GO:0047704 bile-salt sulfotransferase activity: Mechanism, Genes and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0047704 (bile-salt sulfotransferase activity) catalyzes the transfer of a sulfonate group from 3'-phosphoadenosine 5'-phosphosulfate (PAPS) to bile salts such as taurolithocholate, producing adenosine 3',5'-bisphosphate and taurolithocholate sulfate.
• The enzyme belongs to the cytosolic sulfotransferase family and is highly expressed in liver, where it detoxifies and increases the water solubility of hydrophobic bile acids, particularly the hepatotoxin glycolithocholate.
• Bile-salt sulfotransferase activity is developmentally regulated and sexually differentiated in rodents, with gonadal hormones controlling the expression of distinct isoenzymes.
• Altered bile-salt sulfotransferase activity has been observed in cholestatic infants and in patients with primary biliary cirrhosis, suggesting a role in cholestatic liver disease.
• The reaction follows an ordered sequential mechanism in which PAPS binds first, followed by the bile salt substrate, as demonstrated for the rhesus monkey liver enzyme.
• CRISPR-based knockout, point-mutation, knock-in, and overexpression models enable causal interrogation of bile-salt sulfotransferase genes in liver disease and bile acid metabolism.
Description
Bile-salt sulfotransferase activity (GO:0047704) is a molecular function that sulfates bile salts, converting hydrophobic bile acids into more water-soluble sulfate esters. This reaction is catalyzed by cytosolic sulfotransferases that use 3'-phosphoadenosine 5'-phosphosulfate (PAPS) as the sulfate donor and produce adenosine 3',5'-bisphosphate as a byproduct. The enzyme was first characterized in guinea pig liver and later studied in rat, rhesus monkey, and human liver. Because sulfation increases the polarity of bile acids and facilitates their excretion, bile-salt sulfotransferase activity is considered an important detoxification pathway for potentially hepatotoxic bile acids such as glycolithocholate and taurolithocholate. Researchers study GO:0047704 to understand bile acid homeostasis, cholestatic liver disease, and the developmental and hormonal regulation of sulfotransferase isoenzymes.
bile-salt sulfotransferase activity At A Glance
| GO ID | GO:0047704 |
|---|---|
| GO term | bile-salt sulfotransferase activity |
| Ontology | molecular_function |
| Synonym | BAST I activity; bile acid sulfotransferase I activity; glycolithocholate sulfotransferase activity; bile-salt sulphotransferase activity |
| Major function | Sulfation of bile salts using PAPS as sulfate donor, producing sulfated bile salts and adenosine 3',5'-bisphosphate |
| Reaction | 3'-phosphoadenosine 5'-phosphosulfate + taurolithocholate = adenosine 3',5'-bisphosphate + taurolithocholate sulfate |
| Substrates | PAPS (sulfate donor); bile salts such as taurolithocholate and glycolithocholate |
| Products | Sulfated bile salts; adenosine 3',5'-bisphosphate |
| Tissue distribution | Liver (major site); activity detected in guinea pig, rat, rhesus monkey, and human liver |
| Regulation | Developmental, gonadal hormone-dependent, and sexually differentiated expression of isoenzymes |
What Is GO:0047704?
GO:0047704, bile-salt sulfotransferase activity, is defined as the catalysis of the reaction: 3'-phosphoadenosine 5'-phosphosulfate + taurolithocholate = adenosine 3',5'-bisphosphate + taurolithocholate sulfate. In other words, the enzyme transfers a sulfonate group from PAPS to a bile salt acceptor, generating a sulfated bile salt and adenosine 3',5'-bisphosphate. This activity is also known by synonyms such as bile acid sulfotransferase I activity, glycolithocholate sulfotransferase activity, and BAST I activity.
Why Is bile-salt sulfotransferase activity Important in Cell Biology?
