RBBP5, ASH2L/ASH2, CXXC1/CFP1, HCFC1 and DPY30.
• Set1C/COMPASS is dimeric and cooperates with the Jhd2 demethylase to establish symmetrical H3K4 trimethylation.
• The complex controls gene expression, heterochromatin assembly and genome stability through both H3K4 methylation-dependent and independent mechanisms [1,6].
• Set1C/COMPASS is a melanoma-enriched epigenetic vulnerability, making it a candidate therapeutic target [2,3].
Description
The Set1C/COMPASS complex (GO:0048188) is a conserved multi-subunit histone methyltransferase that catalyzes methylation of histone H3, primarily at lysine 4 (H3K4). It was originally identified in Saccharomyces cerevisiae as a Set1-containing complex and later found in mammals with homologous subunits. The complex is a central regulator of chromatin structure and transcription, and its catalytic activity is linked to gene activation, heterochromatin boundaries and genome stability [1,6]. Because H3K4 methylation is a hallmark of active promoters and enhancers, researchers study Set1C/COMPASS to understand how epigenetic marks are written, read and erased. The complex also has H3K4 methylation-independent functions, including coordination with histone deacetylases to repress transcripts and assemble heterochromatin. In recent years, systematic analyses have identified Set1C/COMPASS as a melanoma-enriched epigenetic dependency, highlighting its potential as a cancer therapeutic target [2,3]. This article summarizes the composition, assembly, molecular mechanism and disease relevance of GO:0048188, and outlines CRISPR-based research methods for studying it.
Set1C/COMPASS complex At A Glance
| GO ID | GO:0048188 |
|---|---|
| GO term | Set1C/COMPASS complex |
| Ontology | cellular_component |
| Synonym | COMPASS complex, Set1C, Set1/COMPASS complex |
| Major function | Catalyzes methylation of histone H3, predominantly at lysine 4 (H3K4) |
| Yeast subunits | Shg1p, Sdc1p, Swd1p, Swd2p, Swd3p, Spp1p, Bre2p, Set1p |
| Mammalian subunits | SETD1A or SETD1B, WDR5, WDR82, RBBP5, ASH2L/ASH2, CXXC1/CFP1, HCFC1, DPY30 |
| Assembly | Cotranslational assembly of the yeast SET1C complex has been reported |
| Stoichiometry | The Set1 complex is dimeric |
What Is GO:0048188?
GO:0048188 (Set1C/COMPASS complex) is a cellular component defined as a conserved protein complex that catalyzes methylation of histone H3. In Saccharomyces, the complex contains Shg1p, Sdc1p, Swd1p, Swd2p, Swd3p, Spp1p, Bre2p, and the trithorax-related Set1p; in mammals it contains the catalytic subunit (SETD1A or SETD1B), WDR5, WDR82, RBBP5, ASH2L/ASH2, CXXC1/CFP1, HCFC1 and DPY30. Synonyms include COMPASS complex, Set1C and Set1/COMPASS complex.
Why Is Set1C/COMPASS complex Important in Cell Biology?
Set1C/COMPASS is important because it writes H3K4 methylation, a chromatin mark associated with active transcription, and because it also controls heterochromatin assembly and transcriptome repression independently of H3K4 methylation [1,6]. Its conserved subunit composition and enzymatic activity make it a model system for studying epigenetic regulation, and its dysfunction is linked to cancer and other diseases [2,3]. Understanding Set1C/COMPASS is therefore essential for researchers in chromatin biology, gene regulation and therapeutic development.
• Set1C/COMPASS catalyzes H3K4 methylation, a key epigenetic mark for gene activation.
• It is conserved from yeast to humans, enabling cross-species mechanistic studies.
• The complex is dimeric and works with Jhd2 demethylase to achieve symmetrical H3K4 trimethylation.
• It has H3K4 methylation-independent roles in heterochromatin assembly and transcriptome repression.
• Set1C/COMPASS is a melanoma-enriched epigenetic vulnerability [2,3].
• It is involved in metabolic acid stress resistance in yeast, with potential cancer relevance.
• Dysregulation of H3K4 methylation is associated with developmental disorders and cancers [1,2].
• The complex is a target for CRISPR-based functional genomics and drug discovery [2,3].
• Studying its assembly informs general principles of multi-subunit complex biogenesis.
• Its subunits are potential biomarkers and therapeutic targets in oncology [2,3].
Set1C/COMPASS complex: Biological Process, Structure and Molecular Mechanism
H3K4 Methylation and Transcriptional Regulation
In simple terms: The complex adds methyl marks to histone H3, which helps turn genes on.
