GO:0008276 protein methyltransferase activity: Mechanism, Genes and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0008276 (protein methyltransferase activity) describes the catalysis of methyl group transfer from S-adenosylmethionine to protein substrates, a core epigenetic and signaling modification.
• Protein methyltransferases include lysine methyltransferases (KMTs) and arginine methyltransferases (PRMTs), which regulate chromatin, transcription, and signal transduction [1,2].
• PRMT5 is a major type II arginine methyltransferase that controls growth regulation, apoptosis, hypoxia signaling, and immune transcription [3,7,8].
• Dysregulated protein methylation is linked to cancer, radioresistance, and altered growth factor signaling, making these enzymes therapeutic targets [4,6].
• CRISPR knockout, point mutation, knock-in, and overexpression models enable causal dissection of methyltransferase function in disease.
• High-resolution profiling methods such as ChIP-seq and mass spectrometry have mapped histone methylation landscapes genome-wide.
Description
Protein methyltransferase activity (GO:0008276) is a fundamental enzymatic function that transfers a methyl group from S-adenosylmethionine (SAM) to specific amino acid residues on target proteins, thereby altering their stability, interactions, or catalytic activity. This modification is central to epigenetic regulation, as histone methylation directly impacts chromatin structure and gene expression programs. Beyond histones, protein methyltransferases modify transcription factors, signaling receptors, and metabolic enzymes, placing them at the intersection of multiple cellular pathways [2,4]. Researchers study GO:0008276 to understand how post-translational methylation controls normal development and how its dysregulation contributes to diseases such as cancer, immune disorders, and metabolic syndromes [3,6]. The growing availability of CRISPR-based models and high-throughput profiling tools has accelerated functional annotation of individual methyltransferases and their substrates.
protein methyltransferase activity At A Glance
| GO ID | GO:0008276 |
|---|---|
| GO term | protein methyltransferase activity |
| Ontology | molecular_function |
| Synonym | protein methylase activity |
| Major function | Transfer of a methyl group (CH3-) to a protein substrate |
| Common substrates | Lysine and arginine residues on histones and non-histone proteins |
| Methyl donor | S-adenosylmethionine (SAM) |
| Representative enzymes | PRMT5, E2F-1-associated methyltransferases, METTL13 |
| Associated processes | Chromatin remodeling, transcription regulation, signal transduction, apoptosis |
What Is GO:0008276?
According to the Gene Ontology, GO:0008276 (protein methyltransferase activity) is defined as the catalysis of the transfer of a methyl group (CH3-) to a protein. This molecular function encompasses enzymes that use S-adenosylmethionine as the methyl donor and target specific amino acid side chains, most commonly lysine and arginine residues, on protein substrates [1,2].
Why Is protein methyltransferase activity Important in Cell Biology?
Protein methyltransferase activity is essential for dynamic regulation of the proteome, influencing nearly every aspect of cell biology from gene transcription to signal transduction [1,2]. Because methylation can be reversed by demethylases, it provides a reversible switch for controlling protein function in response to cellular cues. Dysregulation of these enzymes is increasingly recognized in cancer, immune evasion, and therapy resistance, making them attractive targets for drug discovery and functional genomics [4,6].
• Controls chromatin structure and gene expression through histone methylation.
• Regulates transcription factor activity, including E2F-1 and CIITA-dependent MHC II transcription [2,3].
• Modulates receptor tyrosine kinase signaling, such as EGFR-mediated ERK activation.
• Influences apoptosis and survival pathways, including TRAIL-induced apoptosis.
• Participates in hypoxia-inducible factor 1 (HIF-1) signaling.
• Contributes to radioresistance and DNA damage repair in cancer cells.
• Is implicated in tumor-promoting roles of dual methyltransferases like METTL13.
• Provides reversible post-translational marks that can be targeted therapeutically [1,4].
• Enables high-resolution mapping of epigenetic marks for biomarker discovery.
• Serves as a model for studying enzyme-substrate specificity and catalytic mechanisms.
What Happens During protein methyltransferase activity?
Substrate recognition and binding
In simple terms: The enzyme first finds and grabs the protein it needs to modify.
Protein methyltransferases recognize specific sequence motifs or post-translationally modified states on target proteins. For example, PRMT5 binds to the TRAIL receptor and other substrates through distinct interaction domains. The binding step ensures that methylation occurs at precise residues, such as arginine 1175 in EGFR.
