SLC19A3 Antibody

What is SLC19A3 and what biological function does it serve?

SLC19A3 (Solute Carrier Family 19 Member 3) is a membrane protein that functions as a high-affinity thiamine transporter, facilitating the uptake of vitamin B1 (thiamine) into cells via a proton anti-port mechanism. This transport is essential for proper cellular metabolism as thiamine serves as a critical cofactor for numerous enzymes . Recent research has revealed that SLC19A3 also mediates H+-dependent pyridoxine (vitamin B6) transport, though it exhibits no folate transport activity . SLC19A3 forms part of a complex with other transporter proteins that collectively maintain cellular thiamine homeostasis .

The protein has a calculated molecular weight of 56 kDa (496 amino acids), though the observed molecular weight in experimental conditions typically ranges between 63-70 kDa, likely due to post-translational modifications . SLC19A3 is also known as Thiamine Transporter 2 (ThTr-2) in scientific literature .

What are the validated applications for SLC19A3 antibodies in research?

SLC19A3 antibodies have been validated for multiple experimental applications as demonstrated in the published scientific literature:

Researchers should note that optimal dilutions are sample-dependent and should be determined empirically for each experimental system . The antibody has been successfully used to detect SLC19A3 in various tissues including mouse liver, skeletal muscle, kidney, human placenta, rat heart, and cell lines such as SH-SY5Y and 3T3-L1 .

What species reactivity has been confirmed for SLC19A3 antibodies?

The reactivity of available SLC19A3 antibodies has been experimentally confirmed in the following species:

What are the recommended protocols for western blot detection of SLC19A3?

For optimal western blot detection of SLC19A3, researchers should consider the following methodological approach based on published protocols:

• Sample preparation: Isolate membranous fractions by ultracentrifugation (e.g., 100,000 × g for 10 min) as described in previous studies .

• Protein resolution: Use 4-12% Bis-Tris minigels for optimal separation of the 63-70 kDa SLC19A3 protein .

• Transfer and blocking: Electroblot onto PVDF membranes and block overnight with appropriate blocking solution (e.g., Odyssey blocking solution) at 4°C .

• Primary antibody incubation: Apply SLC19A3-specific polyclonal antibody at a dilution of 1:500-1:2000, along with a loading control antibody such as β-actin (1:3,000 dilution) .

• Detection: Use appropriate secondary antibodies and detection systems compatible with your laboratory setup .

Researchers have reported successful detection of SLC19A3 protein in various tissues including liver, skeletal muscle, kidney, and placenta using this approach .

How can researchers distinguish between SLC19A2 and SLC19A3 in experimental designs?

Distinguishing between the related transporters SLC19A2 and SLC19A3 is crucial for accurate interpretation of experimental results. The following approaches are recommended:

• Antibody selection: Use polyclonal antibodies specifically raised against peptide regions of SLC19A3 with low homology to SLC19A2 to minimize cross-reactivity. For example, the antibody described in search result was specifically designed to avoid cross-reaction with SLC19A2 .

• Molecular weight differentiation: SLC19A3 exhibits an observed molecular weight of 63-70 kDa, which can help distinguish it from other related transporters on western blots .

• Gene-specific primers: For PCR-based detection, design primers that target unique regions of SLC19A3. Published studies have used specific primers for SLC19A3 quantification as described in previous literature .

• Functional characterization: SLC19A3 and SLC19A2 have different transport characteristics and cellular localization patterns that can be used for functional discrimination .

• Knockout models: Utilize Slc19a2 and Slc19a3 knockout mouse models to definitively study the specific roles of each transporter .

What methods are effective for quantifying SLC19A3 expression in tissue samples?

Several validated methods for quantifying SLC19A3 expression in tissue samples are available to researchers:

• Quantitative real-time PCR (qRT-PCR):

  • RNA isolation using commercial kits (e.g., RotiQuick-Kit)

  • Reverse transcription with appropriate reverse transcriptase (e.g., RevertAid H Minus M-MuLV)

  • Amplification using SYBR Green or similar qPCR mixes

  • Normalization to housekeeping genes such as HPRT

  • Relative quantification using the ΔΔCt method

• Western blot analysis:

  • Membranous fraction isolation

  • SDS-PAGE separation

  • Transfer to nitrocellulose or PVDF membranes

  • Probing with SLC19A3-specific antibodies

  • Normalization to loading controls (β-actin or α-tubulin)

  • Densitometric analysis for semi-quantitative assessment

• Immunofluorescence/Immunohistochemistry:

  • For spatial localization and relative expression levels in tissue sections

  • Can be combined with cell-type specific markers (e.g., NeuN for neurons, GFAP for astrocytes) for co-localization studies

• Genomic copy number analysis:

  • TaqMan Copy Number Assays for detecting genomic alterations

  • Duplex real-time PCR with appropriate reference assays

These methods can be combined for comprehensive expression analysis at both mRNA and protein levels, providing complementary information about SLC19A3 regulation.