Set1C/COMPASS catalyzes methylation of histone H3, predominantly at lysine 4 (H3K4), leading to mono-, di- and trimethylation. These marks are associated with active transcription and are recognized by effector proteins that promote gene expression. The complex also controls genome expression through both H3K4 methylation-dependent and independent mechanisms.
Heterochromatin Assembly and Transcriptome Repression
In simple terms: The complex can also help silence certain regions of the genome.
Set1 coordinates with a class II histone deacetylase to assemble heterochromatin and repress specific transcripts, demonstrating an H3K4 methylation-independent function. This dual role allows Set1C/COMPASS to fine-tune gene expression programs beyond simple activation.
Dimeric Architecture and Symmetrical H3K4 Trimethylation
In simple terms: The complex works as a pair to place methyl marks symmetrically.
The Set1 complex is dimeric and acts together with the Jhd2 demethylase to convey symmetrical H3K4 trimethylation on histone H3. This symmetry is important for stable epigenetic inheritance and proper chromatin function.
Cotranslational Assembly of the Complex
In simple terms: The complex is put together while its parts are being made.
In yeast, the SET1C histone methyltransferase complex assembles cotranslationally, meaning subunits associate during protein synthesis. This mechanism ensures efficient and regulated formation of the functional complex.
Role in Metabolic Stress Resistance
In simple terms: The complex helps cells survive acidic stress, which may relate to cancer.
Systematic identification of genes involved in metabolic acid stress resistance in yeast identified Set1C/COMPASS components, and these genes have potential as cancer targets. This links the complex to stress adaptation pathways relevant to tumor biology.
Key Genes Involved in GO:0048188 Set1C/COMPASS complex
The following genes and proteins are core components or regulators of the Set1C/COMPASS complex (GO:0048188) and are frequently studied in functional genomics research.
| Gene | Major Role | Research Relevance |
|---|---|---|
| SETD1A | Catalytic subunit of mammalian Set1C/COMPASS; methylates H3K4 | Target for cancer and neurodevelopmental studies |
| SETD1B | Catalytic subunit paralog of SETD1A | Implicated in gene regulation and disease |
| WDR5 | Scaffold subunit; interacts with H3K4 methyltransferases | Common target for small-molecule inhibitors |
| WDR82 | Mammalian-specific subunit; links complex to transcription | Studied in chromatin and RNA Pol II regulation |
| RBBP5 | Core subunit required for complex integrity and activity | Frequently mutated in cancers |
| ASH2L | Core subunit; stimulates methyltransferase activity | Epigenetic regulator in development and cancer |
| CXXC1 | CpG-binding subunit; targets complex to promoters | Involved in gene activation and leukemia |
| HCFC1 | Mammalian subunit; connects to cell cycle regulation | Linked to intellectual disability and cancer |
| DPY30 | Small subunit; modulates complex assembly and activity | Emerging target in epigenetic therapy |
| Set1p | Yeast catalytic subunit; H3K4 methyltransferase | Model for studying COMPASS function |
| Shg1p | Yeast subunit; regulates complex stability | Studied in yeast genetics |
| Sdc1p | Yeast subunit; required for H3K4 methylation | Used in mechanistic studies |
| Swd1p | Yeast subunit; interacts with Set1p | Component of the core complex |
| Swd2p | Yeast subunit; links to CPF and transcription | Studied in 3' end processing |
| Swd3p | Yeast subunit; WD40 repeat protein | Structural role in complex |
| Spp1p | Yeast subunit; PHD finger protein | Binds H3K4me3 and regulates complex |
| Bre2p | Yeast subunit; required for H3K4 trimethylation | Functional studies in yeast |
| Jhd2 | H3K4 demethylase; works with Set1C for symmetrical methylation | Regulates H3K4me3 dynamics |
How Is Set1C/COMPASS complex Regulated?
Set1C/COMPASS activity is regulated at multiple levels. The complex assembles cotranslationally in yeast, ensuring proper subunit stoichiometry. Its catalytic output is balanced by the Jhd2 demethylase, which removes H3K4 methylation and helps establish symmetrical trimethylation patterns. In addition, Set1 coordinates with class II histone deacetylases to repress transcription and assemble heterochromatin, indicating that its recruitment and activity are context-dependent. Metabolic stress pathways also influence Set1C/COMPASS function, as genes involved in acid stress resistance include complex components.
