GO:1990190 protein-N-terminal-glutamate acetyltransferase activity: Mechanism, Genes and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:1990190 describes the enzymatic activity that transfers an acetyl group from acetyl-CoA to the N-terminal glutamate of a peptide, forming N-acetyl-L-glutamate-peptide and CoA.
• This activity is distinct from lysine acetylation and is carried out by N-terminal acetyltransferases (NATs) that recognize N-terminal glutamate, such as NatC and NatF in eukaryotes.
• The reaction is part of the broader protein N-terminal acetylation machinery, which influences protein stability, localization, and interactions.
• Dysregulation of N-terminal acetylation has been linked to developmental disorders, cancer, and metabolic diseases.
• Key experimental approaches to study this activity include in vitro acetyltransferase assays, mass spectrometry, and CRISPR-based knockout or knock-in models.
• Understanding GO:1990190 provides insight into co-translational and post-translational regulation of protein function and offers potential therapeutic targets.
Description
Protein N-terminal acetylation is a prevalent modification in eukaryotes, affecting a large fraction of the proteome. The Gene Ontology term GO:1990190, protein-N-terminal-glutamate acetyltransferase activity, specifically defines the catalytic transfer of an acetyl group from acetyl-CoA to the alpha-amino group of an N-terminal glutamate residue in a peptide, yielding N-acetyl-L-glutamate-peptide and CoA. This activity is mediated by a subset of N-terminal acetyltransferases (NATs) that exhibit substrate specificity for N-terminal glutamate, such as NatC and NatF in higher eukaryotes. Unlike lysine acetylation, which typically occurs on internal residues and is reversible, N-terminal acetylation is often irreversible and occurs co-translationally, influencing protein fate. Researchers study GO:1990190 to understand how N-terminal modification affects protein stability, subcellular localization, and interactions. The modification can create or destroy degrons, thereby controlling protein half-life, and can modulate membrane association by neutralizing the positive charge of the N-terminus. In addition, N-terminal acetylation is implicated in various physiological and pathological processes, including cardiovascular function, metabolic reprogramming, and cancer. The enzymatic activity defined by GO:1990190 is therefore a critical node in the regulation of protein function and cellular homeostasis. This article provides a comprehensive overview of GO:1990190, covering its definition, biological significance, key genes, regulatory mechanisms, disease associations, and experimental methods. By integrating authoritative QuickGO data with verified PubMed literature, we aim to equip researchers with a clear understanding of this activity and its role in health and disease.
protein-N-terminal-glutamate acetyltransferase activity At A Glance
| GO ID | GO:1990190 |
|---|---|
| GO term | protein-N-terminal-glutamate acetyltransferase activity |
| Ontology | molecular_function |
| Synonym | peptide-glutamate-alpha-N-acetyltransferase activity; protein-N-terminal-glutamate-alpha-N-acetyltransferase activity |
| Definition | Catalysis of the reaction: acetyl-CoA + N-terminal L-glutamate in peptide = CoA + N-acetyl-L-glutamate-peptide. |
| Major function | Acetylation of N-terminal glutamate residues on proteins, influencing protein stability, localization, and interactions. |
| Cofactor | Acetyl-CoA |
| Substrate | N-terminal L-glutamate in peptide |
| Product | N-acetyl-L-glutamate-peptide and CoA |
What Is GO:1990190?
GO:1990190, protein-N-terminal-glutamate acetyltransferase activity, is a molecular function defined as the catalysis of the reaction: acetyl-CoA + N-terminal L-glutamate in peptide = CoA + N-acetyl-L-glutamate-peptide. In other words, it is the enzyme activity that acetylates the free alpha-amino group of an N-terminal glutamate residue on a protein or peptide, using acetyl-CoA as the acetyl donor. This activity is synonymous with peptide-glutamate-alpha-N-acetyltransferase activity and protein-N-terminal-glutamate-alpha-N-acetyltransferase activity. It is a specific type of protein N-terminal acetyltransferase activity, distinguished by its substrate preference for N-terminal glutamate.
Why Is protein-N-terminal-glutamate acetyltransferase activity Important in Cell Biology?
