CTPA1 Antibody

What is CTPS1 and what role does it play in cellular metabolism?

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 .

What types of CTPS1 antibodies are commonly available for research?

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 402-591 of human CTPS1

• Antibodies targeting amino acids 50-400 of human CTPS1

• Antibodies targeting amino acids 500 to C-terminus of human CTPS1

• Antibodies targeting the sequence PYFGLLLASVGRLSHYLQKGCRLSPRDTYSDRSGSSSPDSEITELKFPSINHD

What species reactivity can I expect from CTPS1 antibodies?

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 .

What applications are CTPS1 antibodies validated for?

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:

What are the optimal conditions for using CTPS1 antibodies in Western blotting?

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

What are the key considerations for immunohistochemistry with CTPS1 antibodies?

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

How can CTPS1 antibodies be used to study immune cell function?

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

What technical challenges might arise when using CTPS1 antibodies and how can they be addressed?

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

How can CTPS1 antibodies be used in the context of cancer research?

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)

What are the considerations when using CTPS1 antibodies in studies of enzyme function?

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

How do CTPS1 and CPT1A antibodies differ, and how can I ensure I'm using the correct one?

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

What experimental controls should be included when using CTPS1 antibodies?

Proper controls are essential for antibody-based experiments. For CTPS1 antibodies, consider:

• Positive controls:

  • Cell lines with known CTPS1 expression (e.g., HeLa, HepG2, HEK-293T cells)

  • Tissues with high proliferation rates (e.g., intestinal epithelium, thymic tissue)

  • Activated lymphocytes, which upregulate CTPS1 expression

• 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)

How can I validate CTPS1 antibody specificity in my experimental system?

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

What are the key differences in experimental design when studying CTPS1 versus CTPS2?

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:

  • Leverage tissue-specific expression patterns (CTPS1 is crucial in immune cells and embryonic development)

  • Study contexts where one isoform is known to be predominant (e.g., activated lymphocytes for CTPS1)

• Functional studies:

  • CTPS1 deletion is embryonic-lethal, while CTPS2 deletion is not

  • Both CTPS1 and CTPS2 are required for T cell proliferation following TCR stimulation

  • Design knockout/knockdown experiments targeting each isoform specifically

How are CTPS1 antibodies being used to study autoimmune diseases?

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

What are the implications of CTPS1 filament formation (cytoophidia) for antibody-based detection methods?

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:

  • Use live-cell imaging approaches when possible

  • Compare multiple antibodies targeting different epitopes

  • Consider co-staining for other cytoophidia components (e.g., IMPDH)

How might CTPS1 antibodies contribute to the development of targeted therapies?

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