GO:1904570 negative regulation of selenocysteine incorporation: Selenoprotein Synthesis Control, Genes, Functions and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:1904570 describes any process that stops, prevents or reduces the frequency, rate or extent of selenocysteine incorporation into proteins.
• Selenocysteine incorporation is a specialized translation event requiring the UGA codon to be recoded as selenocysteine rather than termination.
• Negative regulation of this process can occur through limiting selenium supply, altering selenophosphate synthetase activity, or changing the availability of the selenocysteine tRNA.
• Selenoprotein P and selenocysteine lyase are key regulators of selenium distribution and recycling that influence selenocysteine incorporation.
• Dysregulation of selenocysteine incorporation is linked to thyroid hormone metabolism, male fertility, endothelial activation, and oxidative stress-related diseases [1,4,5].
• CRISPR knockout, point mutation, knock-in, and overexpression models are essential to dissect the causal roles of genes controlling selenocysteine incorporation [3,8].
Description
Selenocysteine incorporation is a unique co-translational process in which the UGA codon, normally a stop signal, is recoded to insert the amino acid selenocysteine into a growing polypeptide chain. This process is essential for the synthesis of selenoproteins, a family of enzymes that includes glutathione peroxidases, thioredoxin reductases, and iodothyronine deiodinases, which protect cells from oxidative damage and regulate thyroid hormone metabolism. The Gene Ontology term GO:1904570, negative regulation of selenocysteine incorporation, captures the biological processes that reduce the frequency, rate, or extent of this recoding event. Understanding this negative regulation is critical because insufficient selenocysteine incorporation can impair antioxidant defense and endocrine function, while excessive suppression may contribute to disease pathology [1,4,5]. Research into GO:1904570 has revealed that selenium availability, the selenocysteine lyase pathway, and the selenophosphate synthetase reaction are central nodes of control [2,3]. For example, selenoprotein P and selenocysteine lyase work together to maintain selenium homeostasis, and their interplay directly affects how much selenocysteine can be incorporated into nascent selenoproteins. In Trypanosomatids, the structure and function of selenophosphate synthetase and its interaction with selenocysteine lyase provide a model for understanding how these enzymes regulate selenocysteine production. Additionally, dominant-negative mutations in glutathione peroxidase 4 (GPX4) can reduce selenoprotein activity, illustrating how negative regulation at the protein level impacts fertility and cellular redox balance. This article synthesizes authoritative QuickGO data and verified PubMed literature to provide a research-grade overview of GO:1904570. We cover the definition, biological importance, molecular mechanisms, key genes, disease associations, and state-of-the-art CRISPR-based methods for studying negative regulation of selenocysteine incorporation. By focusing on real experimental evidence, we aim to support researchers designing experiments to manipulate this pathway in cell models and animal systems [1,2,3,4,5,7,8].
negative regulation of selenocysteine incorporation At A Glance
| GO ID | GO:1904570 |
|---|---|
| GO term | negative regulation of selenocysteine incorporation |
| Ontology | biological_process |
| Synonym | down regulation of selenocysteine incorporation, down-regulation of selenocysteine incorporation, downregulation of selenocysteine incorporation, inhibition of selenocysteine incorporation |
| Major function | Reduces the frequency, rate or extent of selenocysteine incorporation into proteins |
| Related process | Selenocysteine incorporation (GO:0001514) and its positive regulation |
| Key enzymes | Selenophosphate synthetase, selenocysteine lyase, selenoprotein P |
| Cellular context | Cytoplasm, nucleus, and mitochondria where selenoprotein translation occurs |
| Disease relevance | Thyroid disorders, male infertility, endothelial dysfunction, oxidative stress-related diseases |
What Is GO:1904570?
GO:1904570, negative regulation of selenocysteine incorporation, is defined as any process that stops, prevents or reduces the frequency, rate or extent of selenocysteine incorporation. In practical terms, it encompasses molecular events that decrease the efficiency with which the UGA codon is recoded to selenocysteine during translation of selenoprotein mRNAs. This negative regulation can be achieved by limiting the supply of selenium, reducing the activity of selenophosphate synthetase, altering the availability of the specialized tRNA for selenocysteine, or changing the expression of selenoprotein P and selenocysteine lyase [2,3].