GO:1990190 is important because N-terminal acetylation is one of the most common protein modifications in eukaryotes, affecting a majority of cytosolic proteins. This specific activity, targeting N-terminal glutamate, contributes to the diversity of N-terminal acetylomes and regulates key cellular processes such as protein degradation, membrane targeting, and complex formation. Dysregulation of N-terminal acetyltransferases has been associated with severe developmental disorders, cancer progression, and metabolic imbalances. Moreover, the enzymatic activity is a potential drug target, as modulating N-terminal acetylation can alter protein function in disease contexts.
• Regulates protein stability by creating or destroying N-terminal degrons recognized by the ubiquitin-proteasome system.
• Influences protein subcellular localization, particularly membrane association by neutralizing N-terminal positive charge.
• Modulates protein-protein interactions and complex assembly, impacting signaling pathways.
• Plays a role in cardiovascular function and metabolic reprogramming in response to stress.
• Implicated in cancer development through altered expression or activity of N-terminal acetyltransferases.
• Contributes to the regulation of gene expression by modifying transcription factors and chromatin-associated proteins.
• Provides a mechanism for co-translational quality control and protein folding.
• Serves as a potential therapeutic target for diseases linked to N-terminal acetylation defects.
• Essential for understanding the broader N-terminal acetylome and its evolutionary conservation.
• Enables precise experimental dissection using CRISPR-based gene editing and acetyltransferase assays.
Molecular Mechanism of protein-N-terminal-glutamate acetyltransferase activity
Substrate Recognition and Binding
In simple terms: The enzyme first grabs the target protein by its N-terminal glutamate.
The catalytic subunit of the N-terminal acetyltransferase complex recognizes the N-terminal glutamate residue of a nascent polypeptide or peptide. This recognition is mediated by specific binding pockets that accommodate the negatively charged glutamate side chain, ensuring specificity over other N-terminal residues. The ribosome-associated NatC and NatF complexes in eukaryotes exemplify this specificity, with NatF being particularly adapted to N-terminal glutamate in higher eukaryotes.
Acetyl Transfer from Acetyl-CoA
In simple terms: The enzyme transfers an acetyl group from acetyl-CoA onto the glutamate.
Upon substrate binding, the enzyme catalyzes the transfer of the acetyl group from acetyl-CoA to the alpha-amino group of the N-terminal glutamate. This reaction proceeds via a ternary complex mechanism, where both substrates are bound simultaneously. The catalytic mechanism likely involves general acid-base catalysis, with conserved residues in the acetyltransferase domain facilitating the deprotonation of the amino group and stabilization of the transition state. The products are CoA and N-acetyl-L-glutamate-peptide.
Cofactors and Energetics
In simple terms: Acetyl-CoA provides the acetyl group and the energy for the reaction.
Acetyl-CoA serves as the acetyl donor and is essential for the activity. The reaction is energetically favorable due to the high-energy thioester bond in acetyl-CoA. No additional cofactors such as ATP or metal ions are required for this activity, distinguishing it from some other acetyltransferases. The enzyme operates optimally at physiological pH and temperature.
Regulation of Activity
In simple terms: The enzyme's activity can be turned up or down by cellular signals.
The activity of N-terminal glutamate acetyltransferases can be regulated at multiple levels. Expression levels of the catalytic and auxiliary subunits are controlled transcriptionally and post-translationally. Additionally, the availability of acetyl-CoA, which reflects cellular metabolic status, can influence the rate of acetylation. Phosphorylation of subunits may also modulate activity, as seen in other acetyltransferase complexes. Furthermore, interaction with the ribosome and nascent polypeptide chains couples the activity to translation.
Biological Outcomes
In simple terms: The added acetyl group changes how the protein behaves in the cell.
N-terminal acetylation by this activity can affect protein folding, stability, and interactions. For example, it can prevent the N-terminus from being recognized by E3 ubiquitin ligases, thereby extending protein half-life. It can also promote or inhibit binding to membranes or other proteins, depending on the specific protein context. These outcomes are critical for cellular processes such as apoptosis, cell cycle progression, and stress responses.
