GO:0033867 Fas-activated serine/threonine kinase activity: Mechanism, Genes and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0033867 describes the molecular function of Fas-activated serine/threonine kinase (FASTK), which catalyzes ATP-dependent phosphorylation of serine/threonine residues on protein substrates.
• FASTK was originally identified as a kinase that phosphorylates TIA-1 during Fas-mediated apoptosis, linking it to RNA metabolism and cell death.
• FASTK regulates alternative splicing of Fas pre-mRNA by synergizing with TIA-1/TIAR proteins, thereby influencing apoptotic signaling.
• FASTK is critical for cardiac mitochondrial complex I integrity and function during ischemia/reperfusion injury.
• Genetic ablation of FASTK ameliorates alcoholic liver disease and obesity-related metabolic disorders via SIRT1 signaling.
• Small-molecule inhibitors of FASTK show antiproliferative activity in breast cancer cells, highlighting its therapeutic potential.
Description
Fas-activated serine/threonine kinase (FASTK) is a nuclear-encoded protein kinase that was initially discovered as an enzyme activated during Fas-mediated apoptosis. The Gene Ontology term GO:0033867 captures its catalytic activity: the transfer of a phosphate group from ATP to serine or threonine residues on protein substrates, yielding ADP and a phosphorylated protein. This activity places FASTK at the intersection of apoptotic signaling, RNA processing, and mitochondrial gene expression. Understanding GO:0033867 is essential for researchers studying cell death, post-transcriptional regulation, and mitochondrial dysfunction in disease contexts such as cancer, ischemia/reperfusion injury, and metabolic disorders. The kinase domain of FASTK defines its enzymatic function, but its biological roles extend to splicing regulation and mitochondrial RNA stability through interactions with TIA-1/TIAR and other RNA-binding proteins.
Fas-activated serine/threonine kinase activity At A Glance
| GO ID | GO:0033867 |
|---|---|
| GO term | Fas-activated serine/threonine kinase activity |
| Ontology | molecular_function |
| Synonym | ATP:Fas-activated serine/threonine protein phosphotransferase activity, FAST, FASTK, STK10 |
| Major function | Phosphorylation of serine/threonine residues on protein substrates using ATP |
| Reaction | ATP + Fas-activated serine/threonine protein = ADP + Fas-activated serine/threonine phosphoprotein |
| Related processes | Apoptosis, RNA splicing, mitochondrial gene expression |
| Representative gene | FASTK (Fas-activated serine/threonine kinase) |
What Is GO:0033867?
GO:0033867, Fas-activated serine/threonine kinase activity, is defined as the catalysis of the reaction: ATP + Fas-activated serine/threonine protein = ADP + Fas-activated serine/threonine phosphoprotein. In other words, it is the enzymatic activity by which FASTK transfers a phosphate group from ATP to serine or threonine residues on target proteins, thereby modulating their function. This activity is synonymous with ATP:Fas-activated serine/threonine protein phosphotransferase activity, FAST, FASTK, and STK10.
Why Is Fas-activated serine/threonine kinase activity Important in Cell Biology?
GO:0033867 is important because FASTK-mediated phosphorylation directly influences key cellular decisions such as survival versus apoptosis, alternative splicing of death receptors, and mitochondrial energy metabolism. Dysregulation of FASTK activity has been implicated in cardiac ischemia/reperfusion injury, alcoholic liver disease, obesity-related metabolic disorders, and breast cancer proliferation. Thus, understanding this kinase activity provides mechanistic insights into disease pathogenesis and offers a target for therapeutic intervention.
• FASTK phosphorylates TIA-1 during Fas-mediated apoptosis, linking kinase activity to programmed cell death.
• FASTK synergizes with TIA-1/TIAR to regulate Fas alternative splicing, affecting apoptotic sensitivity.
• FASTK is required for cardiac mitochondrial complex I functional integrity during ischemia/reperfusion.
• Genetic ablation of FASTK ameliorates alcoholic liver disease via HuR-SIRT1 mRNA complex stability.
• FASTK ablation improves obesity-related hepatic glucose and lipid metabolic disorders through SIRT1 signaling.
• Inhibition of FASTK reduces proliferation in human breast cancer cells.
• FASTK domains, such as FASTKD3, are involved in post-transcriptional regulation of mitochondrial gene expression.
• The kinase activity is ATP-dependent and targets serine/threonine residues, making it a classic protein kinase.
• FASTK is a nuclear-encoded protein that also localizes to mitochondria, bridging nuclear and mitochondrial gene regulation.
• Small-molecule inhibitors of FASTK are being explored as anticancer agents.
Molecular Mechanism of Fas-activated serine/threonine kinase activity
Substrate recognition and binding
In simple terms: FASTK grabs onto specific proteins that have serine or threonine residues it can phosphorylate.
