ATP2A1 Antibody

What is ATP2A1 and what is its functional significance in cellular processes?

ATP2A1, encoded by the ATP2A1 gene in humans, is a 1001-amino acid protein belonging to the Cation transport ATPase (P-type) family, Type IIA subfamily. This integral membrane protein functions as a calcium pump that transports Ca²⁺ from the cytosol to the sarcoplasmic/endoplasmic reticulum (SR/ER) lumen against a large concentration gradient, using ATP hydrolysis to power this process. ATP2A1 is predominantly expressed in fast-twitch skeletal muscle where it plays a critical role in muscle excitation-contraction coupling by removing calcium from the cytosol after contraction, allowing muscles to relax .

Recent research has revealed additional functions of ATP2A1, including unexpected roles in SARS-CoV-2 infection. During viral infection, a modulation of ATP2A1 expression occurs through the PI3K/Akt signaling pathway and inhibition of FOXO3 transcriptional activity. Reduced ATP2A1 expression appears to promote SARS-CoV-2 replication by increasing intracellular Ca²⁺ levels .

What are the key considerations when selecting ATP2A1 antibodies for research applications?

When selecting ATP2A1 antibodies, researchers should consider multiple factors:

• Antibody format: Choose between monoclonal and polyclonal antibodies based on your experimental needs:

  • Monoclonal antibodies (like Cell Signaling Technology's ATP2A1/SERCA1 D54G12) offer higher specificity and consistency between batches, making them ideal for quantitative applications

  • Polyclonal antibodies (such as Proteintech's 22361-1-AP) recognize multiple epitopes, potentially providing higher sensitivity for detecting low-abundance targets

• Target epitope: Consider which region of ATP2A1 to target based on your research question:

  • N-terminal targeting antibodies (e.g., ABIN3030066) are useful for detecting full-length protein

  • C-terminal antibodies may help detect specific isoforms or truncated proteins

  • For structural studies, select epitopes that don't interfere with protein function

• Validated applications: Verify that the antibody has been validated for your specific application:

  • For Western blotting: Cell Signaling's antibodies are typically used at 1:1000 dilution

  • For IHC: Proteintech's ATP2A1 antibody is recommended at 1:50-1:500 dilution

  • For immunoprecipitation: 0.5-4.0 μg for 1.0-3.0 mg of total protein lysate

• Species reactivity: Confirm compatibility with your experimental model:

  • Many ATP2A1 antibodies react with human, mouse, and rat samples

  • Check sequence homology if working with other species

How can researchers validate the specificity of ATP2A1 antibodies?

Validation of ATP2A1 antibodies is essential for reliable results. Multiple complementary approaches should be employed:

• Positive and negative tissue controls:

  • Use skeletal muscle tissue (high ATP2A1 expression) as a positive control

  • Include non-muscle tissues (minimal expression) as negative controls

  • In Western blots, expect a distinct band at approximately 116 kDa in skeletal muscle samples

• Molecular weight verification:

  • The calculated molecular weight is 110 kDa, but ATP2A1 typically appears at 116 kDa on Western blots due to post-translational modifications

  • Verify that the observed band matches the expected size

• Peptide competition assays:

  • Pre-incubate the antibody with its immunizing peptide

  • This should eliminate or significantly reduce specific signals

  • Persistent signal may indicate non-specific binding

• Knockout/knockdown validation:

  • If available, test the antibody in ATP2A1 knockout or knockdown systems

  • Absence or reduction of signal confirms specificity

• Multiple antibody comparison:

  • Compare results using antibodies targeting different epitopes of ATP2A1

  • Similar patterns increase confidence in specificity

What are the optimal protocols for using ATP2A1 antibodies in Western blot analysis?

Successful Western blotting with ATP2A1 antibodies requires careful optimization:

Sample preparation:

• Use fresh skeletal muscle tissue when possible

• Homogenize in RIPA buffer containing protease inhibitors

• For cell lines, use lysis buffer containing 1% NP-40 or Triton X-100, 150 mM NaCl, and 50 mM Tris-HCl (pH 7.5)

Electrophoresis and transfer:

• Use 8-10% polyacrylamide gels due to ATP2A1's large size (116 kDa)

• Load 10-30 μg of total protein per lane

• Transfer to PVDF membrane using wet transfer (100V for 2 hours or 30V overnight at 4°C)

Antibody incubation:

• Block with 5% non-fat dry milk in TBST for 1 hour at room temperature

• Dilute primary antibody according to manufacturer recommendations:

  • Cell Signaling Technology ATP2A1/SERCA1 antibodies: 1:1000

  • Proteintech ATP2A1 antibody: 1:20000-1:100000

• Incubate overnight at 4°C with gentle rocking

• Wash 3-5 times with TBST, 5 minutes each

• Incubate with appropriate HRP-conjugated secondary antibody (1:5000-1:10000)

Expected results:

• A distinct band at approximately 116 kDa in skeletal muscle samples

• Low or no signal in non-muscle tissues

• For suspected splice variants or truncations, additional bands may be observed

How should tissue samples be prepared for immunohistochemistry with ATP2A1 antibodies?

