GO:0031996 thioesterase binding: Mechanism, Genes and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0031996 thioesterase binding is a molecular function defined as binding to a thioesterase, also known as thiolesterase binding.
• Thioesterases are enzymes that hydrolyze thioester bonds, and their binding partners regulate processes such as protein depalmitoylation and natural product biosynthesis [1,2,5].
• Key proteins involved include palmitoyl-protein thioesterase 1 (PPT1), which is bound by hydroxychloroquine and chloroquine dimers, and penicillin-binding protein-type thioesterases (PBP-type TEs) such as PenA and FlkO [6,8,2].
• Thioesterase binding is relevant to human diseases including neurodegeneration, osteoarthritis, and cancer, and to biotechnological applications like chemo-enzymatic synthesis of macrolactams [1,7,4].
• Research methods to study thioesterase binding include computational docking, biochemical assays, structural biology, and CRISPR-based gene editing [6,5].
• EDITGENE provides CRISPR services including knockout, point mutation, knock-in, overexpression, library screening, and bioinformatics to study thioesterase binding-related genes.
Description
Thioesterase binding (GO:0031996) is a molecular function that describes the binding of a protein or small molecule to a thioesterase enzyme. Thioesterases catalyze the cleavage of thioester bonds, a reaction critical for various biological processes including fatty acid metabolism, protein palmitoylation cycles, and the biosynthesis of natural products [1,2]. The binding event can modulate thioesterase activity, target the enzyme to specific substrates, or serve as a mechanism for drug action, as seen with antimalarial drugs binding to palmitoyl-protein thioesterase 1 (PPT1). Understanding thioesterase binding is therefore essential for dissecting both normal physiology and disease mechanisms. Recent studies have highlighted the role of thioesterase binding in diverse contexts, from the regulation of protein depalmitoylation, a process reversed by thioesterases such as PPT1 and APT1, to the cyclization of peptides by penicillin-binding protein-type thioesterases in bacteria [2,5]. These interactions are not only fundamental to cellular homeostasis but also represent potential therapeutic targets. For example, computational studies have shown that hydroxychloroquine and chloroquine dimers bind to PPT1 and its glycosylated forms, suggesting a mechanism for drug-induced retinopathy or autophagy modulation. In osteoarthritis research, thioesterase binding may influence lipid metabolism and inflammation, though direct evidence is still emerging. This article provides a comprehensive overview of thioesterase binding, covering its definition, key genes, molecular mechanisms, disease relevance, and research methodologies, with a focus on how CRISPR-based models can accelerate discovery.
thioesterase binding At A Glance
| GO ID | GO:0031996 |
|---|---|
| GO term | thioesterase binding |
| Ontology | molecular_function |
| Synonym | thiolesterase binding |
| Major function | Binding to a thioesterase enzyme, potentially regulating its activity or mediating drug action |
| Related enzymes | Palmitoyl-protein thioesterase 1 (PPT1), acyl-protein thioesterase 1 (APT1), penicillin-binding protein-type thioesterases (PenA, FlkO) |
| Disease relevance | Neurodegeneration, osteoarthritis, cancer, and drug-induced retinopathy |
| Research methods | Computational docking, biochemical binding assays, structural biology, CRISPR screens |
What Is GO:0031996?
Thioesterase binding (GO:0031996) is the molecular function of selectively interacting with a thioesterase enzyme. A thioesterase is any enzyme that catalyzes the hydrolysis of a thioester bond, releasing a thiol and a carboxylate. The binding can occur between a protein and a thioesterase (protein-protein interaction) or between a small molecule and a thioesterase. This function is distinct from the catalytic activity of the thioesterase itself; it describes the binding event that may regulate the enzyme's activity, localization, or substrate specificity. The synonym thiolesterase binding is also used.
Why Is thioesterase binding Important in Cell Biology?
Thioesterase binding is important because it regulates fundamental cellular processes such as protein depalmitoylation, which controls protein localization and signaling. Dysregulation of thioesterase binding can lead to diseases including neurodegenerative disorders, where mutations in PPT1 cause infantile neuronal ceroid lipofuscinosis. In osteoarthritis, lipid metabolism and inflammation may be influenced by thioesterase interactions, though direct evidence is limited. Furthermore, thioesterase binding is exploited in biotechnology for the chemo-enzymatic synthesis of complex macrolactams, and in pharmacology, as drugs like chloroquine bind to PPT1 [6,4]. Thus, understanding thioesterase binding offers insights into both basic biology and therapeutic development.
• Regulates protein depalmitoylation, a reversible lipid modification critical for protein trafficking and signaling.
