GO:0008999 protein-N-terminal-alanine acetyltransferase activity: Mechanism, Genes and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0008999 describes the enzymatic activity that transfers an acetyl group from acetyl-CoA to the N-terminal alanine of a protein, forming an N(alpha)-acetyl-L-alanyl residue.
• This activity is a molecular_function, not a process or location; it is measured biochemically as acetyl-CoA-dependent N-terminal alanine acetylation.
• The reaction consumes acetyl-CoA and releases CoA and a proton, making it a direct reader of cellular acetyl-CoA pools.
• N-terminal acetylation can alter protein stability, localization and interactions, and is therefore relevant to proteostasis and disease.
• Key experimental approaches include acetyltransferase assays, mass spectrometry, ribosome profiling and CRISPR-based perturbation of candidate genes.
• CRISPR knockout, point-mutation, knock-in and overexpression models allow causal testing of genes annotated to this activity.
Description
GO:0008999, protein-N-terminal-alanine acetyltransferase activity, is a molecular_function term in the Gene Ontology that captures a specific enzymatic reaction: the acetyl-CoA-dependent acetylation of the N-terminal alanine residue of a protein. This activity belongs to the broader class of N-terminal acetyltransferases (NATs), enzymes that modify the alpha-amino group of a protein's first amino acid and thereby change its chemical and biological properties. Because the reaction consumes acetyl-CoA and produces CoA, it directly links protein modification to central metabolic pools. Researchers study this activity to understand how co-translational and post-translational N-terminal acetylation influences protein fate, including stability, subcellular targeting and interaction networks. The term is also relevant to synthetic biology and epigenome engineering, where acetyltransferase domains are fused to programmable DNA-binding proteins to activate transcription. In this article we define GO:0008999, outline its mechanism, list genes and proteins associated with the activity, and describe experimental models and methods used to investigate it.
protein-N-terminal-alanine acetyltransferase activity At A Glance
| GO ID | GO:0008999 |
|---|---|
| GO term | protein-N-terminal-alanine acetyltransferase activity |
| Ontology | molecular_function |
| Synonym | acetyl-CoA:ribosomal-protein-L-alanine N-acetyltransferase activity; peptide-alanine-alpha-N-acetyltransferase activity; ribosomal-protein-alanine N-acetyltransferase activity; ribosomal protein S18 acetyltransferase activity |
| Major function | Transfer of an acetyl group from acetyl-CoA to the N-terminal alanine of a protein substrate |
| Reaction | acetyl-CoA + N-terminal L-alanyl-[protein] = CoA + H+ + N-terminal N(alpha)-acetyl-L-alanyl-[protein] |
| Substrate | N-terminal L-alanyl-[protein] |
| Cofactor | acetyl-CoA |
| Products | CoA, H+, N-terminal N(alpha)-acetyl-L-alanyl-[protein] |
What Is GO:0008999?
GO:0008999 is defined as catalysis of the reaction: acetyl-CoA + N-terminal L-alanyl-[protein] = CoA + H+ + N-terminal N(alpha)-acetyl-L-alanyl-[protein]. In other words, the enzyme takes an acetyl group from acetyl-CoA and attaches it to the free alpha-amino group of an N-terminal alanine on a protein substrate, releasing coenzyme A and a proton. This is a molecular_function annotation: it describes what the enzyme does at the chemical level, not where it acts or which larger process it belongs to.
Why Is protein-N-terminal-alanine acetyltransferase activity Important in Cell Biology?
GO:0008999 is important because N-terminal acetylation is one of the most common protein modifications in eukaryotes and directly affects protein stability, folding, localization and interactions. The activity also connects protein modification to acetyl-CoA metabolism, so changes in nutrient status or metabolic flux can influence the modification landscape. In research, the term provides a precise annotation for enzymes and domains used in functional genomics, including acetyltransferase domains engineered into CRISPR-based activators. Understanding this activity helps explain how cells maintain proteostasis and how its dysregulation may contribute to disease.
• N-terminal acetylation can create or destroy degrons, thereby controlling protein half-life.
• The modification can influence protein-protein interactions and complex assembly.
• It can affect subcellular localization by masking or presenting targeting signals.
• The activity links protein modification to acetyl-CoA availability and metabolic state.
• Acetyltransferase domains are used in epigenome editing to activate endogenous genes.
• Dysregulation of acetylation pathways has been linked to cancer and metabolic disease.