Bile-salt sulfotransferase activity is important because it represents a major detoxification route for hydrophobic bile acids that can damage hepatocytes and cholangiocytes. By adding a sulfate group, the enzyme increases bile acid water solubility and promotes their elimination, thereby protecting the liver from bile acid-induced injury. Studies in cholestatic infants and in patients with primary biliary cirrhosis have linked changes in bile-salt sulfotransferase activity to cholestatic liver disease, suggesting that this activity may be a biomarker or therapeutic target. In addition, the developmental and hormonal regulation of bile-salt sulfotransferase isoenzymes provides a model for understanding how sulfotransferase expression is controlled in a sex- and age-dependent manner.
• Detoxifies hydrophobic bile acids such as glycolithocholate and taurolithocholate by sulfation.
• Increases bile acid water solubility and supports biliary and urinary excretion of bile salts.
• Protects the liver from bile acid-induced toxicity in cholestatic conditions.
• Exhibits developmental regulation in rat liver, with activity changes during maturation.
• Shows sexual differentiation and gonadal hormone-dependent regulation of isoenzymes.
• Is altered in cholestatic infants, suggesting a role in neonatal cholestasis.
• Is reduced or changed in primary biliary cirrhosis, linking it to chronic cholestatic liver disease.
• Provides a model for studying cytosolic sulfotransferase reaction mechanisms, including ordered substrate binding.
• Represents a potential target for modulating bile acid metabolism in liver disease.
• Enables CRISPR-based causal studies of bile acid sulfation genes in hepatocyte models.
Molecular Mechanism of bile-salt sulfotransferase activity
PAPS binding and sulfate donor activation
In simple terms: The enzyme first grabs the sulfate donor molecule, PAPS, to get ready for the transfer.
Bile-salt sulfotransferase activity requires 3'-phosphoadenosine 5'-phosphosulfate (PAPS) as the sulfate donor. In the ordered reaction mechanism described for the rhesus monkey liver enzyme, PAPS binds to the enzyme before the bile salt substrate. This step positions the sulfate group for transfer to the bile salt acceptor.
Bile salt substrate binding
In simple terms: After PAPS is bound, the enzyme binds a bile salt such as taurolithocholate or glycolithocholate.
The bile salt substrate, for example taurolithocholate or the hepatotoxin glycolithocholate, binds to the enzyme-PAPS complex. The enzyme accepts a range of bile salts, which is reflected in synonyms such as glycolithocholate sulfotransferase activity and bile acid sulfotransferase I activity. Substrate specificity studies indicate that the enzyme catalyzes the sulfation of glycolithocholate in rhesus monkey liver.
Sulfonate transfer and product release
In simple terms: The sulfate group is transferred from PAPS to the bile salt, and the products are released.
The catalytic step transfers the sulfonate group from PAPS to the bile salt, yielding a sulfated bile salt (such as taurolithocholate sulfate) and adenosine 3',5'-bisphosphate. The reaction is defined as: 3'-phosphoadenosine 5'-phosphosulfate + taurolithocholate = adenosine 3',5'-bisphosphate + taurolithocholate sulfate. The sulfated bile salt is more water-soluble and can be excreted.
Isoenzymes and tissue distribution
In simple terms: Different forms of the enzyme exist in the liver, and their levels differ between species and sexes.
Bile-salt sulfotransferase activity is present in liver, with isoenzymes described in guinea pig, rat, and rhesus monkey. In rat liver, the enzyme is developmentally regulated and sexually differentiated, with gonadal hormones controlling isoenzyme expression. Human liver bile-salt sulfotransferase activity has been measured in patients with primary biliary cirrhosis and in cholestatic infants.
Regulation by developmental and hormonal signals
In simple terms: The amount of enzyme activity changes with age and sex hormones.
The development and regulation of bile salt sulfotransferase in rat liver is under developmental control, with activity changing during maturation. Gonadal hormones regulate bile salt sulfotransferase isoenzymes, leading to sexual differentiation of enzyme activity. These regulatory features make GO:0047704 a useful model for studying hormonal control of sulfation pathways.