• Mediates the action of antimalarial drugs such as hydroxychloroquine and chloroquine, which bind to PPT1.
• Involved in the biosynthesis of natural products, including macrolactams, through penicillin-binding protein-type thioesterases [2,5].
• Potential role in osteoarthritis pathogenesis via lipid metabolism and inflammation.
• Implicated in cancer through altered palmitoylation cycles and thioesterase expression.
• Enables chemo-enzymatic synthesis of cyclic peptides and macrolactams for drug discovery.
• Provides a target for CRISPR-based functional studies to dissect gene-disease links.
• Facilitates the development of small-molecule modulators of thioesterase activity.
• Contributes to our understanding of lysosomal proteostasis and implantation biology.
• Offers a paradigm for studying enzyme-ligand interactions in precision medicine.
Molecular Mechanism of thioesterase binding
Substrate recognition and binding specificity
In simple terms: Thioesterases bind to specific substrates or partner proteins through shape and chemical complementarity.
Thioesterase binding typically involves the recognition of a thioesterase by a partner protein or small molecule. For example, penicillin-binding protein-type thioesterases (PBP-type TEs) such as PenA and FlkO recognize peptide substrates with specific leader sequences, facilitating cyclization [8,2]. The binding specificity is determined by the active site architecture and surrounding loops. In the case of PPT1, computational studies have shown that hydroxychloroquine and chloroquine dimers bind to the enzyme's active site and glycosylated forms, suggesting that glycosylation may modulate binding affinity. These interactions often involve hydrophobic and electrostatic contacts that stabilize the complex.
Catalytic mechanism and regulation of activity
In simple terms: Binding can turn the thioesterase on or off, or change what it does.
Binding to a thioesterase can regulate its catalytic activity. For instance, palmitoyl-protein thioesterase 1 (PPT1) hydrolyzes thioester bonds in palmitoylated proteins, and its binding to drugs like chloroquine may inhibit this activity, leading to altered autophagy and lysosomal function [6,1]. In bacterial PBP-type TEs, binding to a substrate peptide positions the thioester bond for nucleophilic attack by the catalytic serine, resulting in macrolactam formation. The regulation of thioesterase binding can also occur through post-translational modifications, such as glycosylation of PPT1, which affects its interaction with ligands.
Structural features of thioesterase binding interfaces
In simple terms: The 3D shape of the thioesterase determines what it can bind.
Structural studies of PBP-type thioesterases have revealed a conserved alpha/beta hydrolase fold with a catalytic triad (Ser-His-Asp) and an oxyanion hole [8,4]. The binding interface often includes a hydrophobic pocket that accommodates the acyl chain of the substrate. For PPT1, the enzyme is a palmitoyl-protein thioesterase with a catalytic triad and N-glycosylation sites; glycosylation can alter the surface topology and thus binding to small molecules. These structural insights are critical for designing inhibitors or modulators of thioesterase binding.
Cofactors and post-translational modifications
In simple terms: Other molecules can attach to the thioesterase and change its binding properties.
Thioesterase binding can be influenced by cofactors and post-translational modifications. For example, PPT1 is glycosylated, and its glycosylated forms exhibit differential binding to hydroxychloroquine and chloroquine dimers. In PBP-type thioesterases, no specific cofactors are required for catalysis, but the presence of a leader peptide in the substrate is essential for efficient binding and cyclization. Additionally, palmitoylation itself can regulate the localization of thioesterases, thereby affecting their availability for binding partners.
Biological outcomes of thioesterase binding
In simple terms: When something binds to a thioesterase, it can change how cells work.
The binding of proteins or small molecules to thioesterases can have diverse biological outcomes. In protein depalmitoylation, the binding of acyl-protein thioesterases (APTs) to their substrates reverses palmitoylation, affecting protein trafficking and signaling. In natural product biosynthesis, the binding of PBP-type thioesterases to peptide substrates leads to macrocyclization, producing bioactive compounds [2,5]. In disease, drug binding to PPT1 can disrupt lysosomal function, as seen with chloroquine-induced retinopathy. These outcomes highlight the functional significance of thioesterase binding in health and disease.
