CTPS1 Antibody targets Cytidine Triphosphate Synthase 1 (CTPS1), an enzyme critical for de novo synthesis of cytidine triphosphate (CTP), a nucleotide essential for DNA/RNA biosynthesis and phospholipid metabolism . This antibody is widely used to study CTPS1's role in cellular proliferation, immune responses, and diseases such as immunodeficiency and autoimmunity .
Immune Cell Proliferation: CTPS1 is indispensable for T and B cell expansion post-antigen activation. Deficiency leads to impaired lymphocyte proliferation and immunodeficiency .
Embryonic Development: In mice, Ctps1 deletion is embryonic-lethal, highlighting its role in high-proliferation tissues (e.g., intestinal epithelium, erythroid cells) .
Therapeutic Target: CTPS1 inhibitors (e.g., Stp-2) rescue autoimmune phenotypes in murine models, suggesting clinical potential .
Human Studies: CTPS1-deficient patients exhibit combined immunodeficiency with susceptibility to viral infections (e.g., Epstein-Barr virus). T and B cells show impaired proliferation but retain effector functions like cytokine production .
Mouse Models: Conditional Ctps1 knockout mice display:
Autoimmunity: Ctps1 inactivation in T cells rescues Foxp3-deficient mice from fatal autoimmunity and reduces experimental autoimmune encephalomyelitis severity .
Clinical Trials: A selective CTPS1 inhibitor (NCT05463263) is under evaluation for T/B cell lymphoma .
Western Blotting: Detects endogenous CTPS1 at ~78 kDa in human cell lysates .
Immunofluorescence: Used to localize CTPS1 in whole-mount embryos and proliferating lymphocytes .
Functional Studies: Validates CTPS1 knockdown/out in proliferation assays (e.g., TCR-stimulated T cells) .
CTPS1 (CTP synthase 1) is a key enzyme that catalyzes the ATP-dependent amination of UTP to CTP with either L-glutamine or ammonia as a nitrogen source . This process is essential for the de novo synthesis of CTP, which is a critical building block for DNA, RNA, and phospholipids . CTPS1 activity is particularly important in cells with high proliferation rates, as it generates nucleotides needed for DNA and RNA synthesis during cell division and growth .
Most commercially available CTPS1 antibodies are polyclonal antibodies raised in rabbits . These antibodies typically target specific sequences or regions of the CTPS1 protein. For example:
Antibodies targeting amino acids 500 to C-terminus of human CTPS1
Antibodies targeting the sequence PYFGLLLASVGRLSHYLQKGCRLSPRDTYSDRSGSSSPDSEITELKFPSINHD
Most CTPS1 antibodies are developed to target human CTPS1, but many also show cross-reactivity with mouse samples due to the high conservation of the protein between species (90% homology/identity) . It's important to check each antibody's datasheet for confirmed species reactivity, as this varies between products .
Antibody | Species Reactivity | Source |
---|---|---|
CAB3817 | Human, Mouse | Rabbit polyclonal |
ab235000 | Human | Rabbit polyclonal |
#98287 | Human | Rabbit polyclonal |
CTPS1 antibodies are validated for multiple research techniques, with Western blotting being the most common application . The table below summarizes the applications for which different CTPS1 antibodies are validated:
For Western blotting applications, CTPS1 antibodies typically detect a protein of approximately 67-78 kDa . Recommended dilutions vary by manufacturer but generally range from 1:500 to 1:6000 . To optimize Western blotting with CTPS1 antibodies:
Use an appropriate blocking buffer (typically 5% non-fat milk or BSA in TBST)
Incubate with primary antibody at the recommended dilution (typically 1:1000 for most CTPS1 antibodies)
Wash thoroughly to minimize background
Expected molecular weight is around 67-78 kDa depending on the specific antibody and the cell/tissue type
When performing immunohistochemistry with CTPS1 antibodies, consider the following:
Antigen retrieval methods: For optimal results, use TE buffer at pH 9.0 or citrate buffer at pH 6.0
Recommended antibody dilutions range from 1:50 to 1:2000 depending on the specific antibody
CTPS1 expression has been successfully detected in various human tissues, particularly in tissues with high cell proliferation rates
For IHC-P applications, paraffin-embedded human tissues have been successfully stained with dilutions around 1:100-1:200
CTPS1 plays a crucial role in the proliferation of activated lymphocytes and therefore in immunity . Research shows that:
CTPS1 expression increases in T cells upon T-cell receptor activation
Deletion of Ctps1 in T cells or treatment with a CTPS1 inhibitor rescued Foxp3-deficient mice from fatal systemic autoimmunity
Tissues with high proliferation and renewal rates (including activated B and T lymphocytes, and memory T cells) strongly rely on CTPS1 for their maintenance and growth
For studying immune cell function, researchers can use CTPS1 antibodies to:
Track CTPS1 expression levels in lymphocytes before and after activation
Correlate CTPS1 expression with proliferation rates of immune cells
Investigate the effects of CTPS1 inhibitors on immune responses
When working with CTPS1 antibodies, researchers might encounter several technical challenges:
Cross-reactivity with CTPS2: Due to the 75% homology between CTPS1 and CTPS2 , some antibodies might cross-react. To address this:
Verify the epitope region of your antibody doesn't overlap with homologous regions of CTPS2
Use CTPS1-knockout or CTPS1-depleted cells as negative controls
Perform validation using siRNA knockdown of CTPS1
Variable expression levels: CTPS1 expression is highly regulated and varies across cell types and activation states . To account for this:
Include appropriate positive controls (e.g., activated lymphocytes)
Consider cell-specific optimization of antibody concentration
Use loading controls and quantification methods appropriate for your experimental system
Detection in fixed tissues: Some epitopes may be sensitive to fixation methods. To overcome this:
Test different antigen retrieval methods (as mentioned in section 2.3)
Consider using fresh frozen samples for certain applications
Validate antibody performance on your specific tissue/fixation conditions
Dysregulation of CTPS1 has been implicated in various diseases, including cancer . For cancer research applications:
CTPS1 antibodies can be used to assess protein expression levels in different cancer types and correlate with disease progression
Immunohistochemistry with CTPS1 antibodies can help identify cellular localization of CTPS1 in tumor samples
Western blotting can quantify changes in CTPS1 expression following treatment with anti-cancer agents
Cancer research has utilized CTPS1 antibodies in cell lines such as HeLa (cervical cancer) and HepG2 (liver cancer)
When studying CTPS1 enzyme function:
Enzyme activity vs. expression: CTPS antibodies detect protein levels but don't directly measure enzyme activity. Consider complementing antibody-based detection with functional assays for CTP production.