How does stress affect SLC19A3 expression, and how can these changes be measured?

Research indicates that SLC19A3 expression is regulated by stress conditions, with important implications for thiamine metabolism. To investigate stress-induced changes:

• Stress induction models:

  • Hypoxic conditions (can be assessed using HIF-1α as a marker)

  • Nutrient deprivation

  • Oxidative stress

  • Disease states (e.g., Huntington's disease)

• Expression analysis:

  • Compare baseline versus stress-induced expression using qRT-PCR

  • Measure protein levels by western blot before and after stress exposure

  • Normalize to appropriate housekeeping genes/proteins that remain stable under the specific stress conditions

• Functional assessment:

  • Measure thiamine uptake using radiolabeled thiamine or fluorescent analogs

  • Correlate uptake changes with SLC19A3 expression levels

  • Assess downstream metabolic effects of altered thiamine transport

Research has shown that normal stress-induced upregulation of SLC19A3 can be impaired in certain disease conditions, suggesting a potential therapeutic target . Quantification of these changes requires careful experimental design with appropriate controls and normalization strategies.

What mutations in SLC19A3 have been identified, and how do they affect protein function?

Several pathogenic mutations in the SLC19A3 gene have been identified through genetic studies, with significant implications for thiamine metabolism and related disorders:

• Recently identified mutations:

  • NM_025243.4:c.1385dupA:pY462X - A homozygous variant resulting in a premature stop codon at position 462, leading to the loss of the C-terminal domain of SLC19A3 protein

  • This C-terminal domain contains phosphorylation sites important for regulation and plays a critical role in signal transduction for conformational changes in the thiamine transport channel

• Functional consequences:

  • Truncation mutations like pY462X result in loss of the C-terminal regulatory domain

  • Missense mutations may affect thiamine binding or transport efficiency

  • Mutations can impair the proton anti-port mechanism essential for thiamine uptake

  • Altered SLC19A3 function leads to cellular thiamine deficiency despite normal serum levels

• Detection methods:

  • Whole-exome sequencing (WES) for comprehensive mutation detection

  • Sanger sequencing for confirmation of specific variants

  • ACMG guideline-based classification of variant pathogenicity

  • 3D protein structural modeling using tools such as PyMol for functional prediction

These mutations are associated with thiamine metabolism dysfunction syndrome 2 (THMD2), also known as biotin- or thiamine-responsive encephalopathy type 2, which can present with severe neurological manifestations if untreated .

How do SLC19A3 knockout mouse models contribute to understanding thiamine transport mechanisms?

SLC19A3 knockout (Slc19a3-/-) mouse models have provided valuable insights into the physiological role of this transporter:

• Functional redundancy:

  • Studies with Slc19a3 knockout mice have demonstrated that both mTHTR-1 (Slc19a2) and mTHTR-2 (Slc19a3) contribute to carrier-mediated thiamine uptake in various tissues, including pancreatic acinar cells

  • This indicates partial functional overlap between these transporters

• Tissue-specific effects:

  • Knockout models allow assessment of SLC19A3 contribution to thiamine transport in specific tissues

  • Western blot analysis using SLC19A3-specific antibodies can confirm the absence of the protein in knockout tissues

  • Comparison with wild-type tissue reveals the relative contribution of SLC19A3 to total thiamine transport

• Compensatory mechanisms:

  • Knockout models reveal potential upregulation of alternative transporters in the absence of SLC19A3

  • These compensatory changes may explain the phenotypic differences between genetic knockouts and disease-causing mutations

• Methodological applications:

  • Tissues from knockout mice serve as excellent negative controls for antibody validation

  • They provide critical tools for assessing the specificity of SLC19A3 antibodies in immunoblotting, immunoprecipitation, and immunohistochemistry applications

These findings highlight the importance of both transporters in maintaining cellular thiamine homeostasis and provide experimental models for studying thiamine-dependent metabolic processes.