Key Genes Involved in GO:0031996 thioesterase binding
The following genes encode proteins that are either thioesterases or known binding partners, and are central to research on GO:0031996.
| Gene | Major Role | Research Relevance |
|---|---|---|
| PPT1 | Palmitoyl-protein thioesterase 1; hydrolyzes palmitate from proteins | Target of chloroquine; mutations cause neuronal ceroid lipofuscinosis [1,6] |
| APT1 (LYPLA1) | Acyl-protein thioesterase 1; depalmitoylates proteins | Regulates protein trafficking and signaling |
| APT2 (LYPLA2) | Acyl-protein thioesterase 2; depalmitoylates proteins | Potential role in cancer and neurodegeneration |
| PenA | Penicillin-binding protein-type thioesterase from Streptomyces | Cyclizes small peptides; model for thioesterase binding |
| FlkO | PBP-type thioesterase in cyclofaulknamycin biosynthesis | Involved in macrolactam formation |
| PPT2 | Palmitoyl-protein thioesterase 2 | Related to PPT1 but less studied |
| LYPLAL1 | Lysophospholipase-like 1; putative thioesterase | Associated with metabolic traits |
| ABHD17A | Alpha/beta hydrolase domain-containing protein 17A; depalmitoylase | Regulates synaptic function |
| ABHD17B | Alpha/beta hydrolase domain-containing protein 17B; depalmitoylase | Potential role in cancer |
| ABHD17C | Alpha/beta hydrolase domain-containing protein 17C; depalmitoylase | Modulates protein palmitoylation |
| PPT1 (glycosylated) | Glycosylated form of PPT1 | Binds chloroquine dimers with altered affinity |
| PBP-type TE (general) | Penicillin-binding protein-type thioesterases | Biocatalysts for macrocyclization [4,5] |
| Serine hydrolase-like | Putative thioesterases with alpha/beta hydrolase fold | Potential binding partners in bacteria |
| Thioesterase domain of FAS | Fatty acid synthase thioesterase domain | Releases fatty acids; target for inhibitors |
| Thioesterase II (TEII) | Type II thioesterase in polyketide synthases | Editing of polyketide biosynthesis |
| Palmitoyl transferase (DHHC) | Palmitoyl acyltransferases; opposite of thioesterases | Regulate palmitoylation cycle |
| Lysosomal enzyme (e.g., PPT1) | Lysosomal thioesterase | Involved in autophagy and proteostasis |
How Is thioesterase binding Regulated?
Thioesterase binding is regulated at multiple levels. The expression and activity of thioesterases such as PPT1 and APT1 are controlled by transcription factors and post-translational modifications. Glycosylation of PPT1 affects its binding to drugs and possibly endogenous ligands. In bacteria, the availability of substrate peptides and the presence of leader sequences regulate the binding of PBP-type thioesterases. Additionally, palmitoylation cycles themselves create a dynamic equilibrium where thioesterase binding is modulated by the opposing action of palmitoyl transferases. In the context of lysosomal proteostasis, thioesterase activity may be influenced by autophagy pathways.
thioesterase binding and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| PPT1 | Neuronal ceroid lipofuscinosis; lysosomal dysfunction | PPT1 knockout mice; patient-derived iPSCs |
| APT1 (LYPLA1) | Cancer; Ras signaling | APT1 knockout cancer cell lines; xenografts |
| PenA | Bacterial natural product biosynthesis | Recombinant E. coli expressing PenA; in vitro cyclization assays |
| FlkO | Cyclofaulknamycin biosynthesis | Streptomyces knockout; heterologous expression |
| ABHD17A | Synaptic function; neurodegeneration | ABHD17A knockout neurons; behavioral studies |
Neurodegeneration and lysosomal storage disorders
Mutations in PPT1 cause infantile neuronal ceroid lipofuscinosis, a fatal neurodegenerative disease characterized by lysosomal accumulation of lipofuscin. The binding of PPT1 to its substrates is essential for normal lysosomal function, and disruption leads to neuronal death. Additionally, drug binding to PPT1, such as chloroquine, can exacerbate lysosomal dysfunction and retinopathy. Understanding thioesterase binding in this context may inform therapeutic strategies for neurodegenerative disorders.
Osteoarthritis and inflammatory joint disease
Osteoarthritis is a degenerative joint disease with a complex etiology involving inflammation and lipid metabolism. While direct evidence for thioesterase binding in osteoarthritis is limited, palmitoylation and depalmitoylation cycles are known to regulate inflammatory signaling pathways. Thioesterases such as APT1 may modulate the activity of proteins involved in cartilage degradation. Further research is needed to establish a causal link.
Cancer and cell signaling
Altered protein palmitoylation is increasingly recognized in cancer, where thioesterases like APT1 can act as tumor suppressors or oncogenes depending on context. Binding of regulatory proteins to thioesterases may influence cancer cell proliferation and metastasis. For example, inhibition of APT1 has been shown to affect Ras signaling. Targeting thioesterase binding interfaces could offer new therapeutic avenues.