Oligomerization state: CTPS1 can form filamentous structures called cytoophidia under certain metabolic conditions . When interpreting immunofluorescence results:
Pay attention to subcellular localization patterns
Consider metabolic state of cells when analyzing CTPS1 distribution
Use confocal microscopy to distinguish between diffuse and filamentous forms
Post-translational modifications: CTPS1 activity is regulated by phosphorylation and other modifications that may affect antibody recognition:
Use phospho-specific antibodies if studying CTPS1 regulation
Consider how experimental treatments might affect CTPS1 modifications
CTPS1 (CTP synthase 1) and CPT1A (carnitine palmitoyltransferase 1A) are distinct proteins with different functions, despite their similar acronyms:
To ensure you're using the correct antibody:
Verify the target protein name and gene ID in product documentation
Confirm the expected molecular weight on Western blots
Check immunogen sequence information to ensure specificity
Use positive controls with known expression of either CTPS1 or CPT1A
Proper controls are essential for antibody-based experiments. For CTPS1 antibodies, consider:
Positive controls:
Negative controls:
CTPS1 knockout or knockdown cells (via CRISPR-Cas9 or siRNA)
Secondary antibody-only controls to assess non-specific binding
Blocking peptide competition assays to confirm specificity
Loading controls for Western blotting:
Housekeeping proteins (β-actin, GAPDH, tubulin)
Total protein staining methods (Ponceau S, REVERT)
To validate CTPS1 antibody specificity:
Genetic approaches:
Generate CTPS1-knockout or knockdown models
Compare antibody signal between wild-type and CTPS1-depleted samples
Perform rescue experiments by re-expressing CTPS1
Biochemical approaches:
Use blocking peptides corresponding to the immunogen
Compare multiple antibodies targeting different epitopes of CTPS1
Perform immunoprecipitation followed by mass spectrometry
Experimental manipulations:
Induce CTPS1 expression (e.g., T cell activation) and confirm increased signal
Use CTPS1 inhibitors and confirm decreased functional outcomes
Compare tissues with known differential expression of CTPS1
When designing experiments to distinguish between CTPS1 and CTPS2:
Antibody selection:
Choose antibodies targeting non-homologous regions of CTPS1
Verify antibody specificity against recombinant CTPS1 and CTPS2 proteins
Biological contexts:
Functional studies:
Recent research has shown that CTPS1 plays a critical role in autoimmune disease pathogenesis:
Deletion of Ctps1 in T cells or treatment with a CTPS1 inhibitor rescued Foxp3-deficient mice from fatal systemic autoimmunity
CTPS1 inhibition reduced the severity of experimental autoimmune encephalomyelitis
CTPS1 antibodies can be used to:
Monitor CTPS1 expression in patient samples
Evaluate the efficacy of CTPS1 inhibitors in preclinical models
Study the relationship between CTPS1 activity and autoimmune disease progression
CTPS1 can assemble into filamentous structures called cytoophidia under certain metabolic conditions . This has important implications for antibody-based detection:
Epitope accessibility may differ between soluble and filamentous forms of CTPS1
Some antibodies may preferentially recognize one conformational state
Fixation methods may affect filament preservation and antibody recognition
When studying cytoophidia:
CTPS1 antibodies are valuable tools in the development pipeline for targeted therapies:
Target validation:
Confirm CTPS1 expression in disease-relevant tissues
Evaluate correlation between CTPS1 levels and disease parameters
Study mechanisms of CTPS1 regulation in pathological states
Compound screening:
Assess effects of candidate drugs on CTPS1 expression and localization
Monitor CTPS1 inhibition as a pharmacodynamic marker
Evaluate on-target versus off-target effects of CTPS1-directed therapies
Biomarker development:
Explore CTPS1 as a potential biomarker in conditions with aberrant proliferation
Develop immunoassays to monitor CTPS1 levels in clinical samples
Correlate CTPS1 expression with response to therapy