Why Is negative regulation of selenocysteine incorporation Important in Cell Biology?
Negative regulation of selenocysteine incorporation is important because it directly controls the cellular capacity to synthesize selenoproteins, which are essential for antioxidant defense, thyroid hormone activation, and redox signaling. When this process is dysregulated, cells may suffer from impaired oxidative stress responses, leading to endothelial activation, male infertility, and metabolic imbalances [4,5]. Understanding how this negative regulation works at the molecular level can reveal therapeutic targets for diseases linked to selenium metabolism and selenoprotein dysfunction [1,2].
• Controls the synthesis of selenoproteins, which protect cells from oxidative damage.
• Regulates thyroid hormone metabolism by affecting deiodinase selenoproteins.
• Influences male fertility through glutathione peroxidase 4 (GPX4) activity.
• Modulates endothelial cell activation by suppressing glutathione peroxidase 1 (GPX1) protein expression.
• Affects selenium distribution and recycling via selenoprotein P and selenocysteine lyase.
• Provides a mechanism for cellular adaptation to selenium deficiency.
• Is a potential target for cancer therapy due to selenoprotein roles in redox balance.
• Can be studied using CRISPR knockout and point mutation models to dissect gene function [3,8].
• Impacts translation readthrough mechanisms that compete with termination at UGA codons.
• Relevant to bacterial systems where SelB regulates selenocysteine incorporation.
What Happens During negative regulation of selenocysteine incorporation?
Selenium Availability and Selenoprotein P
In simple terms: When selenium is scarce, cells reduce selenocysteine incorporation to conserve this essential trace element.
Selenoprotein P (SELENOP) is a major selenium transport protein that delivers selenium to tissues for selenoprotein synthesis. Negative regulation of selenocysteine incorporation can occur when selenium supply is limited, leading to reduced charging of the selenocysteine tRNA and decreased recoding of UGA codons. Selenocysteine lyase (SCLY) interacts with selenoprotein P to recycle selenium from degraded selenoproteins, and its activity can modulate the pool of selenium available for new selenocysteine incorporation. In Trypanosomatids, selenophosphate synthetase (SPS) interacts with selenocysteine lyase, and this interaction is critical for regulating selenophosphate production, a key selenium donor for selenocysteine synthesis.
Selenophosphate Synthetase and tRNA Charging
In simple terms: The enzyme selenophosphate synthetase makes the active form of selenium that gets attached to the special tRNA for selenocysteine.
Selenophosphate synthetase (SPS) catalyzes the synthesis of selenophosphate, which is the selenium donor for the conversion of seryl-tRNA to selenocysteinyl-tRNA. Negative regulation of selenocysteine incorporation can be achieved by reducing SPS activity or expression, thereby limiting the amount of selenophosphate available for tRNA charging. Structural and functional studies of Trypanosomatid SPS have shown that its interaction with selenocysteine lyase is essential for efficient selenium utilization, and disruption of this interaction reduces selenocysteine incorporation.
Competition with Translation Termination
In simple terms: At the UGA codon, the cell must choose between stopping protein synthesis and inserting selenocysteine; negative regulation tips the balance toward stopping.
Aminoglycoside antibiotics can promote translation readthrough at premature stop codons through a non-stochastic mechanism that competes with translation termination. This principle applies to selenocysteine incorporation, where the UGA codon must be recoded. Negative regulation of selenocysteine incorporation can occur when termination factors outcompete the selenocysteine insertion machinery, leading to premature termination and reduced selenoprotein synthesis. In Escherichia coli, the SelB elongation factor is required for selenocysteine incorporation, and its availability or activity can be negatively regulated to reduce incorporation.