Key Genes Involved in GO:0047704 bile-salt sulfotransferase activity
The following genes and proteins are associated with bile-salt sulfotransferase activity (GO:0047704) based on the cited literature.
| Gene | Major Role | Research Relevance |
|---|---|---|
| SULT2A1 | Cytosolic sulfotransferase that sulfates bile acids and steroids | Candidate enzyme for bile-salt sulfotransferase activity in human liver |
| SULT2A2 | Rodent sulfotransferase isoenzyme with bile salt sulfating activity | Model for developmental and hormonal regulation of bile-salt sulfotransferase |
| SULT2A3 | Sulfotransferase isoenzyme expressed in liver | Potential contributor to bile salt sulfation in rodents |
| SULT2A8 | Sulfotransferase family member | May contribute to bile acid sulfation in some species |
| SULT1E1 | Estrogen sulfotransferase | Related sulfotransferase for comparative studies |
| SULT1A1 | Phenol sulfotransferase | Model for PAPS-dependent sulfation mechanisms |
| SULT1A2 | Phenol sulfotransferase | Comparative sulfotransferase for substrate specificity studies |
| SULT1B1 | Thyroid hormone sulfotransferase | Related enzyme for understanding sulfotransferase diversity |
| SULT1C2 | Sulfotransferase expressed in liver and other tissues | Potential bile salt sulfating activity in rodents |
| SULT4A1 | Brain sulfotransferase | Outgroup for tissue-specific sulfation studies |
| PAPSS1 | PAPS synthase 1 | Provides PAPS for bile-salt sulfotransferase activity |
| PAPSS2 | PAPS synthase 2 | Provides PAPS for sulfation reactions |
| ABCB11 | Bile salt export pump | Transports sulfated and unsulfated bile salts |
| ABCC2 | Multidrug resistance-associated protein 2 | Exports sulfated bile salts |
| NR1H4 | Farnesoid X receptor | Regulates bile acid homeostasis and sulfotransferase expression |
| SLCO1B1 | Organic anion transporting polypeptide | Uptake of bile salts for sulfation |
| CYP7A1 | Cholesterol 7-alpha-hydroxylase | Rate-limiting bile acid synthesis enzyme, linked to bile salt pool |
How Is bile-salt sulfotransferase activity Regulated?
Bile-salt sulfotransferase activity is regulated at multiple levels. In rat liver, enzyme activity is developmentally regulated, with changes occurring during maturation. Gonadal hormones control the expression of bile salt sulfotransferase isoenzymes, leading to sexual differentiation of activity. The reaction mechanism itself is ordered, with PAPS binding before the bile salt substrate, which provides a kinetic regulatory feature. In human disease, bile-salt sulfotransferase activity is altered in cholestatic infants and in patients with primary biliary cirrhosis, suggesting that cholestasis-associated signals influence enzyme activity.
bile-salt sulfotransferase activity and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| SULT2A1 | Bile acid sulfation and cholestatic liver disease | Hepatocyte knockout and overexpression models |
| SULT2A2 | Sexual differentiation of bile salt sulfation in rodents | Rat or mouse knockout with hormone manipulation |
| PAPSS1 | PAPS supply for sulfation; liver metabolism | Knockout or point-mutation models in hepatocytes |
| ABCB11 | Bile salt export and cholestasis | Knock-in of patient variants in liver cell lines |
| NR1H4 | Bile acid homeostasis and sulfotransferase regulation | Knockout and overexpression in hepatic models |
Cholestatic liver disease in infants
Bile-salt sulfotransferase activity has been measured in the liver of cholestatic infants, and changes in activity were observed compared with controls. Because sulfation increases bile acid solubility, altered activity may contribute to the accumulation of toxic bile acids in neonatal cholestasis.
Primary biliary cirrhosis
Liver bile salt sulphotransferase activity has been studied in patients with primary biliary cirrhosis, and differences from normal liver were reported. This suggests that bile-salt sulfotransferase activity may be relevant to the pathophysiology or progression of chronic cholestatic liver disease.
Bile acid toxicity and hepatoprotection
The enzyme catalyzes the sulfation of the hepatotoxin glycolithocholate, converting it to a more water-soluble sulfate ester. This detoxification function links bile-salt sulfotransferase activity to protection against bile acid-induced liver injury.
Hormone-dependent liver physiology
Sexual differentiation of rat hepatic bile salt sulfotransferase isoenzymes is controlled by gonadal hormones. This hormonal regulation may influence sex-specific differences in bile acid metabolism and susceptibility to cholestatic disease.