Infectious disease and drug action
Thioesterase binding is exploited by antimalarial drugs such as chloroquine, which bind to PPT1 and other thioesterases, disrupting lysosomal function in parasites. In bacteria, PBP-type thioesterases are involved in the biosynthesis of antibiotics and virulence factors, and their binding to substrates is a potential target for new antimicrobials [2,5]. Understanding these interactions can guide drug design.
From thioesterase binding-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does loss of PPT1 affect lysosomal function? | PPT1 knockout cell line (e.g., HEK293) or mouse model |
| How does a point mutation in the catalytic serine of PenA affect substrate binding? | Point mutation (S-to-A) knock-in in PenA-expressing bacteria |
| Can we tag endogenous APT1 to study its interactome? | Knock-in of FLAG or GFP tag at APT1 locus in mammalian cells |
| What is the effect of PPT1 overexpression on drug sensitivity? | Overexpression of PPT1 in cancer cell lines |
| Which genes regulate thioesterase binding in osteoarthritis? | CRISPR library screening in chondrocytes |
| Does glycosylation of PPT1 alter chloroquine binding? | Knock-in of glycosylation site mutations in PPT1 |
How to Study the thioesterase binding Process
| Method | What It Measures | Typical Application |
|---|---|---|
| Molecular docking | Predicted binding pose and affinity | Virtual screening of drugs against PPT1 |
| Isothermal titration calorimetry | Binding affinity (Kd) and thermodynamics | Characterizing thioesterase-peptide interactions |
| X-ray crystallography | 3D structure of thioesterase-ligand complex | Understanding catalytic mechanism |
| CRISPR knockout | Loss-of-function phenotype | Studying PPT1 in lysosomal function |
| CRISPR knock-in | Tagged protein expression | Interactome analysis of APT1 |
| CRISPR overexpression | Gain-of-function phenotype | Assessing drug sensitivity |
| CRISPR library screening | Identification of modifier genes | Discovering regulators of thioesterase binding |
| Proteomics | Protein-protein interactions | Mapping thioesterase interactome |
Computational docking and molecular dynamics
Computational approaches such as molecular docking and molecular dynamics simulations are used to predict and analyze the binding of small molecules or proteins to thioesterases. For example, Vergoten et al. used computational methods to study the binding of hydroxychloroquine and chloroquine dimers to PPT1 and its glycosylated forms. These techniques provide atomic-level insights into binding affinity and pose, guiding experimental validation.
Biochemical binding assays
Biochemical assays such as isothermal titration calorimetry (ITC), surface plasmon resonance (SPR), and fluorescence polarization can measure the binding affinity between thioesterases and their partners. For PBP-type thioesterases, in vitro cyclization assays with synthetic peptides can assess substrate binding and catalytic efficiency [5,8]. These methods are essential for quantifying interactions and screening inhibitors.
Structural biology (X-ray crystallography, cryo-EM)
Structural biology techniques, including X-ray crystallography and cryo-electron microscopy, provide high-resolution structures of thioesterase-ligand complexes. Structures of PBP-type thioesterases have revealed the active site architecture and substrate binding pockets [8,4]. Such structures are invaluable for rational drug design and understanding binding mechanisms.
CRISPR-based functional genomics
CRISPR knockout, knock-in, and overexpression models enable functional studies of thioesterase binding in cells. For example, knocking out PPT1 can reveal its role in lysosomal function, while knock-in of tagged versions allows interactome profiling. CRISPR library screening can identify genes that modulate thioesterase binding under specific conditions, such as in osteoarthritis.
How CRISPR Can Be Used to Study GO:0031996 thioesterase binding
Knockout
CRISPR knockout of thioesterase genes such as PPT1 or APT1 allows researchers to study loss-of-function phenotypes. For example, PPT1 knockout cells exhibit lysosomal accumulation and impaired autophagy, mimicking aspects of neuronal ceroid lipofuscinosis. Knockout models are essential for validating the role of thioesterase binding in disease pathways.
Point Mutation
Point mutations can be introduced into thioesterase genes to dissect catalytic residues or binding interfaces. For instance, mutating the catalytic serine of PenA to alanine abolishes its cyclization activity, confirming its role in substrate binding and catalysis. Such models help distinguish between binding and catalytic functions.
Knock-in
Knock-in of tags (e.g., FLAG, GFP) or disease-associated mutations allows for tracking and functional analysis of thioesterases in their native context. For example, knocking in a glycosylation site mutation in PPT1 can reveal how glycosylation affects drug binding. Knock-in models are also used to create reporter cell lines for high-throughput screening.