Key Genes Involved in GO:1990190 protein-N-terminal-glutamate acetyltransferase activity
The following genes encode proteins that either catalyze or regulate protein-N-terminal-glutamate acetyltransferase activity, or serve as model substrates for studying this modification.
| Gene | Major Role | Research Relevance |
|---|---|---|
| NAA30 | Catalytic subunit of NatC complex, acetylates N-terminal Met-Glu and other residues | Knockout leads to defects in protein stability and mitochondrial function |
| NAA35 | Auxiliary subunit of NatC complex | Required for NatC activity and substrate specificity |
| NAA38 | Auxiliary subunit of NatC complex | Stabilizes the complex and aids in ribosome association |
| NAA60 | Catalytic subunit of NatF, specific for N-terminal glutamate in higher eukaryotes | Knockdown affects Golgi integrity and protein trafficking |
| NAA10 | Catalytic subunit of NatA, primarily acetylates Ser/Thr/Ala N-termini | Can compensate for loss of other NATs in some contexts |
| NAA15 | Auxiliary subunit of NatA | Essential for NatA activity and development |
| NAA20 | Catalytic subunit of NatB, acetylates Met-Glu and Met-Asp N-termini | Overlaps in specificity with NatC for some substrates |
| NAA25 | Auxiliary subunit of NatB | Required for NatB function |
| NAA50 | Catalytic subunit of NatE, acetylates Met-Leu and other hydrophobic N-termini | Distinct from glutamate-specific activity |
| HYPK | Huntingtin-interacting protein K, interacts with NatA | Modulates N-terminal acetylation and apoptosis |
| HAT1 | Histone acetyltransferase, can acetylate non-histone proteins | Potential crosstalk with N-terminal acetylation |
| EP300 | Transcriptional coactivator with acetyltransferase activity | Can acetylate N-terminal regions of some proteins |
| CREBBP | CREB-binding protein, acetyltransferase | Modulates transcription factor activity via acetylation |
| YY1 | Transcription factor, regulated by acetylation | Involved in cardiac metabolic reprogramming |
| NAT8 | N-terminal acetyltransferase 8, testis-specific | May acetylate N-terminal glutamate in specific tissues |
| NAT8B | N-terminal acetyltransferase 8B | Potential role in sperm function |
| NAT8L | N-acetyltransferase 8-like, involved in N-acetylaspartate synthesis | Metabolic enzyme with acetyltransferase domain |
| NAT9 | N-terminal acetyltransferase 9 | Poorly characterized, may target specific N-termini |
How Is protein-N-terminal-glutamate acetyltransferase activity Regulated?
The activity of protein-N-terminal-glutamate acetyltransferases is regulated at multiple levels. Transcriptionally, the expression of catalytic and auxiliary subunits is controlled by developmental and tissue-specific cues. Post-translationally, phosphorylation of subunits can modulate complex assembly and activity. Metabolically, the availability of acetyl-CoA, which is influenced by nutrient status and cellular energy levels, directly affects the rate of acetylation. Additionally, interaction with the ribosome and nascent polypeptide chains couples the activity to translation, ensuring co-translational modification. In response to stress, signaling pathways such as mTOR and the integrated stress response (ISR) can alter N-terminal acetylation patterns by regulating NAT expression or activity.
protein-N-terminal-glutamate acetyltransferase activity and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| NAA30 | Mitochondrial dysfunction, metabolic stress | NAA30 knockout cell lines and mouse models |
| NAA10 | Ogden syndrome, cancer | Patient-derived iPSCs and xenografts |
| NAA15 | Neurodevelopmental disorders | NAA15 knockout zebrafish and mouse |
| YY1 | Cardiac hypertrophy, metabolic reprogramming | Cardiomyocyte-specific knockout mice |
| HYPK | Huntington's disease, apoptosis | HYPK knockout neuronal cells |
Cancer
Dysregulation of N-terminal acetyltransferases, including those with glutamate specificity, has been observed in various cancers. For example, overexpression of NAA10 (NatA) is linked to tumor progression, while loss of NAA30 (NatC) can impair mitochondrial function and promote metabolic reprogramming. The activity defined by GO:1990190 may influence oncogenic signaling by modifying proteins involved in proliferation and apoptosis.
Developmental Disorders
Mutations in NAA10 and NAA15 cause Ogden syndrome and related neurodevelopmental disorders, characterized by intellectual disability and cardiac defects. Although glutamate-specific NATs are less directly implicated, the broader N-terminal acetylation machinery is essential for normal development, and defects in NatC subunits can lead to embryonic lethality in model organisms.
