GO:0046722 lactic acid secretion: Biological Process, Genes, Functions and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0046722 (lactic acid secretion) is the controlled release of lactic acid (2-hydroxypropanoic acid) by a cell or tissue [QuickGO definition].
• Lactic acid secretion occurs in diverse biological contexts, including milk fat synthesis in ruminants, saliva, sweat, and microbial fermentation.
• Lactic acid bacteria are widely used in dairy fermentation, and their genomic modifications can alter lactic acid secretion.
• Lactic acid secretion can influence host physiology, such as milk fat composition in cows and skin pH in atopic dermatitis.
• Pathogens like Escherichia coli O157:H7 can respond to lactic acid by altering membrane lipids and acid resistance.
• Human milk contains lactic acid bacteria, suggesting a role in infant health.
Description
Lactic acid secretion (GO:0046722) is a biological process defined as the controlled release of lactic acid, 2-hydroxypropanoic acid, by a cell or a tissue. This process is fundamental to many physiological and pathological contexts, ranging from microbial fermentation to mammalian metabolism. In ruminants, lactic acid secretion is linked to milk fat synthesis, as intraruminal infusions of lactic acid affect the secretion of component fatty acids of milk fat. In humans, lactic acid is secreted in saliva and sweat, where it can serve as a biomarker for physiological monitoring. Additionally, lactic acid bacteria are key players in dairy fermentation, and their genomic modifications can modulate lactic acid secretion. Understanding the mechanisms and regulation of lactic acid secretion is therefore important for agriculture, food science, and human health.
lactic acid secretion At A Glance
| GO ID | GO:0046722 |
|---|---|
| GO term | lactic acid secretion |
| Ontology | biological_process |
| Synonym | lactate secretion |
| Definition | The controlled release of lactic acid, 2-hydroxypropanoic acid, by a cell or a tissue. |
| Major function | Export of lactic acid to the extracellular environment |
| Organisms | Bacteria, mammals, and other eukaryotes |
| Related processes | Fermentation, acid resistance, milk fat synthesis, sweat and saliva secretion |
What Is GO:0046722?
Lactic acid secretion (GO:0046722) refers to the controlled release of lactic acid, also known as 2-hydroxypropanoic acid, from a cell or tissue into its surroundings. This process is distinct from lactic acid production, as it specifically involves the export or secretion of the molecule across cellular membranes. The QuickGO definition emphasizes the controlled nature of this release, implying regulation by cellular machinery. Lactic acid secretion is observed in various organisms, from bacteria to mammals, and plays roles in fermentation, acid-base balance, and intercellular signaling.
Why Is lactic acid secretion Important in Cell Biology?
Lactic acid secretion is important because it affects diverse biological processes, from microbial fermentation to mammalian physiology. In dairy science, lactic acid bacteria are essential for fermentation, and their lactic acid secretion influences product quality. In ruminants, lactic acid secretion impacts milk fat composition, which is economically important. In human health, lactic acid secretion in sweat can be monitored for physiological status, and in saliva it may relate to oral health. Moreover, lactic acid can influence pathogen behavior, such as Escherichia coli O157:H7 acid resistance, and skin pH in atopic dermatitis. Thus, understanding lactic acid secretion has broad implications for agriculture, food safety, and medicine.
• Lactic acid secretion is central to dairy fermentation by lactic acid bacteria.
• It affects milk fat synthesis in cows, influencing milk quality.
• Lactic acid in saliva may play a role in oral biology.
• Sweat lactic acid secretion can be used for non-invasive monitoring.
• Lactic acid can modulate pathogen acid resistance, impacting food safety.
• Skin pH regulation by lactic acid is relevant to atopic dermatitis.
• Human milk contains lactic acid bacteria, suggesting a role in infant health.
• Lactic acid secretion is a target for genomic modification in industrial bacteria.
What Happens During lactic acid secretion?
Lactic acid production and intracellular accumulation
In simple terms: Cells first make lactic acid inside themselves.
Lactic acid is produced through fermentation or metabolic pathways, leading to its accumulation within the cell. In lactic acid bacteria, this production is a key part of dairy fermentation. In mammals, lactic acid can be produced in various tissues, including muscle and mammary glands.
Transport across the cell membrane
In simple terms: The cell then moves lactic acid from inside to outside.
Lactic acid is transported across the cell membrane via specific transporters or channels. This step is controlled and can be regulated by cellular signals. In bacteria, lactic acid secretion is essential for maintaining intracellular pH and energy balance.
Release into extracellular environment
In simple terms: Lactic acid is released into the surroundings.
Once outside, lactic acid can affect the local environment, such as lowering pH. In sweat, lactic acid secretion can be measured as a biomarker. In saliva, lactic acid secretion contributes to the oral environment.
Physiological effects and regulation
In simple terms: The released lactic acid can have various effects on the body or environment.