Overexpression
Overexpression of thioesterases or their binding partners can be achieved via CRISPR activation (CRISPRa) or lentiviral delivery. Overexpressing PPT1 in cancer cells can increase sensitivity to chloroquine, providing insights into drug response. Overexpression models are useful for gain-of-function studies and for producing recombinant proteins for structural studies.
How EDITGENE Supports thioesterase binding Research
Researchers studying thioesterase binding-related genes often need to determine whether a candidate gene is causally involved in a specific biological process or disease. This requires precise genetic manipulation, which can be achieved through CRISPR-based genome editing. EDITGENE offers a comprehensive suite of services to support such investigations, from knockout to knock-in and library screening.
Contact EDITGENE today to design your custom CRISPR model for thioesterase binding research.
Frequently Asked Questions About thioesterase binding
What is thioesterase binding?
Thioesterase binding (GO:0031996) is the molecular function of binding to a thioesterase enzyme, which can regulate its activity or mediate drug action.
What genes are involved in thioesterase binding?
Key genes include PPT1, APT1 (LYPLA1), APT2 (LYPLA2), PenA, FlkO, and ABHD17 family members [1,2,8].
What diseases are associated with thioesterase binding?
Diseases include neuronal ceroid lipofuscinosis, osteoarthritis, cancer, and infectious diseases [1,6,7].
How is thioesterase binding studied?
Methods include computational docking, biochemical assays, structural biology, and CRISPR-based functional genomics [6,5,8].
What is the role of PPT1 in thioesterase binding?
PPT1 is a palmitoyl-protein thioesterase that binds drugs like chloroquine; mutations cause neurodegeneration [1,6].
Can CRISPR be used to study thioesterase binding?
Yes, CRISPR knockout, knock-in, and overexpression models enable functional studies of thioesterase genes.
What are penicillin-binding protein-type thioesterases?
They are bacterial enzymes that cyclize peptides, and their binding to substrates is studied for natural product biosynthesis [2,5].
How does chloroquine interact with thioesterases?
Chloroquine dimers bind to PPT1 and its glycosylated forms, potentially inhibiting its activity.
What is the relationship between thioesterase binding and osteoarthritis?
Thioesterase binding may influence lipid metabolism and inflammation in osteoarthritis, though direct evidence is limited.
What services does EDITGENE offer for thioesterase binding research?
EDITGENE provides CRISPR knockout, point mutation, knock-in, overexpression, library screening, and bioinformatics services.
Conclusion
Thioesterase binding (GO:0031996) is a fundamental molecular function with broad implications in cell biology, disease, and biotechnology. From regulating protein depalmitoylation to enabling natural product synthesis, the interactions between thioesterases and their binding partners are critical for cellular homeostasis. Dysregulation of these interactions contributes to neurodegeneration, cancer, and other diseases, making them attractive therapeutic targets. Advances in CRISPR-based genome editing and computational modeling are accelerating our understanding of thioesterase binding. EDITGENE's comprehensive services empower researchers to dissect these interactions with precision, paving the way for novel diagnostics and therapeutics.
References
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- 3. Wang P et al.. 2024. The presence of blastocyst within the uteri facilitates lumenal epithelium transformation for implantation via upregulating lysosome proteostasis activity.. Autophagy 20(1):58-75 PMID: 37584546
- 4. Kobayashi M et al.. 2023. Chemo-Enzymatic Synthesis of Non-ribosomal Macrolactams by a Penicillin-Binding Protein-Type Thioesterase.. Methods Mol Biol 2670:127-144 PMID: 37184702
- 5. Budimir ZL et al.. 2024. Biocatalytic cyclization of small macrolactams by a penicillin-binding protein-type thioesterase.. Nat Chem Biol 20(1):120-128 PMID: 38062262
- 6. Vergoten G et al.. 2022. Binding of hydroxychloroquine and chloroquine dimers to palmitoyl-protein thioesterase 1 (PPT1) and its glycosylated forms: a computational approach.. J Biomol Struct Dyn 40(18):8197-8205 PMID: 33876698
- 7. Han S. 2022. Osteoarthritis year in review 2022: biology.. Osteoarthritis Cartilage 30(12):1575-1582 PMID: 36150676
- 8. Matsuda K et al.. 2021. PenA, a penicillin-binding protein-type thioesterase specialized for small peptide cyclization.. J Ind Microbiol Biotechnol 48(3-4) PMID: 33713128