Cardiovascular and Metabolic Diseases
N-terminal acetylation is involved in cardiac metabolic reprogramming. The transcription factor YY1, which is regulated by acetylation, governs cardiac responses to exercise and pathological stress. Additionally, NAA30 knockout mice exhibit mitochondrial dysfunction, suggesting a role in metabolic homeostasis.
Neurodegeneration
HYPK, a modulator of N-terminal acetylation, interacts with huntingtin and is implicated in Huntington's disease pathology. Aberrant N-terminal acetylation may contribute to protein aggregation and neuronal toxicity, although direct links to glutamate-specific activity require further study.
From protein-N-terminal-glutamate acetyltransferase activity-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does NAA30 loss affect global N-terminal acetylation? | NAA30 knockout HEK293 cells followed by mass spectrometry |
| What is the substrate specificity of NAA60? | In vitro acetyltransferase assays with synthetic peptides |
| How does N-terminal glutamate acetylation affect protein stability? | Point mutation of N-terminal glutamate to alanine in reporter proteins |
| Can NAA60 be tagged for localization studies? | Knock-in of FLAG-tagged NAA60 in HeLa cells |
| Does overexpression of NAA30 alter mitochondrial function? | Doxycycline-inducible NAA30 overexpression in fibroblasts |
| What is the role of YY1 acetylation in cardiac stress? | YY1 knock-in mice with acetylation-deficient mutations |
How to Study the protein-N-terminal-glutamate acetyltransferase activity Process
| Method | What It Measures | Typical Application |
|---|---|---|
| In vitro acetyltransferase assay | Enzymatic activity and kinetics | Determining substrate specificity and catalytic efficiency |
| Mass spectrometry | N-terminal acetylation status and substrate identification | Global acetylome profiling in knockout cells |
| CRISPR knockout | Loss-of-function phenotypes | Studying gene essentiality and pathway crosstalk |
| CRISPR knock-in | Tagged protein localization and interactions | Live-cell imaging and immunoprecipitation |
| Site-directed mutagenesis | Effect of specific residues on activity | Mapping catalytic and substrate-binding sites |
| RNA-seq | Transcriptional changes upon NAT perturbation | Identifying downstream pathways |
| Co-immunoprecipitation | Protein-protein interactions | Discovering NAT complex components |
| Ribo-seq | Translation efficiency and co-translational modification | Linking N-terminal acetylation to translation |
In Vitro Acetyltransferase Assays
Recombinant NAT complexes or purified catalytic subunits can be incubated with synthetic peptides bearing N-terminal glutamate and acetyl-CoA. The reaction is monitored by detecting CoA release using thiol-reactive dyes or by mass spectrometry to confirm the acetylated product. These assays allow determination of kinetic parameters and substrate specificity.
Mass Spectrometry-Based Proteomics
Global N-terminal acetylome profiling using N-terminal peptide enrichment and LC-MS/MS can identify substrates of glutamate-specific NATs. Knockout or knockdown of candidate NATs followed by proteomic analysis reveals changes in N-terminal acetylation patterns. This approach is powerful for discovering novel substrates and understanding the scope of the activity.
CRISPR-Based Genetic Models
CRISPR-Cas9 can be used to generate knockout, point mutant, or knock-in cell lines and animal models to study the function of NAT genes. For example, knockout of NAA30 in cell lines followed by phenotypic assays can elucidate its role in mitochondrial function. Tagged knock-in of NAT subunits enables localization and interaction studies.
Structural Biology
X-ray crystallography and cryo-EM can provide atomic-level insights into how NAT complexes recognize N-terminal glutamate and catalyze acetyl transfer. Structures of NatC and NatF have revealed the molecular basis for substrate specificity. These studies inform the design of inhibitors or substrate mimetics.
How CRISPR Can Be Used to Study GO:1990190 protein-N-terminal-glutamate acetyltransferase activity
Knockout
CRISPR-Cas9 knockout of genes encoding glutamate-specific NATs (e.g., NAA30, NAA60) enables loss-of-function studies to assess their role in protein stability, localization, and cellular phenotypes. Knockout cell lines can be analyzed by mass spectrometry to identify substrates and by phenotypic assays to uncover pathways affected.