Methyl group transfer from SAM
In simple terms: The enzyme takes a methyl group from a donor molecule and attaches it to the target protein.
Using S-adenosylmethionine (SAM) as the methyl donor, the enzyme catalyzes the transfer of a CH3- group to the target amino acid. This reaction is the defining catalytic event of GO:0008276. The transfer can occur once or multiple times, leading to mono-, di-, or tri-methylation of lysine residues or mono- or di-methylation of arginine residues [1,2].
Conformational change and product release
In simple terms: After adding the methyl group, the enzyme releases the modified protein, which may change its shape or activity.
Methylation often induces conformational changes in the substrate that alter its interactions with binding partners or its catalytic activity. For instance, arginine methylation of E2F-1 controls its growth regulatory functions. The modified protein is then released to participate in downstream processes such as transcription or signal transduction [3,4].
Integration with cellular signaling
In simple terms: The methylation mark is read by other proteins to trigger specific cellular responses.
Methyl marks are recognized by reader domains that recruit effector complexes. In hypoxia signaling, PRMT5 is an essential component of the HIF-1 pathway, linking methylation to oxygen sensing. Similarly, PRMT5 regulates CIITA-dependent MHC II transcription, demonstrating crosstalk between methylation and immune gene expression.
Key Genes Involved in GO:0008276 protein methyltransferase activity
The following genes encode protein methyltransferases or key substrates that define the functional landscape of GO:0008276.
| Gene | Major Role | Research Relevance |
|---|---|---|
| PRMT5 | Type II arginine methyltransferase | Regulates growth, apoptosis, hypoxia signaling, and immune transcription [3,7,8] |
| E2F-1 | Transcription factor and methylation substrate | Arginine methylation controls its growth regulatory activity |
| EGFR | Receptor tyrosine kinase and methylation substrate | Arg 1175 methylation crosstalks with Tyr 1173 phosphorylation to modulate ERK activation |
| METTL13 | Dual protein methyltransferase | Tumor-promoting role in C. elegans and potential cancer relevance |
| CIITA | Transcription factor regulated by PRMT5 | Controls MHC II transcription and immune responses |
| HIF-1 | Hypoxia-inducible factor complex | Requires PRMT5 for signaling under low oxygen |
| TRAIL receptor | Apoptosis receptor | PRMT5 binding inhibits TRAIL-induced apoptosis via NF-kappaB |
| STC2 | Stanniocalcin 2 | Activates PRMT5 to induce radioresistance and DNA damage repair |
| Histone H3 | Chromatin component | Methylation marks map to active and repressed genomic regions |
| Histone H4 | Chromatin component | Methylation profiling reveals epigenetic landscapes |
| PRMT1 | Type I arginine methyltransferase | Broadly involved in cellular methylation but not directly cited in this list |
| SETD7 | Lysine methyltransferase | Methylates non-histone proteins but not directly cited in this list |
| SMYD2 | Lysine methyltransferase | Methylates p53 and other substrates but not directly cited in this list |
| EZH2 | Polycomb repressive complex methyltransferase | Histone H3K27 methylation but not directly cited in this list |
| DOT1L | Histone H3K79 methyltransferase | Not directly cited in this list |
| NSD2 | Histone H3K36 methyltransferase | Not directly cited in this list |
| METTL3 | m6A RNA methyltransferase | Not directly cited in this list |
How Is protein methyltransferase activity Regulated?
Protein methyltransferase activity is regulated at multiple levels, including enzyme expression, post-translational modifications, and availability of SAM. PRMT5 activity is modulated by interacting proteins such as STC2, which activates PRMT5 to promote radioresistance. Hypoxia signaling through HIF-1 requires PRMT5, indicating oxygen-dependent regulation. Additionally, crosstalk with phosphorylation, as seen for EGFR Arg 1175 methylation and Tyr 1173 phosphorylation, provides a switch for signal transduction.
protein methyltransferase activity and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| PRMT5 | Radioresistance in esophageal squamous cell carcinoma | Knockout or overexpression in cancer cell lines followed by irradiation |
| METTL13 | Tumor promotion in C. elegans | Knockout and overexpression in C. elegans models |
| E2F-1 | Growth regulation and cancer | Point mutation of methylation sites in mammalian cells |
| EGFR | Lung cancer and ERK signaling | Knock-in of methylation-deficient EGFR mutants |
| CIITA | Immune evasion and MHC II regulation | Knockout of PRMT5 in immune cell lines |
Cancer and therapy resistance
Dysregulated protein methyltransferase activity contributes to tumor growth and therapy resistance. PRMT5 activation by STC2 induces radioresistance through enhanced DNA damage repair and inhibition of ferroptosis in esophageal squamous cell carcinoma. METTL13 exhibits tumor-promoting roles in model organisms, suggesting its potential as a cancer target.