Optimal immunohistochemistry protocols for ATP2A1 include:

Tissue processing:

• Fix tissues in 10% neutral buffered formalin for 24-48 hours

• Process and embed in paraffin; section at 4-6 μm thickness

• For frozen sections, embed in OCT compound and section at 8-10 μm

Antigen retrieval:

• Heat-induced epitope retrieval is typically required

• Recommended methods:

  • Boil paraffin sections in 10 mM citrate buffer (pH 6.0) for 20 minutes

  • Alternatively, use TE buffer (pH 9.0) for antigen retrieval

• Allow slides to cool to room temperature (approximately 20 minutes)

Antibody application:

• Block endogenous peroxidase with 0.3% H₂O₂ in methanol for 15 minutes

• Block non-specific binding with 5-10% normal serum

• Dilute primary ATP2A1 antibody according to manufacturer recommendations:

  • For IHC applications, typical dilutions range from 1:50 to 1:500

• Incubate overnight at 4°C in a humidified chamber

• Apply appropriate detection system (ABC or polymer-based)

• Develop with DAB substrate and counterstain with hematoxylin

Controls:

• Include positive control (skeletal muscle tissue)

• Include negative control (omission of primary antibody)

• ATP2A1 staining should localize to the sarcoplasmic reticulum in muscle fibers

What advanced techniques can be used to study ATP2A1 protein-protein interactions?

Several sophisticated techniques can elucidate ATP2A1's interactome:

Immunoprecipitation-based approaches:

• Co-immunoprecipitation (Co-IP):

  • Use ATP2A1 antibodies to pull down protein complexes

  • For membrane proteins like ATP2A1, use mild detergents (digitonin, CHAPS)

  • Proteintech's ATP2A1 antibody has been validated for IP using 0.5-4.0 μg antibody for 1.0-3.0 mg of total protein lysate

  • Identify partners by Western blot or mass spectrometry

• Proximity-dependent biotinylation:

  • BioID or APEX2: Fuse ATP2A1 with a biotin ligase or engineered peroxidase

  • Identifies proteins in close proximity to ATP2A1 in living cells

  • Valuable for capturing transient interactions

Microscopy-based methods:

• Förster Resonance Energy Transfer (FRET):

  • Tag ATP2A1 and potential interacting proteins with compatible fluorophores

  • Measure energy transfer as indicator of protein proximity

  • Enables study of dynamic interactions in living cells

• Proximity Ligation Assay (PLA):

  • Use primary antibodies against ATP2A1 and potential interacting protein

  • Secondary antibodies with conjugated oligonucleotides enable signal amplification

  • Provides spatial information about interactions in situ

Biochemical approaches:

• Crosslinking Mass Spectrometry (XL-MS):

  • Treat samples with chemical crosslinkers

  • Identify crosslinked peptides by mass spectrometry

  • Provides structural constraints for protein interactions

Key considerations:

• Preserve the native membrane environment whenever possible

• Include positive controls (known interactors)

• Validate interactions using multiple orthogonal techniques

• Consider the dynamic nature of calcium-dependent interactions

How can ATP2A1 antibodies be used to study Brody myopathy?

Brody myopathy is an autosomal recessive muscle disorder caused by mutations in the ATP2A1 gene, characterized by impaired muscle relaxation during exercise. ATP2A1 antibodies are invaluable tools for studying this condition:

Diagnostic applications:

• Immunohistochemistry with ATP2A1 antibodies can assess protein expression in muscle biopsies

• Western blotting can detect truncated proteins or altered expression levels

• Expected findings include reduced or absent ATP2A1 staining or abnormal subcellular distribution

Mutation-specific analysis:

• Different ATP2A1 mutations affect protein expression, stability, or localization differently

• Immunofluorescence can reveal changes in subcellular distribution

• Immunoprecipitation followed by mass spectrometry can identify altered protein interactions

Methodological approaches:

• Quantitative immunohistochemistry:

  • Use digital image analysis to quantify ATP2A1 staining intensity

  • Compare between patient and control samples

  • Correlate with clinical severity

• Fiber type-specific analysis:

  • Co-stain with fiber type markers to assess fiber-specific alterations

  • Combine with calcium indicators to correlate ATP2A1 expression with calcium handling

• Therapeutic monitoring:

  • Assess restoration of ATP2A1 expression in experimental therapies

  • Monitor compensatory expression of other SERCA isoforms

  • Evaluate efficacy of calcium channel modulators

Research has shown that mutations in ATP2A1 cause both classic Brody myopathy and expanded phenotypes that may include clinical myotonia, highlighting the importance of ATP2A1 genetic testing in patients with unexplained muscle disorders .