Secreted lactic acid can influence host physiology, such as milk fat composition in cows or skin pH in atopic dermatitis. It can also affect microbial communities and pathogen behavior.
Key Genes Involved in GO:0046722 lactic acid secretion
The following genes and proteins are involved in or related to lactic acid secretion, based on published literature.
| Gene | Major Role | Research Relevance |
|---|---|---|
| LDHA | Lactate dehydrogenase A, converts pyruvate to lactate | Key enzyme in lactic acid production, relevant to cancer metabolism and fermentation |
| MCT1 (SLC16A1) | Monocarboxylate transporter 1, facilitates lactate transport | Involved in lactate secretion and uptake in various tissues |
| MCT4 (SLC16A3) | Monocarboxylate transporter 4, mediates lactate export | Important for lactic acid secretion in glycolytic cells |
| LdhB | Lactate dehydrogenase B | May influence lactate levels and secretion |
| LdhC | Lactate dehydrogenase C | Testis-specific, potential role in lactate metabolism |
| SLC16A7 | Monocarboxylate transporter 2 | Lactate transport in specific tissues |
| SLC16A8 | Monocarboxylate transporter 3 | Lactate transport in retina and other tissues |
| SLC16A6 | Monocarboxylate transporter 7 | Lactate transport |
| SLC16A5 | Monocarboxylate transporter 6 | Lactate transport |
| SLC16A4 | Monocarboxylate transporter 5 | Lactate transport |
| SLC16A11 | Monocarboxylate transporter 11 | Lactate transport, associated with type 2 diabetes |
| SLC16A12 | Monocarboxylate transporter 12 | Lactate transport, associated with cataract |
| SLC16A13 | Monocarboxylate transporter 13 | Lactate transport |
| SLC16A14 | Monocarboxylate transporter 14 | Lactate transport |
| SLC16A2 | Monocarboxylate transporter 8 | Thyroid hormone transport, not lactate-specific |
| SLC16A10 | Monocarboxylate transporter 10 | Aromatic amino acid transport |
| SLC16A9 | Monocarboxylate transporter 9 | Carnitine transport |
| SLC16A1-AS1 | Antisense RNA to SLC16A1 | Potential regulator of MCT1 expression |
How Is lactic acid secretion Regulated?
Lactic acid secretion is regulated at multiple levels. In lactic acid bacteria, genomic modifications can alter secretion pathways. In mammals, hormones and metabolic signals may influence lactic acid secretion, as seen in milk fat synthesis where intraruminal infusions of volatile fatty acids and lactic acid affect milk fat composition. Additionally, environmental factors such as pH can regulate lactic acid secretion and its effects.
lactic acid secretion and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| SLC16A1 | Lactic acid transport in cancer | Knockout in cancer cell lines |
| SLC16A3 | Lactic acid secretion in inflammation | Overexpression in epithelial cells |
| LDHA | Cancer metabolism | Point mutation to alter activity |
| SLC16A11 | Type 2 diabetes | Knock-in of risk variant |
| SLC16A12 | Cataract | Knockout in lens epithelial cells |
Atopic dermatitis and skin pH
Lactic acid secretion contributes to skin pH regulation, and alterations in pH are associated with atopic dermatitis. Understanding lactic acid secretion in skin may lead to new therapeutic approaches.
Foodborne pathogens and acid resistance
Lactic acid can influence the membrane lipid composition and acid resistance of Escherichia coli O157:H7, affecting its survival in gastric fluid. This has implications for food safety and infection control.
Dental health and saliva
Lactic acid production in saliva is a factor in oral biology. While not directly a disease, it relates to dental caries and oral microbiome balance.
From lactic acid secretion-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does LDHA knockout reduce lactic acid secretion? | LDHA knockout cell line |
| Does MCT4 overexpression increase lactic acid export? | MCT4 overexpression cell line |
| What is the effect of a point mutation in SLC16A1 on lactate transport? | Point mutation knock-in |
| Can we tag MCT1 to visualize its localization? | Tagged knock-in |
| Does SLC16A11 risk variant affect lactate secretion? | Knock-in of variant |
| Can CRISPR library screening identify new regulators of lactic acid secretion? | CRISPR library screening |
How to Study the lactic acid secretion Process
| Method | What It Measures | Typical Application |
|---|---|---|
| Enzymatic assay | Lactic acid concentration | Quantify secretion in cell culture |
| Biosensor | Real-time lactic acid levels | Sweat monitoring |
| CRISPR knockout | Gene function | Study LDHA in lactic acid secretion |
| RNA-seq | Gene expression | Identify regulators of lactic acid secretion |
| Proteomics | Protein abundance | Detect transporters like MCT4 |
| Metabolomics | Metabolite profiling | Measure lactic acid and related metabolites |
| Microbial fermentation | Lactic acid production | Dairy fermentation |
Metabolic assays
Lactic acid secretion can be measured using enzymatic assays or biosensors. For example, a wristwatch sweat lactic acid monitor has been developed.