Set1C/COMPASS complex and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| SETD1A | Neurodevelopmental disorders, cancer | Knockout and point-mutation cell models |
| SETD1B | Cancer, developmental disorders | Knock-in and overexpression models |
| RBBP5 | Cancer | Knockout and rescue models |
| ASH2L | Cancer, developmental disorders | Point-mutation and knockout models |
| HCFC1 | Intellectual disability, cancer | Knock-in and knockout models |
Cancer
Set1C/COMPASS is a melanoma-enriched epigenetic vulnerability, and systematic multivariate analysis of chromatin complex dependencies identified it as a potential therapeutic target in melanoma [2,3]. Dysregulation of H3K4 methylation by the complex is also linked to other cancers, and its subunits such as RBBP5 and ASH2L are frequently altered in tumors. The complex is therefore an attractive target for epigenetic cancer therapy [2,3].
Developmental Disorders
Mutations in mammalian Set1C/COMPASS subunits, including SETD1A and HCFC1, have been associated with neurodevelopmental disorders and intellectual disability. These findings highlight the importance of H3K4 methylation in brain development and gene regulation.
Metabolic Stress and Tumor Microenvironment
Genes involved in metabolic acid stress resistance in yeast include Set1C/COMPASS components, and these genes have potential as cancer targets because tumor cells often face acidic stress. This suggests that the complex may help cancer cells adapt to metabolic challenges.
Epithelial-Mesenchymal Transition and Fibrosis
Long noncoding RNA expression profiles related to epithelial-mesenchymal transition in keloids have been studied, and while Set1C/COMPASS is not directly implicated in that study, the complex is broadly relevant to chromatin regulation in fibrotic diseases. Further research is needed to establish direct links.
From Set1C/COMPASS complex-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does loss of Set1C/COMPASS catalytic activity affect H3K4 methylation? | Knockout of SETD1A/SETD1B or yeast Set1 |
| Does a specific point mutation in a subunit alter complex assembly? | Point-mutation knock-in cell lines |
| Can a tagged subunit be used to purify the complex? | Tagged knock-in (e.g., FLAG, HA) |
| Does overexpression of a subunit drive oncogenic phenotypes? | Overexpression cell models [2,3] |
| Which genes depend on Set1C/COMPASS for expression? | CRISPR knockout followed by RNA-seq |
| Does Set1C/COMPASS loss sensitize melanoma to therapy? | Knockout in melanoma cell lines [2,3] |
How to Study the Set1C/COMPASS complex Process
| Method | What It Measures | Typical Application |
|---|---|---|
| RNA-seq | Transcriptome changes | Assess gene expression after knockout |
| ChIP-seq | H3K4 methylation and subunit occupancy | Map chromatin marks |
| AP-MS | Protein-protein interactions | Identify complex subunits |
| CRISPR screen | Gene dependencies | Find context-specific vulnerabilities [2,3] |
| Western blot | Protein levels and modifications | Validate knockout and overexpression |
| Immunofluorescence | Subcellular localization | Study complex assembly |
| Yeast growth assays | Stress resistance | Test acid stress phenotypes |
Genomic and Transcriptomic Profiling
RNA-seq and ChIP-seq are used to measure changes in gene expression and H3K4 methylation upon Set1C/COMPASS perturbation. These methods help define the complex's target genes and its role in transcription.
Proteomics and Complex Purification
Affinity purification coupled with mass spectrometry (AP-MS) identifies subunits and interactors of Set1C/COMPASS. Tagged knock-in cell lines expressing epitope-tagged subunits enable robust purification.
Functional Genomics Screens
CRISPR library screens and systematic multivariate analyses can identify dependencies on Set1C/COMPASS, as shown in melanoma studies [2,3]. These screens link the complex to specific cancer contexts [2,3].
Yeast Genetics and Stress Assays
Yeast models are used to study Set1C/COMPASS in metabolic acid stress resistance and heterochromatin assembly [6,8]. Genetic knockouts and point mutations in yeast subunits reveal conserved functions [1,6].
How CRISPR Can Be Used to Study GO:0048188 Set1C/COMPASS complex
Knockout
CRISPR knockout of Set1C/COMPASS subunits such as SETD1A, SETD1B, RBBP5 or ASH2L is used to abolish complex function and measure effects on H3K4 methylation, gene expression and cell growth. Knockout models are essential for identifying dependent genes and pathways.
Point Mutation
Point mutations can be introduced into catalytic or scaffold subunits to dissect specific residues required for methyltransferase activity or complex assembly. Such models help separate enzymatic from non-enzymatic functions.
Knock-in
Knock-in of epitope tags (e.g., FLAG, HA) or fluorescent proteins allows purification and imaging of endogenous Set1C/COMPASS complexes. Tagged knock-in lines are valuable for proteomics and live-cell studies.