Dominant-Negative Effects of Mutant Selenoproteins
In simple terms: A mutant selenoprotein can interfere with the function of normal selenoproteins, effectively reducing selenocysteine incorporation outcomes.
Expression of a catalytically inactive mutant form of glutathione peroxidase 4 (GPX4) confers a dominant-negative effect in male fertility, demonstrating that mutant selenoproteins can suppress the functional output of selenocysteine incorporation. This dominant-negative mechanism reduces the overall selenoprotein activity even when wild-type GPX4 is present, effectively acting as a negative regulation of selenocysteine incorporation at the protein level. Similarly, inhibition of cellular methyltransferases promotes endothelial cell activation by suppressing glutathione peroxidase 1 (GPX1) protein expression, providing another example of negative regulation of selenoprotein synthesis.
Selenium Determination and Metabolic Feedback
In simple terms: Measuring selenium levels helps researchers understand how much selenocysteine incorporation can occur.
Spectrophotometric determination of selenium through triiodide anion provides a method to quantify selenium status, which directly impacts selenocysteine incorporation. When selenium levels are low, negative regulation of selenocysteine incorporation is triggered to conserve selenium for essential functions. This feedback mechanism ensures that selenoprotein synthesis is tightly controlled according to selenium availability.
Key Genes Involved in GO:1904570 negative regulation of selenocysteine incorporation
The following genes and proteins are central to the negative regulation of selenocysteine incorporation, based on verified literature.
| Gene | Major Role | Research Relevance |
|---|---|---|
| SELENOP | Selenium transport protein; delivers selenium for selenoprotein synthesis | Knockout models show impaired selenium distribution and reduced selenocysteine incorporation |
| SCLY | Selenocysteine lyase; recycles selenium from degraded selenoproteins | Interacts with SELENOP and SPS to regulate selenium pool [2,3] |
| SPS1/2 | Selenophosphate synthetase; produces selenophosphate for tRNA charging | Structural studies reveal interaction with SCLY; target for negative regulation |
| GPX4 | Glutathione peroxidase 4; selenoprotein protecting against lipid peroxidation | Dominant-negative mutant reduces fertility; model for negative regulation |
| GPX1 | Glutathione peroxidase 1; major antioxidant selenoprotein | Methyltransferase inhibition suppresses GPX1 protein expression |
| SelB | Bacterial elongation factor for selenocysteine incorporation | Required for incorporation; its regulation affects cytotoxic necrotizing factor 1 expression |
| SEPHS1 | Selenophosphate synthetase 1 in humans | Potential target for modulating selenocysteine incorporation |
| SEPHS2 | Selenophosphate synthetase 2 in humans | May regulate selenophosphate supply |
| EEFSEC | Eukaryotic elongation factor for selenocysteine incorporation | Essential for recoding UGA as selenocysteine |
| SECISBP2 | SECIS-binding protein 2; recruits selenocysteine machinery to mRNA | Mutations cause selenoprotein deficiency |
| TRU-TCA1-1 | Selenocysteine tRNA | Charged with selenocysteine; availability affects incorporation rate |
| PSTK | Phosphoseryl-tRNA kinase; phosphorylates seryl-tRNA for selenocysteine synthesis | Required for selenocysteine tRNA maturation |
| SEPSECS | Selenocysteine synthase; converts phosphoseryl-tRNA to selenocysteinyl-tRNA | Key enzyme in selenocysteine biosynthesis |
| GPX2 | Glutathione peroxidase 2; gastrointestinal selenoprotein | May be affected by negative regulation of selenocysteine incorporation |
| TXNRD1 | Thioredoxin reductase 1; selenoprotein involved in redox regulation | Sensitive to selenium availability |
| DIO1 | Iodothyronine deiodinase 1; selenoprotein for thyroid hormone activation | Negative regulation impacts thyroid hormone metabolism |
| DIO2 | Iodothyronine deiodinase 2; selenoprotein for thyroid hormone activation | Affected by selenium status |
| DIO3 | Iodothyronine deiodinase 3; selenoprotein for thyroid hormone inactivation | Regulated by selenium availability |
How Is negative regulation of selenocysteine incorporation Regulated?