• The activity is relevant to ribosome biology because ribosomal proteins can be N-terminally acetylated.
• It provides a target for chemical biology and inhibitor development.
• CRISPR screens can identify genes required for this activity in specific cell states.
• Mass spectrometry-based proteomics enables global mapping of N-terminal acetylation.
Molecular Mechanism of protein-N-terminal-alanine acetyltransferase activity
Substrate recognition and binding
In simple terms: The enzyme first grabs the target protein by its N-terminal alanine.
The enzyme binds an N-terminal L-alanyl-[protein] substrate, positioning the alpha-amino group of the N-terminal alanine for catalysis. Specificity for alanine at the N-terminus is a defining feature of this activity, and the enzyme must distinguish the N-terminal residue from internal lysines.
Acetyl-CoA binding and acetyl transfer
In simple terms: The enzyme takes an acetyl group from acetyl-CoA and puts it on the protein.
Acetyl-CoA binds the active site and donates its acetyl group to the N-terminal alpha-amino group, forming N(alpha)-acetyl-L-alanyl-[protein] and releasing CoA. This is a direct acetyl transfer reaction, not a multi-step activation, and it produces a proton as a byproduct.
Product release and catalytic cycle
In simple terms: After the acetyl group is attached, the modified protein and CoA leave, and the enzyme can work again.
Following acetyl transfer, the N(alpha)-acetylated protein and CoA are released, allowing the enzyme to catalyze another round. The reaction is therefore catalytic and depends on continued acetyl-CoA supply.
Cofactor and metabolic coupling
In simple terms: The reaction uses acetyl-CoA, so it is tied to the cell's metabolic state.
Because acetyl-CoA is the acetyl donor, the activity is sensitive to acetyl-CoA levels and to pathways that generate or consume it. This couples protein N-terminal acetylation to nutrient availability and metabolic signaling.
Regulation and competition with other modifications
In simple terms: Other modifications can compete for the same N-terminal site.
The N-terminal alpha-amino group can be subject to other modifications, and acetylation may compete with them. Regulatory inputs that alter enzyme expression, localization or acetyl-CoA availability can therefore change the modification state of target proteins.
Key Genes Involved in GO:0008999 protein-N-terminal-alanine acetyltransferase activity
The following genes and proteins are associated with N-terminal acetylation biology and are useful for experimental studies of GO:0008999.
| Gene | Major Role | Research Relevance |
|---|---|---|
| NAA10 | Catalytic subunit of the NatA N-terminal acetyltransferase complex | Core enzyme for N-terminal alanine acetylation; knockout affects many substrates |
| NAA15 | Auxiliary subunit of the NatA complex | Required for NatA activity and substrate selection |
| NAA11 | N-terminal acetyltransferase family member | Tissue-specific roles and substrate specificity |
| NAA20 | Catalytic subunit of NatB | N-terminal acetylation of Met-Glu/Asp substrates |
| NAA25 | Auxiliary subunit of NatB | Complex assembly and substrate targeting |
| NAA30 | Catalytic subunit of NatC | N-terminal acetylation of Met-Leu/Ile/Phe substrates |
| NAA35 | Auxiliary subunit of NatC | Complex function and ribosome association |
| NAA38 | Auxiliary subunit of NatC | Substrate recognition and complex stability |
| NAA40 | N-terminal acetyltransferase | Acetylation of specific N-terminal residues |
| NAA50 | N-terminal acetyltransferase | Acetylation of Met-Gln and other substrates |
| NAA60 | Golgi-localized N-terminal acetyltransferase | Post-translational N-terminal acetylation |
| HAT1 | Histone acetyltransferase | Acetyl-CoA-dependent acetylation and chromatin biology |
| EP300 | Histone acetyltransferase and transcriptional coactivator | Acetyltransferase domain used in epigenome editing |
| CREBBP | Histone acetyltransferase and coactivator | Acetyltransferase activity and transcriptional regulation |
| RPS18 | Ribosomal protein S18 | Synonym links this activity to ribosomal protein acetylation |
| RPL3 | Ribosomal protein L3 | Ribosome-associated N-terminal acetylation |
| RPS5 | Ribosomal protein S5 | Model substrate for N-terminal modification studies |
How Is protein-N-terminal-alanine acetyltransferase activity Regulated?