Apoptosis and immune evasion
PRMT5 inhibits TRAIL-induced apoptosis by activating NF-kappaB, allowing cancer cells to evade programmed cell death. PRMT5 also regulates CIITA-dependent MHC II transcription, linking methylation to immune recognition and potential immunotherapy resistance.
Growth factor signaling and proliferation
Arginine methylation of E2F-1 controls its growth regulatory functions, and methylation of EGFR at Arg 1175 modulates downstream ERK activation, highlighting how methylation directly impacts proliferative signaling [2,4].
From protein methyltransferase activity-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does loss of PRMT5 affect radioresistance? | CRISPR knockout of PRMT5 in cancer cell lines |
| How does E2F-1 methylation regulate growth? | Point mutation of arginine methylation sites in E2F-1 |
| What is the role of METTL13 in tumor promotion? | Knockout and overexpression in C. elegans |
| Does EGFR Arg 1175 methylation affect ERK signaling? | Knock-in of methylation-deficient EGFR |
| How does PRMT5 regulate MHC II transcription? | Knockout of PRMT5 in antigen-presenting cells |
| Is PRMT5 required for HIF-1 signaling? | Knockout or knockdown under hypoxia |
How to Study the protein methyltransferase activity Process
| Method | What It Measures | Typical Application |
|---|---|---|
| ChIP-seq | Genome-wide histone methylation patterns | Mapping epigenetic landscapes |
| Mass spectrometry | Protein methylation sites and stoichiometry | Substrate identification and quantification [1,4] |
| CRISPR knockout screens | Gene essentiality and drug resistance | Identifying methyltransferase dependencies [5,6] |
| In vitro methyltransferase assay | Enzymatic activity and substrate specificity | Validating GO:0008276 function |
| Western blot with methylation-specific antibodies | Levels of specific methyl marks | Confirming target modification [2,4] |
| Co-immunoprecipitation | Protein-protein interactions | Identifying methyltransferase complexes [3,7] |
| RNA-seq | Transcriptional changes upon perturbation | Linking methylation to gene expression [3,8] |
| Immunofluorescence | Subcellular localization of methyl marks | Visualizing methylation dynamics |
Chromatin immunoprecipitation sequencing (ChIP-seq)
ChIP-seq using antibodies against methylated histones provides high-resolution maps of histone methylation across the genome, revealing active and repressed regions.
Mass spectrometry-based proteomics
Mass spectrometry can identify methylation sites on proteins and quantify changes in methylation status upon genetic perturbation, enabling substrate discovery for methyltransferases [1,4].
CRISPR-based functional screens
Pooled CRISPR knockout libraries targeting methyltransferases can identify genes required for cell growth, drug resistance, or immune evasion, as demonstrated for PRMT5 and METTL13 [5,6].
Biochemical methyltransferase assays
In vitro assays using recombinant enzymes and radiolabeled SAM measure catalytic activity and substrate specificity, providing direct evidence for GO:0008276.
How CRISPR Can Be Used to Study GO:0008276 protein methyltransferase activity
Knockout
CRISPR knockout of methyltransferase genes such as PRMT5 or METTL13 enables loss-of-function studies to assess their role in cell growth, apoptosis, and therapy response [5,6].
Point Mutation
Introducing point mutations at specific methylation sites, such as EGFR Arg 1175 or E2F-1 arginine residues, allows precise dissection of methylation-dependent signaling without altering enzyme expression [2,4].
Knock-in
Knock-in of tagged or mutant methyltransferases can be used to track localization, interaction partners, and catalytic activity in live cells [1,3].
Overexpression
Overexpression of wild-type or catalytically dead methyltransferases helps determine sufficiency and dominant-negative effects in disease models [5,7].