Negative regulation of selenocysteine incorporation is controlled at multiple levels. Selenium availability is a primary regulator: when selenium is scarce, the cell reduces selenocysteine incorporation to conserve this trace element. Selenoprotein P and selenocysteine lyase act as sensors and effectors of selenium distribution, with their interaction determining how much selenium is directed to selenophosphate synthesis. Selenophosphate synthetase activity is also regulated by its interaction with selenocysteine lyase, as shown in Trypanosomatids. Additionally, translation termination factors compete with the selenocysteine insertion machinery at UGA codons, and conditions that favor termination reduce incorporation. In bacteria, the availability of SelB elongation factor is a key determinant of selenocysteine incorporation efficiency.
negative regulation of selenocysteine incorporation and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| GPX4 | Male infertility; oxidative stress | Knockout and point mutation models in mice |
| GPX1 | Endothelial dysfunction; cardiovascular disease | Knockdown and overexpression in endothelial cells |
| SELENOP | Selenium deficiency; thyroid disorders | Knockout mice and cell lines |
| SCLY | Selenium metabolism disorders | Knockout and knock-in models [2,3] |
| SEPHS1 | Impaired selenophosphate synthesis | CRISPR knockout in cell lines |
Thyroid Hormone Disorders
Selenium is essential for thyroid hormone synthesis and metabolism, and selenoproteins such as iodothyronine deiodinases require selenocysteine incorporation for their activity. Negative regulation of selenocysteine incorporation can impair thyroid hormone activation, contributing to hypothyroidism and related metabolic disorders. The interplay between selenium, iodine, and iron is critical for thyroid function, and disruption of selenocysteine incorporation may exacerbate thyroid pathology.
Male Infertility
Glutathione peroxidase 4 (GPX4) is a selenoprotein essential for sperm function and male fertility. Expression of a catalytically inactive mutant GPX4 confers a dominant-negative effect, reducing fertility and demonstrating that negative regulation of selenocysteine incorporation can directly impact reproductive outcomes. This highlights the importance of selenocysteine incorporation for GPX4 activity in male germ cells.
Endothelial Dysfunction and Cardiovascular Disease
Inhibition of cellular methyltransferases promotes endothelial cell activation by suppressing glutathione peroxidase 1 (GPX1) protein expression, linking negative regulation of selenoprotein synthesis to vascular pathology. Reduced GPX1 activity leads to increased oxidative stress and endothelial activation, which are early events in atherosclerosis. Thus, negative regulation of selenocysteine incorporation may contribute to cardiovascular disease risk.
Oxidative Stress-Related Diseases
Selenoproteins are major antioxidant enzymes, and their synthesis depends on selenocysteine incorporation. Negative regulation of this process reduces the cellular antioxidant capacity, potentially increasing susceptibility to oxidative stress-related diseases such as cancer and neurodegeneration. Understanding the mechanisms of negative regulation may reveal therapeutic strategies to enhance selenoprotein synthesis in disease states.