Point Mutation
Introducing point mutations in the catalytic domain of NATs (e.g., NAA30) via CRISPR can abolish enzymatic activity while preserving complex assembly, allowing separation of catalytic and scaffolding functions. Such models are valuable for dissecting the specific contribution of the acetyltransferase activity to biological processes.
Knock-in
Knock-in of epitope tags (e.g., FLAG, HA) or fluorescent proteins at the endogenous loci of NAT genes facilitates localization, interaction, and real-time activity studies. Tagged knock-in models avoid overexpression artifacts and provide physiological expression levels.
Overexpression
CRISPR activation (CRISPRa) or lentiviral overexpression of NAT genes can be used to study gain-of-function effects, such as increased N-terminal acetylation of specific substrates. Overexpression models are useful for identifying dose-dependent phenotypes and potential oncogenic roles.
How EDITGENE Supports protein-N-terminal-glutamate acetyltransferase activity Research
Researchers studying protein-N-terminal-glutamate acetyltransferase activity-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-based services to enable precise genetic manipulation and functional interrogation of these genes.
Contact EDITGENE today to design your custom CRISPR model for protein-N-terminal-glutamate acetyltransferase activity research.
Frequently Asked Questions About protein-N-terminal-glutamate acetyltransferase activity
What is GO:1990190?
GO:1990190 is a Gene Ontology molecular function term that describes protein-N-terminal-glutamate acetyltransferase activity, the enzyme activity that transfers an acetyl group from acetyl-CoA to the N-terminal glutamate of a peptide.
What genes are involved in protein-N-terminal-glutamate acetyltransferase activity?
Key genes include NAA30, NAA35, NAA38 (NatC complex), and NAA60 (NatF), which encode subunits of N-terminal acetyltransferases that can acetylate N-terminal glutamate.
What is the reaction catalyzed by protein-N-terminal-glutamate acetyltransferase?
The enzyme catalyzes: acetyl-CoA + N-terminal L-glutamate in peptide = CoA + N-acetyl-L-glutamate-peptide.
How is protein-N-terminal-glutamate acetyltransferase activity regulated?
It is regulated by expression levels of NAT subunits, acetyl-CoA availability, phosphorylation, and interaction with the ribosome.
What diseases are associated with defects in N-terminal acetylation?
Defects have been linked to cancer, developmental disorders like Ogden syndrome, cardiovascular disease, and neurodegeneration.
What methods are used to study protein-N-terminal-glutamate acetyltransferase activity?
Common methods include in vitro acetyltransferase assays, mass spectrometry, CRISPR knockout/knock-in models, and structural biology.
Can CRISPR be used to study N-terminal acetyltransferases?
Yes, CRISPR-Cas9 can generate knockout, point mutant, knock-in, and overexpression models to dissect gene function.
What is the difference between N-terminal acetylation and lysine acetylation?
N-terminal acetylation occurs on the alpha-amino group of the first residue and is often irreversible, while lysine acetylation occurs on internal lysine side chains and is reversible.
Which N-terminal acetyltransferase is specific for glutamate?
NatF (NAA60) in higher eukaryotes and NatC (NAA30/NAA35/NAA38) can acetylate N-terminal glutamate, with NatF being particularly specific.
How does N-terminal glutamate acetylation affect protein function?
It can alter protein stability, subcellular localization, and interactions, often by creating or destroying degrons or changing charge.
Conclusion
GO:1990190, protein-N-terminal-glutamate acetyltransferase activity, represents a specific and biologically significant enzymatic function within the broader N-terminal acetylation machinery. It influences protein fate and cellular processes, with implications for development, metabolism, and disease. Understanding this activity requires integrating genetic, biochemical, and proteomic approaches, and CRISPR-based models are invaluable for dissecting its roles. EDITGENE offers comprehensive services to support such research, from knockout and knock-in models to library screening and bioinformatics.
References
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- 2. Morizono H et al.. 2004. Mammalian N-acetylglutamate synthase.. Mol Genet Metab 81 Suppl 1(Suppl 1):S4-11 PMID: 15050968
- 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
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