How EDITGENE Supports protein methyltransferase activity Research
Researchers studying protein methyltransferase activity-related genes often need to determine whether a candidate gene is causally involved in a specific phenotype, such as drug resistance or altered transcription. EDITGENE provides end-to-end CRISPR services to generate precisely engineered cell models that answer these questions.
Contact EDITGENE today to design your custom CRISPR model for protein methyltransferase activity research.
Frequently Asked Questions About protein methyltransferase activity
What is protein methyltransferase activity?
It is the enzymatic function defined by GO:0008276 that transfers a methyl group from S-adenosylmethionine to a protein substrate.
What genes are involved in protein methyltransferase activity?
Key genes include PRMT5, E2F-1, EGFR, METTL13, and CIITA, among others [2,3,4,5].
How does protein methylation regulate gene expression?
Methylation of histones and transcription factors alters chromatin structure and DNA binding, thereby controlling transcription [1,2].
What diseases are linked to protein methyltransferase activity?
Cancer, radioresistance, immune evasion, and growth disorders are associated with dysregulated methyltransferases [3,4,6].
What is the role of PRMT5 in cancer?
PRMT5 promotes radioresistance, inhibits apoptosis, and regulates immune transcription, making it a therapeutic target [6,7,3].
How can I study protein methyltransferase activity in the lab?
Use CRISPR knockout, point mutation, knock-in, overexpression, ChIP-seq, mass spectrometry, and biochemical assays [1,4,5].
What is the difference between lysine and arginine methylation?
Lysine methylation can be mono-, di-, or tri-methylated, while arginine methylation is typically mono- or di-methylated, affecting different reader proteins [1,2].
Can protein methylation be reversed?
Yes, demethylases remove methyl groups, making methylation a dynamic and reversible modification.
What is the role of METTL13 in tumors?
METTL13 exhibits tumor-promoting activity in C. elegans models, suggesting a conserved role in growth control.
How does EGFR methylation affect signaling?
Methylation at Arg 1175 crosstalks with phosphorylation at Tyr 1173 to modulate EGFR-mediated ERK activation.
Conclusion
Protein methyltransferase activity (GO:0008276) is a central post-translational modification that regulates chromatin, transcription, and signal transduction. Its dysregulation is implicated in cancer, immune evasion, and therapy resistance, making it a high-priority target for functional genomics and drug discovery [1,4,6]. CRISPR-based models and advanced profiling methods continue to uncover new substrates and disease links, offering opportunities for therapeutic intervention [5,8].
References
- 1. Barski A et al.. 2007. High-resolution profiling of histone methylations in the human genome.. Cell 129(4):823-37 PMID: 17512414
- 2. Cho EC et al.. 2012. Arginine methylation controls growth regulation by E2F-1.. EMBO J 31(7):1785-97 PMID: 22327218
- 3. Fan Z et al.. 2016. The arginine methyltransferase PRMT5 regulates CIITA-dependent MHC II transcription.. Biochim Biophys Acta 1859(5):687-96 PMID: 26972221
- 4. Hsu JM et al.. 2011. Crosstalk between Arg 1175 methylation and Tyr 1173 phosphorylation negatively modulates EGFR-mediated ERK activation.. Nat Cell Biol 13(2):174-81 PMID: 21258366
- 5. Engelfriet ML et al.. 2023. Characterization of the biochemical activity and tumor-promoting role of the dual protein methyltransferase METL-13/METTL13 in Caenorhabditis elegans.. PLoS One 18(6):e0287558 PMID: 37347777
- 6. Jiang K et al.. 2023. STC2 activates PRMT5 to induce radioresistance through DNA damage repair and ferroptosis pathways in esophageal squamous cell carcinoma.. Redox Biol 60:102626 PMID: 36764215
- 7. Tanaka H et al.. 2009. PRMT5, a novel TRAIL receptor-binding protein, inhibits TRAIL-induced apoptosis via nuclear factor-kappaB activation.. Mol Cancer Res 7(4):557-69 PMID: 19372584
- 8. Lim JH et al.. 2012. Protein arginine methyltransferase 5 is an essential component of the hypoxia-inducible factor 1 signaling pathway.. Biochem Biophys Res Commun 418(2):254-9 PMID: 22266372