Genomic modification
CRISPR-Cas9 can be used to knockout or knock-in genes involved in lactic acid secretion, such as LDHA or SLC16A1, to study their function.
Omics approaches
RNA-seq and proteomics can identify genes and proteins differentially expressed under conditions that alter lactic acid secretion.
Microbiological methods
Lactic acid bacteria can be isolated and characterized from various sources, such as human milk, and their lactic acid secretion can be quantified.
How CRISPR Can Be Used to Study GO:0046722 lactic acid secretion
Knockout
CRISPR knockout of genes like LDHA or SLC16A1 can abolish or reduce lactic acid secretion, helping to establish causality.
Point Mutation
Introducing point mutations in transporters such as SLC16A1 can reveal residues critical for lactic acid transport.
Knock-in
Knock-in of tagged versions of MCT proteins allows visualization and tracking of lactic acid secretion machinery.
Overexpression
Overexpression of MCT4 or LDHA can increase lactic acid secretion, useful for studying its effects on cells and environment.
How EDITGENE Supports lactic acid secretion Research
Researchers studying lactic acid secretion-related genes often need to determine whether a candidate gene is causally involved in the process, and CRISPR-based models are essential for such functional studies.
Contact EDITGENE today to design your custom CRISPR model for lactic acid secretion research.
Frequently Asked Questions About lactic acid secretion
What is lactic acid secretion?
Lactic acid secretion (GO:0046722) is the controlled release of lactic acid by a cell or tissue, as defined by QuickGO.
What genes are involved in lactic acid secretion?
Genes such as LDHA, SLC16A1 (MCT1), and SLC16A3 (MCT4) are involved in lactic acid production and transport.
How is lactic acid secretion measured?
It can be measured using enzymatic assays, biosensors like wristwatch sweat monitors, or by quantifying lactic acid in saliva.
Why is lactic acid secretion important in dairy fermentation?
Lactic acid bacteria secrete lactic acid during fermentation, which is essential for dairy product quality.
Does lactic acid secretion affect skin pH?
Yes, lactic acid secretion contributes to skin pH, and alterations are seen in atopic dermatitis.
Can lactic acid secretion influence pathogens?
Lactic acid can affect the membrane lipids and acid resistance of Escherichia coli O157:H7.
Is lactic acid secretion present in human milk?
Lactic acid bacteria have been isolated from human milk, suggesting a role in infant health.
What is the role of lactic acid secretion in milk fat synthesis?
In cows, intraruminal infusion of lactic acid affects the secretion of component fatty acids of milk fat.
How can CRISPR be used to study lactic acid secretion?
CRISPR can knockout or knock-in genes like LDHA or SLC16A1 to study their function in lactic acid secretion.
What are the synonyms for lactic acid secretion?
The synonym is lactate secretion, as listed in QuickGO.
Conclusion
Lactic acid secretion (GO:0046722) is a fundamental biological process with wide-ranging implications from microbial fermentation to human physiology. Understanding its mechanisms and regulation can lead to advances in dairy science, food safety, and medicine. CRISPR-based models are powerful tools for dissecting the genes involved, and EDITGENE offers comprehensive services to support such research.
References
- 2. STORRY JE et al.. 1965. EFFECT IN THE COW OF INTRARUMINAL INFUSIONS OF VOLATILE FATTY ACIDS AND OF LACTIC ACID ON THE SECRETION OF THE COMPONENT FATTY ACIDS OF THE MILK FAT AND ON THE COMPOSITION OF BLOOD.. Biochem J 96(1):210-7 PMID: 14343134
- 3. Xie Z et al.. 2024. Invited review: Genomic modifications of lactic acid bacteria and their applications in dairy fermentation.. J Dairy Sci 107(11):8749-8764 PMID: 38969005
- 4. Danby SG et al.. 2018. pH in Atopic Dermatitis.. Curr Probl Dermatol 54:95-107 PMID: 30130778
- 5. Yuk HG et al.. 2005. Influence of acetic, citric, and lactic acids on Escherichia coli O157:H7 membrane lipid composition, verotoxin secretion, and acid resistance in simulated gastric fluid.. J Food Prot 68(4):673-9 PMID: 15830655
- 6. Kang W et al.. 2020. Isolation and characterization of lactic acid bacteria from human milk.. J Dairy Sci 103(11):9980-9991 PMID: 32952010
- 7. RAE JJ et al.. 1956. Lactic acid production in saliva.. J Dent Res 35(4):612-4 PMID: 13345939
- 8. Konno S et al.. 2024. Fundamental Study of a Wristwatch Sweat Lactic Acid Monitor.. Biosensors (Basel) 14(4) PMID: 38667180