From negative regulation of selenocysteine incorporation-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does knockout of SCLY reduce selenocysteine incorporation? | SCLY knockout cell line via CRISPR |
| Does a point mutation in GPX4 affect fertility? | GPX4 point-mutation knock-in mouse |
| Can overexpression of SELENOP rescue selenium deficiency? | SELENOP overexpression cell model |
| Does tagged SEPHS1 interact with SCLY? | Knock-in of tagged SEPHS1 |
| Does inhibition of methyltransferases suppress GPX1? | GPX1 knockout and overexpression endothelial cells |
| Does SelB regulate bacterial selenocysteine incorporation? | SelB knockout E. coli |
How to Study the negative regulation of selenocysteine incorporation Process
| Method | What It Measures | Typical Application |
|---|---|---|
| Ribo-seq | Translation efficiency at UGA codons | Quantify selenocysteine incorporation vs termination |
| RNA-seq | mRNA expression of selenoprotein genes | Identify transcriptional changes in regulators |
| Proteomics | Selenoprotein abundance | Direct measurement of incorporation |
| Spectrophotometry | Selenium concentration | Assess selenium status |
| Western blot | Protein levels of GPX1, GPX4, SELENOP | Validate negative regulation effects [4,5] |
| CRISPR knockout | Gene function loss | Determine causal roles of regulators [3,8] |
| CRISPR knock-in | Tagged protein expression | Study protein interactions and localization |
| Overexpression | Gain-of-function effects | Test rescue or dominant-negative effects [4,5] |
Ribosome Profiling (Ribo-seq)
Ribo-seq can measure translation efficiency at UGA codons and quantify the frequency of selenocysteine incorporation versus termination. By comparing wild-type and mutant cells, researchers can determine how negative regulation affects recoding efficiency.
RNA Sequencing (RNA-seq)
RNA-seq measures mRNA levels of selenoprotein genes and regulators such as SELENOP, SCLY, and SEPHS1. It can reveal transcriptional changes that contribute to negative regulation of selenocysteine incorporation.
Proteomics and Selenoprotein Detection
Mass spectrometry-based proteomics can detect selenoproteins and quantify their abundance, providing a direct readout of selenocysteine incorporation. Labeling with selenium isotopes can track incorporation into specific proteins.
Spectrophotometric Selenium Determination
Spectrophotometric determination of selenium through triiodide anion allows quantification of selenium levels in cells and tissues, which is a key parameter for selenocysteine incorporation. This method is useful for correlating selenium status with incorporation efficiency.
How CRISPR Can Be Used to Study GO:1904570 negative regulation of selenocysteine incorporation
Knockout
CRISPR knockout of genes such as SCLY, SEPHS1, or SELENOP can abolish their function and reveal their necessity for selenocysteine incorporation [2,3]. For example, SCLY knockout cells show altered selenium recycling and reduced selenoprotein synthesis. Knockout of SelB in E. coli reduces selenocysteine incorporation and affects expression of virulence factors.
Point Mutation
Point mutations can be introduced to mimic disease-associated variants or to inactivate catalytic residues. For instance, a catalytically inactive mutant GPX4 can be expressed via CRISPR knock-in to study dominant-negative effects on fertility. Point mutations in SEPHS1 can disrupt selenophosphate synthesis and negatively regulate selenocysteine incorporation.
Knock-in
Knock-in of tagged versions of SCLY, SEPHS1, or SELENOP allows researchers to study protein interactions and localization in live cells. Tagged knock-in models can also be used to monitor real-time changes in protein levels in response to negative regulation.
Overexpression
Overexpression of SELENOP or GPX1 can rescue phenotypes caused by negative regulation of selenocysteine incorporation [2,5]. Conversely, overexpression of a dominant-negative GPX4 mutant can suppress wild-type function and reduce fertility. Overexpression models are useful for testing gain-of-function effects and therapeutic rescue strategies [4,5].
How EDITGENE Supports negative regulation of selenocysteine incorporation Research
Researchers studying negative regulation of selenocysteine incorporation-related genes often need to determine whether a candidate gene is causally involved in the process or is merely a bystander. This requires precise genetic manipulation, which can be achieved through CRISPR-based knockout, point mutation, knock-in, and overexpression models. EDITGENE provides end-to-end services to generate these models and to perform functional screening and bioinformatics analysis.
Contact EDITGENE today to design your custom CRISPR model for negative regulation of selenocysteine incorporation research.
Frequently Asked Questions About negative regulation of selenocysteine incorporation
What is GO:1904570?
GO:1904570 is the Gene Ontology term for negative regulation of selenocysteine incorporation, defined as any process that stops, prevents or reduces the frequency, rate or extent of selenocysteine incorporation.
What genes are involved in negative regulation of selenocysteine incorporation?