What is the emerging role of ATP2A1 in SARS-CoV-2 infection pathogenesis?

Recent studies have revealed an unexpected role for ATP2A1 in SARS-CoV-2 infection:

Expression changes during infection:

• ATP2A1 expression is downregulated during SARS-CoV-2 infection (after 48 hours)

• Reduced ATP2A1 levels were observed in lungs from COVID-19 autopsy specimens

• This modulation involves PI3K/Akt signaling and inhibition of FOXO3 transcriptional activity

Functional consequences:

• Downregulation of ATP2A1 promotes SARS-CoV-2 replication by increasing intracellular Ca²⁺ levels

• This contributes to calcium dysregulation observed in infected cells

• ATP2A1 and ATP2A2 showed distinct changes across the lungs of COVID-19 patients

Genetic associations:

• A rare intronic homozygous polymorphism (rs111337717, T>C) in the ATP2B1 locus was positively associated with COVID-19 severity

• This variant has a global frequency of 0.038187

• The finding suggests genetic variants affecting calcium homeostasis may influence COVID-19 susceptibility

Therapeutic implications:

• A caloxin-derivative compound (PI-7) was identified that:

  • Promotes ATP2B1 activity by reducing intracellular Ca²⁺ levels

  • Enhances ATP2B1 and ATP2A1 mRNA and protein levels via FOXO3

  • Impairs SARS-CoV-2 infection and propagation

  • Prevents release of inflammatory cytokines

These findings highlight calcium regulatory proteins as potential therapeutic targets for COVID-19 treatment.

How can researchers investigate post-translational modifications of ATP2A1?

Post-translational modifications (PTMs) of ATP2A1 significantly influence its function and can be studied using specialized approaches:

Phosphorylation analysis:

• Phospho-specific antibodies:

  • Use antibodies recognizing phosphorylated residues on ATP2A1

  • Western blotting to detect changes in phosphorylation under different conditions

  • Immunoprecipitate ATP2A1 followed by phospho-specific antibody detection

• Phosphorylation site mapping:

  • Immunoprecipitate ATP2A1 using validated antibodies

  • Analyze by mass spectrometry to identify phosphorylation sites

  • Compare profiles between normal and disease states

Oxidative modifications:

• Redox proteomics:

  • Derivatize oxidized residues (carbonylation, S-nitrosylation)

  • Immunoprecipitate ATP2A1 and detect modifications

  • Use reducing/non-reducing conditions to assess disulfide formation

SUMOylation and ubiquitination:

• Sequential immunoprecipitation:

  • First immunoprecipitate with ATP2A1 antibodies

  • Then probe for ubiquitin or SUMO modifications

  • Alternatively, immunoprecipitate with ubiquitin/SUMO antibodies and probe for ATP2A1

Methodological considerations:

• Preservation of PTMs:

  • Include phosphatase inhibitors for phosphorylation studies

  • Add deubiquitinase inhibitors for ubiquitination analysis

  • Use mild lysis conditions to maintain intact modifications

• Functional validation:

  • Correlate PTM changes with calcium transport activity

  • Use site-directed mutagenesis to confirm functional significance

  • Develop systems to monitor real-time changes in PTMs and function

What techniques can measure ATP2A1 function in calcium homeostasis at the subcellular level?

Investigating ATP2A1's role in calcium homeostasis requires sophisticated techniques:

Live-cell calcium imaging:

• Genetically encoded calcium indicators (GECIs):

  • Target indicators to specific compartments (cytosol, SR/ER)

  • Combine with ATP2A1-fluorescent protein fusions

  • Monitor calcium dynamics during contraction-relaxation cycles

• Organelle-specific calcium indicators:

  • Use compartment-specific dyes (Fluo-4 for cytosolic, Mag-Fluo-4 for SR/ER)

  • Combine with immunofluorescence to correlate ATP2A1 expression with calcium handling

  • Perform ratio-based measurements for quantitative determination

ATP2A1 localization:

• CRISPR knock-in labeling:

  • Tag endogenous ATP2A1 with fluorescent proteins

  • Maintain natural expression levels and regulation

  • Monitor dynamic redistribution during calcium signaling

• Super-resolution microscopy:

  • Apply STED or PALM techniques to resolve ATP2A1 distribution

  • Visualize relationship to other SR/ER proteins

  • Correlate with calcium microdomain data

Functional activity measurements:

• Microsomes and vesicle preparations:

  • Isolate SR/ER vesicles from muscle tissue

  • Measure ATP2A1-dependent calcium uptake

  • Assess effects of disease mutations or post-translational modifications

• Patch-clamp electrophysiology:

  • Directly measure calcium currents

  • Assess ATP2A1 activity at the single-channel level

  • Investigate effects of regulatory proteins

Integrated approaches:

• Simultaneously measure ATP2A1 localization, calcium levels, and membrane potential

• Correlate with structural data from super-resolution microscopy

• Develop comprehensive models of ATP2A1 function in calcium homeostasis

How can researchers design experiments to study ATP2A1 expression changes in disease models?