What is the relationship between SLC19A3 deficiency and neurological disorders?

SLC19A3 deficiency has been strongly linked to several neurological disorders, particularly those affecting thiamine metabolism:

• Thiamine Metabolism Dysfunction Syndrome 2 (THMD2):

  • Also known as biotin- or thiamine-responsive encephalopathy type 2

  • Characterized by progressive neurological impairment

  • If untreated, can result in severe neurological damage and death

  • Early clinical presentation may resemble infantile Leigh syndrome

• Neuroimaging findings:

  • Bilateral thalamic and basal ganglia lesions

  • Brain atrophy in severe cases

  • These findings reflect the critical role of thiamine in energy metabolism in these highly metabolically active regions

• Huntington's disease connection:

  • Research indicates aberrant transcriptome-polyadenylation leading to SLC19A3 deficiency in Huntington's disease

  • CPEB (cytoplasmic polyadenylation element binding protein) alterations may contribute to this deficiency

  • This represents a potentially treatable aspect of Huntington's disease pathophysiology

• Treatment approaches:

  • Supplementation with thiamine and/or biotin has shown therapeutic benefit

  • Early diagnosis through genetic testing can enable prompt intervention

  • Understanding the exact molecular mechanisms of SLC19A3 dysfunction is critical for developing targeted therapies

The relationship between SLC19A3 and neurological disorders underscores the importance of thiamine transport for proper neuronal function and brain development.

What are the critical factors for optimizing immunoprecipitation protocols with SLC19A3 antibodies?

For successful immunoprecipitation (IP) of SLC19A3 protein, researchers should consider the following critical factors:

• Antibody amount and quality:

  • Recommended usage: 0.5-4.0 μg antibody for 1.0-3.0 mg of total protein lysate

  • Use affinity-purified antibodies for higher specificity and lower background

  • Validate antibody specificity using western blot before IP experiments

• Sample preparation:

  • Effective lysis buffers should contain appropriate detergents for membrane protein solubilization

  • Optimization of lysis conditions is critical as SLC19A3 is a multi-pass membrane protein

  • Pre-clearing lysates can reduce non-specific binding

• Validated positive controls:

  • Mouse liver tissue has been validated for successful IP of SLC19A3

  • Include positive tissue controls when optimizing new experimental conditions

• Detection methods:

  • Western blot analysis of immunoprecipitated material

  • Appropriate negative controls (IgG or non-expressing tissues)

  • Consider mass spectrometry for identification of interaction partners

• Co-immunoprecipitation considerations:

  • Milder lysis conditions may be needed to preserve protein-protein interactions

  • Cross-linking approaches may stabilize transient interactions

  • Consider native versus denatured IP depending on experimental goals

Following established protocols while optimizing for specific experimental conditions will maximize the chances of successful SLC19A3 immunoprecipitation .

How should researchers approach validation of SLC19A3 antibodies for new experimental applications?

A systematic approach to validating SLC19A3 antibodies for new experimental applications should include:

• Initial specificity assessment:

  • Western blot analysis using tissues known to express SLC19A3 (liver, kidney, skeletal muscle, placenta)

  • Verification of the expected molecular weight band (63-70 kDa)

  • Testing multiple positive and negative control tissues

• Application-specific validation:

  • For immunofluorescence: Include appropriate negative controls and blocking peptides

  • For flow cytometry: Compare with isotype controls and known expression patterns

  • For IHC: Use antigen retrieval optimization and gradient dilution series

• Genetic validation approaches:

  • Testing in SLC19A3 knockout models as negative controls

  • Testing in overexpression systems as positive controls

  • siRNA knockdown to confirm specificity of detection

• Cross-reactivity assessment:

  • Evaluate potential cross-reactivity with related transporters, particularly SLC19A2

  • Use antibodies raised against regions with low homology between related proteins

• Reproducibility testing:

  • Test batch-to-batch consistency if using different antibody lots

  • Ensure consistent results across different experimental conditions

  • Document optimization parameters for future reference

Antibody validation is a critical step that ensures reliable and reproducible research results, particularly for challenging membrane proteins like SLC19A3.