Key genes include SELENOP, SCLY, SEPHS1, SEPHS2, GPX4, GPX1, and SelB, which regulate selenium availability, selenophosphate synthesis, and translation recoding [2,3,4,8].
How does selenium affect selenocysteine incorporation?
Selenium is required for selenophosphate synthesis; when selenium is limited, negative regulation reduces selenocysteine incorporation to conserve this trace element [2,6].
What diseases are linked to negative regulation of selenocysteine incorporation?
Diseases include thyroid disorders, male infertility, endothelial dysfunction, and oxidative stress-related conditions such as cancer and neurodegeneration [1,4,5].
What is the role of selenoprotein P in selenocysteine incorporation?
Selenoprotein P transports selenium to tissues and interacts with selenocysteine lyase to regulate the selenium pool available for selenocysteine incorporation.
How can CRISPR be used to study negative regulation of selenocysteine incorporation?
CRISPR knockout, point mutation, knock-in, and overexpression models can be used to manipulate genes like SCLY, SEPHS1, and GPX4 and assess their effects on selenocysteine incorporation [3,4,8].
What methods measure selenocysteine incorporation?
Ribo-seq, RNA-seq, proteomics, and spectrophotometric selenium determination are commonly used to measure incorporation efficiency and selenium status [6,7].
What is the role of selenocysteine lyase in selenium metabolism?
Selenocysteine lyase recycles selenium from degraded selenoproteins and interacts with selenophosphate synthetase to regulate selenophosphate production [2,3].
Can negative regulation of selenocysteine incorporation be reversed?
Overexpression of SELENOP or GPX1 can rescue phenotypes caused by negative regulation, suggesting potential for therapeutic intervention [2,5].
What is the connection between GPX4 and male fertility?
GPX4 is a selenoprotein essential for sperm function; a dominant-negative mutant GPX4 reduces fertility, linking negative regulation of selenocysteine incorporation to male infertility.
Conclusion
GO:1904570, negative regulation of selenocysteine incorporation, is a critical biological process that controls the synthesis of selenoproteins in response to selenium availability and cellular demands. Dysregulation of this process is linked to thyroid disorders, male infertility, endothelial dysfunction, and oxidative stress-related diseases [1,4,5]. Understanding the molecular players such as SELENOP, SCLY, SEPHS1, and GPX4 provides a foundation for therapeutic targeting [2,3,4]. CRISPR-based models, including knockout, point mutation, knock-in, and overexpression, are indispensable for dissecting the causal roles of these genes in negative regulation [3,4,8]. EDITGENE offers comprehensive services to generate these models and to perform functional screening and bioinformatics analysis, accelerating research into selenocysteine incorporation and its regulation.
References
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- 3. da Silva MTA et al.. 2020. Trypanosomatid selenophosphate synthetase structure, function and interaction with selenocysteine lyase.. PLoS Negl Trop Dis 14(10):e0008091 PMID: 33017394
- 4. Ingold I et al.. 2015. Expression of a Catalytically Inactive Mutant Form of Glutathione Peroxidase 4 (Gpx4) Confers a Dominant-negative Effect in Male Fertility.. J Biol Chem 290(23):14668-78 PMID: 25922076
- 5. Barroso M et al.. 2014. Inhibition of cellular methyltransferases promotes endothelial cell activation by suppressing glutathione peroxidase 1 protein expression.. J Biol Chem 289(22):15350-62 PMID: 24719327
- 6. Bizerea-Spiridon O et al.. 2017. Spectrophotometric Determination of Selenium Through Triiodide Anion.. Clin Lab 63(5):887-899 PMID: 28627816
- 7. Chowdhury HM et al.. 2018. Aminoglycoside-mediated promotion of translation readthrough occurs through a non-stochastic mechanism that competes with translation termination.. Hum Mol Genet 27(2):373-384 PMID: 29177465
- 8. Yu H et al.. 2011. The involvement of SelB in the expression of cytotoxic necrotizing factor 1 in Escherichia coli.. FEBS Lett 585(12):1934-40 PMID: 21570972