FASTK recognizes target proteins such as TIA-1, a RNA-binding protein involved in apoptosis and splicing. The kinase domain of FASTK mediates substrate binding, and this interaction is critical for downstream phosphorylation events.
ATP-dependent phosphorylation
In simple terms: FASTK uses ATP as an energy source to attach a phosphate group onto its target protein.
The catalytic reaction transfers the gamma-phosphate of ATP to the hydroxyl group of serine or threonine residues on the substrate, producing ADP and a phosphoprotein. This is the defining biochemical activity of GO:0033867.
Regulation by Fas signaling
In simple terms: FASTK becomes active when the Fas receptor triggers a death signal.
FASTK was originally identified as an enzyme activated during Fas-mediated apoptosis, and its kinase activity is stimulated upon Fas ligation. This links GO:0033867 directly to extrinsic apoptotic pathways.
Synergy with TIA-1/TIAR in splicing
In simple terms: FASTK works together with TIA-1 and TIAR to control how Fas mRNA is spliced.
FASTK synergizes with TIA-1/TIAR proteins to regulate alternative splicing of Fas pre-mRNA, influencing the production of pro- or anti-apoptotic Fas isoforms. This function depends on the kinase activity of FASTK.
Role in mitochondrial gene expression
In simple terms: FASTK family members help regulate mitochondrial RNA processing and stability.
FASTKD3, a related kinase domain-containing protein, is involved in post-transcriptional regulation of mitochondrial gene expression. This suggests that FASTK-like activities contribute to mitochondrial RNA metabolism.
Key Genes Involved in GO:0033867 Fas-activated serine/threonine kinase activity
The following genes and proteins are directly implicated in Fas-activated serine/threonine kinase activity and its downstream biology.
| Gene | Major Role | Research Relevance |
|---|---|---|
| FASTK | Encodes the Fas-activated serine/threonine kinase; phosphorylates TIA-1 and regulates splicing | Core enzyme for GO:0033867; knockout and overexpression models available |
| TIA1 | RNA-binding protein phosphorylated by FASTK; regulates apoptosis and splicing | Substrate of FASTK; key to understanding downstream effects |
| TIAR (TIAL1) | RNA-binding protein that synergizes with FASTK and TIA-1 | Modulates Fas alternative splicing |
| FASTKD3 | Mitochondrial protein with kinase domain; regulates mitochondrial gene expression | Related family member; links to mitochondrial RNA processing |
| SIRT1 | NAD-dependent deacetylase; modulated by FASTK ablation in liver | Mediates metabolic benefits of FASTK knockout |
| HuR (ELAVL1) | RNA-binding protein; interacts with SIRT1 mRNA in FASTK-dependent manner | Involved in alcoholic liver disease and mRNA stability |
| FAS | Death receptor; its alternative splicing is regulated by FASTK | Upstream activator of FASTK; target of splicing regulation |
| Complex I subunits (e.g., NDUFS1, NDUFA9) | Mitochondrial respiratory chain components | FASTK governs complex I integrity in ischemia/reperfusion |
| STK10 | Serine/threonine kinase; synonym for FASTK in some annotations | Potential alternative name; may share kinase activity |
| CASP8 | Caspase-8; downstream of Fas signaling | Links FASTK activity to apoptosis execution |
| CASP3 | Caspase-3; executioner caspase | Apoptosis marker in FASTK studies |
| BCL2 | Anti-apoptotic protein | Modulated in FASTK-dependent apoptosis |
| BAX | Pro-apoptotic protein | Modulated in FASTK-dependent apoptosis |
| NDUFA9 | Complex I subunit | Used as marker for mitochondrial integrity in FASTK studies |
| SDHA | Complex II subunit | Control for mitochondrial function in FASTK studies |
| ATP5A | Complex V subunit | Control for mitochondrial function |
| GAPDH | Glycolytic enzyme | Loading control in FASTK experiments |
| ACTB | Beta-actin | Loading control in FASTK experiments |
How Is Fas-activated serine/threonine kinase activity Regulated?
FASTK activity is regulated at multiple levels. Its kinase activity is stimulated by Fas receptor ligation during apoptosis. At the post-transcriptional level, FASTK itself is subject to alternative splicing and its mRNA stability may be influenced by RNA-binding proteins. In mitochondria, FASTK family members such as FASTKD3 are regulated by unknown signals that control mitochondrial RNA processing. Additionally, metabolic stress such as alcohol exposure or obesity alters FASTK expression and its downstream effects on SIRT1 signaling.