The activity is regulated at multiple levels. Enzyme abundance and complex assembly control how much active acetyltransferase is available, while acetyl-CoA availability sets the supply of acetyl donor. Because N-terminal acetylation can occur co-translationally, ribosome association and translation rate can influence substrate access. Post-translational modifications of the enzymes themselves and their interaction partners can further tune activity. In metabolic contexts, changes in acetyl-CoA flux can shift the modification landscape.
protein-N-terminal-alanine acetyltransferase activity and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| NAA10 | Developmental disorders and proteostasis | Knockout and point-mutation cell models |
| NAA15 | Neurodevelopmental phenotypes | Knock-in and knockout models |
| EP300 | Cancer and transcriptional dysregulation | Overexpression and knockout models |
| CREBBP | Cancer and developmental disorders | Point-mutation and knockout models |
| RPS18 | Ribosome biology and ribosomopathy | Tagged knock-in and ribosome profiling |
Cancer and metabolic reprogramming
Altered acetylation pathways have been linked to cancer and metabolic reprogramming, where changes in acetyl-CoA availability and acetyltransferase activity can affect gene expression and cell growth. The activity is therefore studied in models of tumor metabolism and epigenetics.
Neurodegeneration and proteostasis
N-terminal acetylation can influence protein stability and aggregation, making it relevant to neurodegenerative conditions characterized by proteostasis failure. Experimental models often use knockout or point-mutation approaches to test causal roles.
Ribosomopathies and ribosomal protein modification
Because ribosomal proteins can be N-terminally acetylated, defects in this activity may intersect with ribosome assembly and ribosomopathy phenotypes. Research models include ribosomal protein tagging and ribosome profiling.
Developmental and cardiac stress responses
Acetylation-dependent transcriptional programs contribute to developmental and stress responses, including cardiac metabolic reprogramming. Studying this activity in such contexts can reveal how metabolic and epigenetic signals converge.
From protein-N-terminal-alanine acetyltransferase activity-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Is a candidate gene required for N-terminal alanine acetylation? | CRISPR knockout cell line |
| Does a specific catalytic residue mediate acetyl transfer? | Point-mutation knock-in |
| Where does the enzyme act in the cell? | Tagged knock-in with fluorescent or affinity tag |
| Does overexpression change substrate modification? | Overexpression cell model |
| Which genes modify the phenotype? | CRISPR library screening |
| What are the global substrates? | Proteomics and mass spectrometry |
How to Study the protein-N-terminal-alanine acetyltransferase activity Process
| Method | What It Measures | Typical Application |
|---|---|---|
| Acetyltransferase assay | Enzyme activity and substrate specificity | In vitro validation of GO:0008999 |
| Mass spectrometry | N-terminal acetylation sites and stoichiometry | Global substrate mapping |
| Ribosome profiling | Translation and co-translational modification | Mechanism studies |
| RNA-seq | Transcriptional consequences of perturbation | Knockout and overexpression models |
| Proteomics | Protein abundance and modification changes | Pathway analysis |
| Imaging | Subcellular localization of tagged enzymes | Knock-in models |
| CRISPR screen | Gene requirements and modifiers | Functional genomics |
| Co-immunoprecipitation | Protein interactions and complex assembly | Enzyme complex studies |
Biochemical acetyltransferase assays
In vitro assays using recombinant enzyme, acetyl-CoA and peptide or protein substrates measure the specific activity and substrate specificity of GO:0008999. These assays can be coupled to detection of CoA release or radiolabeled acetyl groups.
Mass spectrometry and proteomics
Mass spectrometry identifies N-terminal acetylation on proteins and maps substrate sites, enabling global analysis of the activity. Enrichment of N-terminal peptides improves coverage of this modification.
Ribosome profiling and translation studies
Ribosome profiling can reveal co-translational N-terminal acetylation and how translation rate affects substrate modification. It is often combined with knockout or knockdown of candidate genes.
CRISPR-based perturbation and screening
CRISPR knockout, point-mutation and library screening allow causal testing of genes annotated to this activity and discovery of modifiers. These approaches are complemented by transcriptomic and proteomic readouts.
How CRISPR Can Be Used to Study GO:0008999 protein-N-terminal-alanine acetyltransferase activity
Knockout
CRISPR knockout of candidate genes such as NAA10 or NAA15 eliminates the activity and reveals its cellular functions. Knockout models are used to test effects on protein stability, localization and transcriptomes.
Point Mutation
Point mutations in catalytic residues or substrate-binding sites can separate acetyltransferase activity from other functions. These models help establish causality for specific residues.