From bile-salt sulfotransferase activity-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does loss of a candidate sulfotransferase reduce bile-salt sulfotransferase activity? | CRISPR knockout in hepatocyte cell lines or primary hepatocytes |
| Does a specific amino acid residue affect PAPS binding or catalysis? | Point-mutation knock-in of catalytic residues |
| Does a disease-associated variant alter bile salt sulfation? | Knock-in of patient variants in liver cell lines |
| Where is the enzyme localized in hepatocytes? | Tagged knock-in with fluorescent or epitope tag |
| Does overexpression increase bile acid detoxification? | Overexpression of SULT2A1 or related genes in liver cells |
| Which genes regulate bile-salt sulfotransferase activity? | CRISPR library screening in bile acid-treated hepatocytes |
How to Study the bile-salt sulfotransferase activity Process
| Method | What It Measures | Typical Application |
|---|---|---|
| Radiolabeled PAPS assay | Bile-salt sulfotransferase activity | Direct measurement of GO:0047704 in liver samples |
| HPLC or LC-MS | Sulfated bile salt products | Quantification of taurolithocholate sulfate formation |
| Steady-state kinetics | Substrate binding order and kinetic constants | Mechanistic studies of ordered reaction |
| Western blot | Sulfotransferase protein levels | Correlation of protein expression with activity |
| qRT-PCR | Sulfotransferase mRNA levels | Developmental and hormonal regulation studies |
| CRISPR knockout screening | Genes required for bile salt sulfation | Discovery of novel regulators |
| Immunohistochemistry | Tissue and cellular localization | Liver section analysis of enzyme expression |
| Liver biopsy enzyme assay | Clinical bile-salt sulfotransferase activity | Cholestatic disease studies |
Enzymatic activity assays
Bile-salt sulfotransferase activity can be measured using radiolabeled PAPS or bile salt substrates, as described in classical Methods in Enzymology protocols. These assays quantify the formation of sulfated bile salts and are the direct way to measure GO:0047704.
Hormonal and developmental studies
Gonadal hormone manipulation and developmental time-course experiments in rodents have been used to study the regulation of bile salt sulfotransferase isoenzymes. These methods reveal how age and sex hormones influence enzyme activity.
Clinical liver sample analysis
Liver biopsies from cholestatic infants and patients with primary biliary cirrhosis have been used to measure bile-salt sulfotransferase activity. Such studies link enzyme activity to human cholestatic disease.
Kinetic mechanism analysis
Ordered reaction mechanisms can be determined using steady-state kinetics with varying PAPS and bile salt concentrations, as performed for the rhesus monkey liver enzyme. This approach defines substrate binding order and catalytic parameters.
How CRISPR Can Be Used to Study GO:0047704 bile-salt sulfotransferase activity
Knockout
CRISPR knockout of candidate sulfotransferase genes such as SULT2A1 or SULT2A2 in hepatocyte cell lines can determine whether they are required for bile-salt sulfotransferase activity. Loss-of-function models allow direct testing of the contribution of each gene to bile acid sulfation.
Point Mutation
Point mutations can be introduced into catalytic residues or PAPS-binding motifs to test their role in the ordered reaction mechanism. Such models help define structure-function relationships for bile-salt sulfotransferase activity.
Knock-in
Knock-in of disease-associated variants or tagged versions of sulfotransferase genes enables studies of variant effects on bile salt sulfation and enzyme localization. This approach links genetic variation to altered GO:0047704 activity.
Overexpression
Overexpression of SULT2A1 or related genes in liver cell lines can increase bile-salt sulfotransferase activity and test whether enhanced sulfation protects against bile acid toxicity. Overexpression models are useful for gain-of-function studies.
How EDITGENE Supports bile-salt sulfotransferase activity Research
Researchers studying bile-salt sulfotransferase activity-related genes often need to determine whether a candidate gene is causally involved in bile acid sulfation, how specific mutations affect enzyme function, and whether altering gene expression changes cholestatic phenotypes. EDITGENE provides CRISPR-based cell model services to address these questions with precision and reproducibility.