Fas-activated serine/threonine kinase activity and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| FASTK | Cardiac ischemia/reperfusion injury | Cardiomyocyte-specific FASTK knockout mice |
| FASTK | Alcoholic liver disease | Liver-specific FASTK knockout mice |
| FASTK | Obesity-related metabolic disorders | FASTK knockout mice fed high-fat diet |
| FASTK | Breast cancer | FASTK knockdown or inhibitor-treated breast cancer cell lines |
| FASTK | Apoptosis and splicing defects | T-cell lines with FASTK knockout |
FASTK in cardiac ischemia/reperfusion injury
FASTK governs cardiac mitochondrial complex I functional integrity during ischemia/reperfusion, and its loss is protective against mitochondrial dysfunction. This positions FASTK as a potential therapeutic target in myocardial infarction.
FASTK in metabolic liver disease
Genetic ablation of FASTK ameliorates alcoholic liver disease through modulating HuR-SIRT1 mRNA complex stability. Similarly, FASTK knockout improves obesity-related hepatic glucose and lipid metabolic disorders via SIRT1 signaling. These findings highlight FASTK as a modulator of hepatic metabolism.
FASTK in cancer
Thienopyrimidine-chalcone hybrid molecules that inhibit FASTK show antiproliferative activity in human breast cancer cells. This suggests that FASTK kinase activity is required for cancer cell proliferation and that its inhibition may be therapeutically beneficial.
FASTK in apoptosis and splicing
FASTK phosphorylates TIA-1 during Fas-mediated apoptosis and synergizes with TIA-1/TIAR to regulate Fas alternative splicing. Dysregulation of this pathway can lead to altered apoptotic responses, contributing to autoimmune and lymphoproliferative disorders.
From Fas-activated serine/threonine kinase activity-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| What is the role of FASTK kinase activity in apoptosis? | FASTK knockout cell lines (e.g., Jurkat) |
| How does FASTK regulate Fas alternative splicing? | FASTK knockout or knockdown cells with minigene reporters |
| Does FASTK protect against cardiac ischemia/reperfusion injury? | Cardiomyocyte-specific FASTK knockout mice |
| How does FASTK ablation affect alcoholic liver disease? | Liver-specific FASTK knockout mice |
| Does FASTK inhibition reduce breast cancer proliferation? | Breast cancer cell lines treated with FASTK inhibitors |
| What is the effect of FASTK on mitochondrial gene expression? | FASTKD3 knockout cells |
How to Study the Fas-activated serine/threonine kinase activity Process
| Method | What It Measures | Typical Application |
|---|---|---|
| In vitro kinase assay | Phosphorylation of substrate by FASTK | Confirming GO:0033867 activity |
| RNA immunoprecipitation (RIP) | Binding of FASTK to target RNAs | Identifying splicing targets |
| RNA-seq | Global changes in gene expression and splicing | Assessing FASTK-dependent splicing networks |
| Seahorse respirometry | Mitochondrial oxygen consumption | Evaluating complex I function |
| Blue native PAGE | Mitochondrial respiratory chain supercomplexes | Assessing complex I integrity |
| Glucose tolerance test | Whole-body glucose handling | Metabolic phenotyping of FASTK KO mice |
| Lipid profiling | Hepatic lipid content | Studying obesity-related disorders |
| Cell proliferation assay | Cell growth and viability | Testing FASTK inhibitors in cancer cells |
Kinase activity assays
In vitro kinase assays using recombinant FASTK and substrate proteins such as TIA-1 can measure phosphate incorporation from radiolabeled ATP. These assays are essential to confirm GO:0033867 activity.
RNA immunoprecipitation and splicing analysis
RNA immunoprecipitation (RIP) followed by RT-PCR or RNA-seq can identify RNAs bound by FASTK and its partners, and assess alternative splicing changes. This is key to understanding how FASTK regulates Fas splicing.
Mitochondrial functional assays
Seahorse respirometry, blue native PAGE, and complex I activity assays can measure mitochondrial function in FASTK knockout or overexpression models. These methods link FASTK activity to mitochondrial integrity.
Metabolic phenotyping
Glucose tolerance tests, insulin tolerance tests, and lipid profiling in FASTK knockout mice can reveal metabolic consequences of loss of kinase activity. These are standard for studying liver and metabolic diseases.
How CRISPR Can Be Used to Study GO:0033867 Fas-activated serine/threonine kinase activity
Knockout
CRISPR-Cas9 knockout of FASTK in cell lines or mice abolishes its kinase activity, enabling studies of loss-of-function phenotypes in apoptosis, splicing, and metabolism. For example, FASTK knockout mice are protected from alcoholic liver disease and obesity-related metabolic disorders.
Point Mutation
Introducing point mutations in the catalytic domain of FASTK (e.g., K48A) can generate kinase-dead mutants to dissect phosphorylation-dependent versus independent functions. Such models are valuable for separating GO:0033867 activity from scaffolding roles.
Knock-in
Knock-in of tagged FASTK (e.g., FLAG or HA) allows for affinity purification and identification of interacting proteins and substrates. This approach can reveal new components of the FASTK signaling network.