Knock-in
Knock-in of tags or reporters allows visualization and purification of the enzyme and its substrates. Tagged knock-in models are useful for localization and interaction studies.
Overexpression
Overexpression of the enzyme or its subunits can amplify the activity and reveal dose-dependent effects on substrates. It is often combined with proteomics to identify modified proteins.
How EDITGENE Supports protein-N-terminal-alanine acetyltransferase activity Research
Researchers studying protein-N-terminal-alanine acetyltransferase activity-related genes often need to determine whether a candidate gene is causally involved in the modification, which substrates it targets, and how perturbation changes cell state. EDITGENE provides CRISPR-based cell models and screening services to answer these questions with publication-ready rigor.
Contact EDITGENE today to design your custom CRISPR model for protein-N-terminal-alanine acetyltransferase activity research.
Frequently Asked Questions About protein-N-terminal-alanine acetyltransferase activity
What is GO:0008999?
GO:0008999 is the Gene Ontology molecular_function term for protein-N-terminal-alanine acetyltransferase activity, which transfers an acetyl group from acetyl-CoA to the N-terminal alanine of a protein.
What does protein-N-terminal-alanine acetyltransferase activity do?
It catalyzes the acetylation of the N-terminal alpha-amino group of an alanine residue on a protein, producing an N(alpha)-acetyl-L-alanyl protein and releasing CoA and a proton.
What genes are involved in protein-N-terminal-alanine acetyltransferase activity?
Genes encoding N-terminal acetyltransferase subunits and related acetyltransferases include NAA10, NAA15, NAA11, NAA20, NAA25, NAA30, NAA35, NAA38, NAA40, NAA50, NAA60, EP300 and CREBBP.
What is the reaction catalyzed by GO:0008999?
The reaction is acetyl-CoA + N-terminal L-alanyl-[protein] = CoA + H+ + N-terminal N(alpha)-acetyl-L-alanyl-[protein].
Which cofactor is required for protein-N-terminal-alanine acetyltransferase activity?
Acetyl-CoA is the acetyl donor and essential cofactor for the reaction.
How is protein-N-terminal-alanine acetyltransferase activity studied?
It is studied using biochemical acetyltransferase assays, mass spectrometry, ribosome profiling, proteomics and CRISPR-based perturbation.
What diseases are linked to N-terminal acetylation?
Altered acetylation pathways have been linked to cancer, metabolic reprogramming, neurodegeneration and developmental disorders.
Can CRISPR be used to study GO:0008999?
Yes, CRISPR knockout, point-mutation, knock-in and overexpression models can test the causal role of genes annotated to this activity.
What is the difference between N-terminal acetylation and lysine acetylation?
N-terminal acetylation modifies the alpha-amino group of the first amino acid, while lysine acetylation modifies the epsilon-amino group of internal lysine residues.
Why is acetyl-CoA important for this activity?
Acetyl-CoA supplies the acetyl group, so the activity is directly coupled to cellular metabolism and acetyl-CoA availability.
Conclusion
GO:0008999, protein-N-terminal-alanine acetyltransferase activity, defines a precise enzymatic reaction that modifies the N-terminus of proteins using acetyl-CoA. This activity influences protein stability, interactions and localization and is connected to metabolism and disease. Researchers can interrogate it with biochemical assays, proteomics and CRISPR-based models, and EDITGENE provides the tools to build those models efficiently.
References
- 1. Hilton IB et al.. 2015. Epigenome editing by a CRISPR-Cas9-based acetyltransferase activates genes from promoters and enhancers.. Nat Biotechnol 33(5):510-7 PMID: 25849900
- 4. Näär AM et al.. 2001. Transcriptional coactivator complexes.. Annu Rev Biochem 70:475-501 PMID: 11395415
- 5. Perissi V et al.. 1999. Factor-specific modulation of CREB-binding protein acetyltransferase activity.. Proc Natl Acad Sci U S A 96(7):3652-7 PMID: 10097092
- 6. Zhang M et al.. 2025. Transcription factor Yin-Yang 1 governs cardiac metabolic reprogramming in response to exercise or pathological stress.. Am J Physiol Heart Circ Physiol 329(4):H899-H906 PMID: 40803696
- 8. King CM et al.. 1983. Acetylation, deacetylation and acyltransfer.. Environ Health Perspect 49:43-50 PMID: 6131820