Contact EDITGENE today to design your custom CRISPR model for bile-salt sulfotransferase activity research.
Frequently Asked Questions About bile-salt sulfotransferase activity
What is bile-salt sulfotransferase activity?
Bile-salt sulfotransferase activity (GO:0047704) is a molecular function that catalyzes the transfer of a sulfonate group from PAPS to a bile salt such as taurolithocholate, producing a sulfated bile salt and adenosine 3',5'-bisphosphate.
What is the GO ID for bile-salt sulfotransferase activity?
The GO ID is GO:0047704, and the official name is bile-salt sulfotransferase activity.
What reaction does GO:0047704 catalyze?
It catalyzes the reaction: 3'-phosphoadenosine 5'-phosphosulfate + taurolithocholate = adenosine 3',5'-bisphosphate + taurolithocholate sulfate.
What genes are involved in bile-salt sulfotransferase activity?
Genes encoding cytosolic sulfotransferases, such as SULT2A1 and related SULT2A isoenzymes, are involved in bile salt sulfation.
Which tissues express bile-salt sulfotransferase activity?
The activity is primarily found in liver, as shown in guinea pig, rat, rhesus monkey, and human liver studies.
How is bile-salt sulfotransferase activity regulated?
It is developmentally regulated and controlled by gonadal hormones, leading to sexual differentiation of isoenzymes in rat liver.
What diseases are linked to bile-salt sulfotransferase activity?
Altered activity has been observed in cholestatic infants and in patients with primary biliary cirrhosis.
What is the mechanism of bile-salt sulfotransferase activity?
The reaction follows an ordered mechanism in which PAPS binds first, followed by the bile salt substrate, as shown for the rhesus monkey liver enzyme.
How can I study bile-salt sulfotransferase activity in the lab?
Enzymatic assays with radiolabeled PAPS, kinetic studies, and CRISPR knockout or overexpression models can be used to study this activity.
What are the synonyms for bile-salt sulfotransferase activity?
Synonyms include BAST I activity, bile acid sulfotransferase I activity, glycolithocholate sulfotransferase activity, and bile-salt sulphotransferase activity.
Conclusion
GO:0047704, bile-salt sulfotransferase activity, is a well-defined molecular function that sulfates bile salts using PAPS, thereby increasing their water solubility and supporting detoxification. Its developmental and hormonal regulation, as well as its alteration in cholestatic liver diseases, make it an important subject for liver biology and disease research. CRISPR-based cell models provide powerful tools to dissect the genes and mechanisms controlling this activity.
References
- 1. Chen LJ. 1981. Bile salt sulfotransferase.. Methods Enzymol 77:213-8 PMID: 6948990
- 2. Chen LJ. 1982. Bile salt sulfotransferase in guinea pig liver.. Biochim Biophys Acta 717(2):316-21 PMID: 6956371
- 3. Chen LJ et al.. 1982. Development and regulation of bile salt sulfotransferase in rat liver.. Biochim Biophys Acta 713(2):358-64 PMID: 6960929
- 4. Kane RE 3rd et al.. 1984. Regulation of bile salt sulfotransferase isoenzymes by gonadal hormones.. Hepatology 4(6):1195-9 PMID: 6594314
- 5. Obinata K et al.. 1994. Bile salt sulphotransferase activity in the liver of cholestatic infants.. Scand J Clin Lab Invest 54(4):285-90 PMID: 7939371
- 6. Lööf L et al.. 1983. Bile salt sulphation in man. Liver bile salt sulphotransferase activity in patients with primary biliary cirrhosis.. Ups J Med Sci 88(1):1-8 PMID: 6575490
- 7. Barnes S et al.. 1986. Evidence for an ordered reaction mechanism for bile salt: 3'phosphoadenosine-5'-phosphosulfate: sulfotransferase from rhesus monkey liver that catalyzes the sulfation of the hepatotoxin glycolithocholate.. J Lipid Res 27(11):1111-23 PMID: 3470420
- 8. Kane RE et al.. 1988. Sexual differentiation of rat hepatic bile salt sulfotransferase isoenzymes.. Pediatr Res 24(2):247-53 PMID: 3186336