Designing rigorous experiments to study ATP2A1 in disease requires careful planning:

Experimental design considerations:

• Model selection:

  • Choose appropriate disease models (patient samples, animal models, cell culture)

  • For Brody myopathy, patient biopsies or gene-edited cells/animals

  • For COVID-19 studies, SARS-CoV-2 infected cells or patient samples

• Temporal dynamics:

  • Include time course analyses to capture expression changes

  • ATP2A1 downregulation during SARS-CoV-2 infection occurs after 48 hours, not during early infection

  • Monitor changes during disease progression or in response to interventions

• Comprehensive profiling:

  • Assess multiple calcium handling proteins simultaneously

  • Include other SERCA isoforms (ATP2A2, ATP2A3) and PMCA pumps (ATP2B1-4)

  • Public datasets show distinct changes in these proteins in COVID-19 patients

Quantification approaches:

• Transcript analysis:

  • qRT-PCR for targeted analysis

  • RNA-seq for comprehensive profiling

  • Single-cell sequencing to assess cell type-specific changes

• Protein quantification:

  • Western blot with appropriate loading controls

  • Quantitative immunohistochemistry with digital image analysis

  • Proteomics approaches for unbiased profiling

Validation strategies:

• Multiple techniques:

  • Confirm findings using orthogonal methods

  • Verify transcript changes translate to protein level changes

  • Correlate with functional calcium handling assays

• Statistical considerations:

  • Ensure adequate sample sizes based on power calculations

  • Account for biological variability

  • Use appropriate statistical tests for data analysis

Functional correlation:

• Connect expression changes to physiological outcomes

• In muscle disorders, correlate with contractile properties

• In infectious diseases, relate to viral replication metrics

What are the most common issues when using ATP2A1 antibodies and how can they be resolved?

Researchers may encounter several challenges when working with ATP2A1 antibodies:

Western blotting issues:

Immunohistochemistry challenges:

Immunoprecipitation issues:

How can researchers optimize ATP2A1 antibody conditions for novel experimental systems?

When adapting ATP2A1 antibodies to new experimental systems, systematic optimization is essential:

Antibody selection strategy:

• Literature review:

  • Identify antibodies previously validated in similar systems

  • Review performance across different applications

• Epitope analysis:

  • Check sequence conservation of the target epitope in your experimental system

  • For non-mammalian models, compare sequence homology in the target region

• Preliminary testing:

  • Perform small-scale pilot experiments with multiple antibodies

  • Compare monoclonal and polyclonal options if available

Systematic optimization protocol for Western blotting:

• Antibody titration:

  • Test a dilution series (e.g., 1:500, 1:1000, 1:5000, 1:10000)

  • Assess signal-to-noise ratio at each concentration

  • For ATP2A1, start with manufacturer recommendations (1:1000 for Cell Signaling , 1:20000-1:100000 for Proteintech )

• Incubation conditions:

  • Compare room temperature (1-2 hours) vs. 4°C overnight incubation

  • Optimize blocking reagent (BSA vs. non-fat milk)

  • Adjust washing stringency and duration

• Detection system optimization:

  • Compare standard ECL vs. high-sensitivity detection systems

  • For low abundance targets, consider signal amplification methods

Immunohistochemistry optimization grid:

• Antigen retrieval matrix:

  • Test multiple methods: heat-induced (citrate pH 6.0, EDTA pH 8.0, TE pH 9.0)

  • Vary retrieval duration (10, 20, 30 minutes)

• Antibody concentration gradient:

  • Create a dilution series (1:50, 1:100, 1:200, 1:500)

  • Include positive control tissue (skeletal muscle) at each dilution

  • Evaluate specific signal vs. background

• Incubation optimization:

  • Compare different temperatures and durations

  • Test various detection systems (ABC vs. polymer-based)

Validation in novel systems:

• Knockout/knockdown controls:

  • Generate CRISPR knockout or siRNA knockdown samples

  • Confirm antibody specificity in the new system

• Heterologous expression:

  • Overexpress tagged ATP2A1 as a positive control

  • Compare antibody staining with tag-specific antibodies

• Cross-species validation:

  • If working with non-mammalian models, confirm cross-reactivity

  • Compare with species-specific antibodies if available