Overexpression
Overexpression of wild-type or mutant subunits can reveal gain-of-function phenotypes and drive oncogenic transformation in cancer models [2,3]. Overexpression models are used to test whether increased complex activity promotes tumorigenesis [2,3].
How EDITGENE Supports Set1C/COMPASS complex Research
Researchers studying Set1C/COMPASS complex-related genes often need to determine whether a candidate gene is causally involved in chromatin regulation, disease or drug response. EDITGENE provides CRISPR-based cell model services to enable such functional studies with high precision and reproducibility.
Contact EDITGENE today to design your custom CRISPR model for Set1C/COMPASS complex research.
Frequently Asked Questions About Set1C/COMPASS complex
What is the Set1C/COMPASS complex?
The Set1C/COMPASS complex (GO:0048188) is a conserved histone H3 methyltransferase complex that catalyzes H3K4 methylation and regulates transcription and chromatin structure.
What genes are involved in the Set1C/COMPASS complex?
In yeast, genes include SET1, SHG1, SDC1, SWD1, SWD2, SWD3, SPP1 and BRE2; in mammals, SETD1A, SETD1B, WDR5, WDR82, RBBP5, ASH2L, CXXC1, HCFC1 and DPY30.
What is the function of GO:0048188?
It catalyzes methylation of histone H3, primarily at lysine 4, and also has H3K4 methylation-independent roles in heterochromatin assembly and transcriptome repression [1,6].
Is Set1C/COMPASS complex conserved?
Yes, the complex is conserved from Saccharomyces cerevisiae to mammals, with homologous subunits.
How is Set1C/COMPASS complex regulated?
It is regulated by cotranslational assembly, by the Jhd2 demethylase, and by coordination with histone deacetylases [4,5,6].
What diseases are associated with Set1C/COMPASS complex?
It is linked to melanoma and other cancers, as well as neurodevelopmental disorders [1,2,3].
What is the role of SETD1A in the complex?
SETD1A is the catalytic subunit in mammals that methylates H3K4.
How can I study Set1C/COMPASS complex in the lab?
Common methods include CRISPR knockout, ChIP-seq, RNA-seq, AP-MS and functional screens [1,2,3].
What is the difference between Set1C and COMPASS?
Set1C and COMPASS are synonyms for the same complex, with COMPASS standing for Complex of Proteins Associated with Set1.
Why is Set1C/COMPASS a cancer target?
It is a melanoma-enriched epigenetic vulnerability and its subunits are frequently altered in cancers [2,3].
Conclusion
The Set1C/COMPASS complex (GO:0048188) is a conserved H3K4 methyltransferase that plays central roles in transcription, heterochromatin assembly and genome regulation [1,6]. Its dimeric architecture and coordination with demethylases ensure precise epigenetic marking. Emerging evidence links the complex to melanoma and other cancers, making it a promising therapeutic target [2,3]. CRISPR-based cell models and functional genomics are powerful tools to dissect its mechanisms and disease relevance.
References
- 1. Mikheyeva IV et al.. 2014. Multifaceted genome control by Set1 Dependent and Independent of H3K4 methylation and the Set1C/COMPASS complex.. PLoS Genet 10(10):e1004740 PMID: 25356590
- 2. Camacho LQ et al.. 2026. Systematic multivariate analysis of chromatin complex dependencies reveals Set1C/COMPASS as a melanoma-enriched epigenetic vulnerability.. bioRxiv PMID: 41726895
- 3. Camacho LQ et al.. 2026. Systematic multivariate analysis of chromatin complex dependencies reveals Set1C/COMPASS as a melanoma-enriched epigenetic vulnerability.. PLoS Comput Biol 22(8):e1014018 PMID: 42658887
- 4. Choudhury R et al.. 2019. The Set1 complex is dimeric and acts with Jhd2 demethylation to convey symmetrical H3K4 trimethylation.. Genes Dev 33(9-10):550-564 PMID: 30842216
- 5. Halbach A et al.. 2009. Cotranslational assembly of the yeast SET1C histone methyltransferase complex.. EMBO J 28(19):2959-70 PMID: 19713935
- 6. Lorenz DR et al.. 2014. Heterochromatin assembly and transcriptome repression by Set1 in coordination with a class II histone deacetylase.. Elife 3:e04506 PMID: 25497836
- 7. Chen Z et al.. 2022. Detection and analysis of long noncoding RNA expression profiles related to epithelial-mesenchymal transition in keloids.. Biomed Eng Online 21(1):2 PMID: 35012558
- 8. Shin JJ et al.. 2016. Systematic identification of genes involved in metabolic acid stress resistance in yeast and their potential as cancer targets.. Dis Model Mech 9(9):1039-49 PMID: 27519690