Overexpression
Overexpression of wild-type or mutant FASTK in cell lines can enhance kinase activity and amplify downstream effects, such as increased TIA-1 phosphorylation or altered Fas splicing. This is useful for gain-of-function studies.
How EDITGENE Supports Fas-activated serine/threonine kinase activity Research
Researchers studying Fas-activated serine/threonine kinase activity-related genes often need to determine whether a candidate gene is causally involved in apoptosis, RNA splicing, or mitochondrial function. EDITGENE provides a comprehensive suite of CRISPR-based services to generate precisely engineered cell and animal models, enabling rigorous functional validation of GO:0033867 and its associated pathways.
Contact EDITGENE today to design your custom CRISPR model for Fas-activated serine/threonine kinase activity research.
Frequently Asked Questions About Fas-activated serine/threonine kinase activity
What is Fas-activated serine/threonine kinase activity?
It is the enzymatic activity defined by GO:0033867, where FASTK transfers a phosphate group from ATP to serine or threonine residues on target proteins, such as TIA-1.
What genes are involved in Fas-activated serine/threonine kinase activity?
The primary gene is FASTK, which encodes the kinase. Related genes include TIA1, TIAR, and FASTKD3, which interact with or share similar domains.
What diseases are associated with FASTK?
FASTK has been implicated in cardiac ischemia/reperfusion injury, alcoholic liver disease, obesity-related metabolic disorders, and breast cancer.
How is FASTK activated?
FASTK is activated during Fas-mediated apoptosis, upon Fas receptor ligation.
What is the role of FASTK in apoptosis?
FASTK phosphorylates TIA-1 and regulates Fas alternative splicing, thereby influencing apoptotic cell death.
Can FASTK be targeted for cancer therapy?
Inhibitors of FASTK show antiproliferative activity in breast cancer cells, suggesting potential therapeutic value.
What are the substrates of FASTK?
TIA-1 is a well-characterized substrate of FASTK; other substrates may exist but are less defined.
How does FASTK affect mitochondria?
FASTK governs cardiac mitochondrial complex I integrity, and related FASTKD3 regulates mitochondrial gene expression.
What model systems are used to study FASTK?
Knockout mice, cell lines, and in vitro kinase assays are commonly used.
What are the synonyms for GO:0033867?
Synonyms include ATP:Fas-activated serine/threonine protein phosphotransferase activity, FAST, FASTK, and STK10.
Conclusion
GO:0033867, Fas-activated serine/threonine kinase activity, represents a critical enzymatic function that bridges apoptosis, RNA splicing, and mitochondrial metabolism. FASTK, the enzyme responsible, phosphorylates TIA-1 and regulates Fas alternative splicing, while also impacting cardiac and hepatic metabolic diseases. The availability of CRISPR knockout models and small-molecule inhibitors underscores its potential as a therapeutic target. Continued research into this kinase activity will likely reveal new insights into cell death and metabolic regulation.
References
- 2. Chen X et al.. 2020. Fas-Activated Serine/Threonine Kinase Governs Cardiac Mitochondrial Complex I Functional Integrity in Ischemia/Reperfusion Heart.. Front Cell Dev Biol 8:630421 PMID: 33585470
- 3. Tian Q et al.. 1995. Fas-activated serine/threonine kinase (FAST) phosphorylates TIA-1 during Fas-mediated apoptosis.. J Exp Med 182(3):865-74 PMID: 7544399
- 4. Zhang F et al.. 2021. Genetic ablation of fas-activated serine/threonine kinase ameliorates alcoholic liver disease through modulating HuR-SIRT1 mRNA complex stability.. Free Radic Biol Med 166:201-211 PMID: 33610658
- 5. Izquierdo JM et al.. 2007. Fas-activated serine/threonine kinase (FAST K) synergizes with TIA-1/TIAR proteins to regulate Fas alternative splicing.. J Biol Chem 282(3):1539-43 PMID: 17135269
- 6. Boehm E et al.. 2016. Role of FAST Kinase Domains 3 (FASTKD3) in Post-transcriptional Regulation of Mitochondrial Gene Expression.. J Biol Chem 291(50):25877-25887 PMID: 27789713
- 7. Zhang F et al.. 2020. Genetic ablation of Fas-activated serine/threonine kinase ameliorates obesity-related hepatic glucose and lipid metabolic disorders via sirtuin-1 signaling.. Biochem Biophys Res Commun 529(4):1066-1072 PMID: 32819566
- 8. Khan NS et al.. 2018. Thienopyrimidine-Chalcone Hybrid Molecules Inhibit Fas-Activated Serine/Threonine Kinase: An Approach To Ameliorate Antiproliferation in Human Breast Cancer Cells.. Mol Pharm 15(9):4173-4189 PMID: 30040903
