ATF2 (Ab-472) Antibody

What is ATF2 and what cellular functions does it regulate?

ATF2 (Activating Transcription Factor 2) is a member of the leucine zipper family of DNA binding proteins that binds to the cAMP-responsive element (CRE), an octameric palindrome. This protein can form homodimers or heterodimers with c-Jun and stimulates CRE-dependent transcription. Importantly, ATF2 also functions as a histone acetyltransferase (HAT) that specifically acetylates histones H2B and H4 in vitro, suggesting it may represent a class of sequence-specific factors that activate transcription through direct effects on chromatin components .

ATF2 participates in multiple cellular processes including:

• Regulation of amino acid-dependent gene transcription

• Inflammatory responses and cytokine production

• Stress response signaling

• Cell adhesion molecule expression

• Potential roles in neuropathic pain maintenance

What are the specifications of the ATF2 (Ab-472) Antibody?

The ATF2 (Ab-472) Antibody is a rabbit polyclonal antibody specifically targeting the region around the phosphorylation site of serine 472 (A-L-S(p)-Q-I) in human ATF2. Key specifications include:

This antibody detects endogenous levels of total ATF2 protein .

What is the recommended protocol for using ATF2 (Ab-472) Antibody in Western blot analysis?

For optimal Western blot results with ATF2 (Ab-472) Antibody:

• Prepare tissue/cell lysates in ice-cold lysis buffer (150 mM NaCl, 50 mM Tris-HCl, 1 mM EDTA, pH 7.4) with protease inhibitors (2 mM PMSF, 6.8 µg/ml aprotinin, 4 µg/ml leupeptin, 4 µg/ml pepstatin A) and 0.1% Triton X-100 .

• Centrifuge homogenates at 14,000 rpm for 10 minutes to remove cellular debris .

• Determine protein concentration using Bradford's method .

• Use recommended dilution range of 1:500-1:3000 for Western blot applications .

• The antibody has been successfully tested on multiple cell lines including JK cells, HeLa cells, and 293 cells .

How does ATF2 phosphorylation at different sites affect its function in transcriptional regulation?

ATF2 activation through phosphorylation occurs via multiple pathways that influence its transcriptional regulatory functions:

• ATF2 can be activated through two alternative Ras-coupled pathways:

  • The Raf-MEK-ERK pathway phosphorylates threonine 71

  • The Ral-RalGDS-Src-p38 pathway phosphorylates threonine 69

• In growth factor-activated cells, phosphorylation patterns show specific impacts:

  • p38 and JNK-mediated phosphorylation at Thr71 or Thr69+71 cannot fully account for observed ATF2 activation

  • ERK-mediated phosphorylation of Thr69+71 alone cannot efficiently activate ATF2

• Serine 472 phosphorylation appears to be functionally distinct from the well-characterized Thr69/71 phosphorylation, suggesting specialized regulatory mechanisms .

Research has demonstrated that phosphorylation of ATF2 bound to the CHOP AARE (amino acid response element) precedes histone acetylation and CHOP mRNA increase in response to amino acid starvation. Specifically, phosphorylation of ATF2 on threonine 71 was detectable 30 minutes after leucine removal and reached maximum levels within 2 hours .

What role does ATF2 play in inflammation and how can ATF2 (Ab-472) Antibody be used to study inflammatory processes?

ATF2 has significant impacts on inflammatory processes, with research showing both pro-inflammatory and anti-inflammatory roles depending on context:

• Activating roles in inflammation:

  • ATF2 complexes stimulate transcription of cell adhesion molecules (CAMs), including selectins and VCAM-1

  • In ATF2-deficient mice, induction of E-selectin, P-selectin, and VCAM-1 following LPS injection was significantly reduced

  • Observed as a serological marker for inflammation in systemic sclerosis

  • Significant activation of ATF2 in LPS-induced hepatitis and HCl/EtOH-induced gastritis

• Potential suppressive roles:

  • ATF2-mutant mice showed higher death rates when treated with LPS and D-galactosamine, suggesting protective functions

  • Conflicting findings on ATF2's involvement in hepatic inflammation exist

Using ATF2 (Ab-472) Antibody to study inflammatory processes may involve:

• Western blot analysis of tissue samples from inflammatory models

• Analysis of ATF2 expression patterns across different inflammatory cell populations

• Investigation of ATF2's interaction with other transcription factors in inflammatory signaling

How does ATF2 contribute to amino acid starvation response and autophagy gene regulation?

ATF2 plays a crucial role in amino acid starvation response and autophagy gene regulation:

• Chromatin immunoprecipitation (ChIP) studies revealed that binding of ATF2 and ATF4 to CHOP AARE (amino acid response element) is associated with acetylation of histones H4 and H2B in response to amino acid starvation .

• Time course analysis showed:

  • Phosphorylation of ATF2 on Thr71 precedes histone acetylation, ATF4 binding, and CHOP mRNA increase

  • ATF2 binding to CHOP AARE remains constitutive throughout amino acid starvation, while ATF4 binding increases

• The eIF2α/ATF4 pathway directs an autophagy gene transcriptional program in response to amino acid starvation or endoplasmic reticulum stress, with ATF2 playing a regulatory role .

• Different combinations of CHOP and ATF4 binding to target promoters allow differential transcriptional responses according to stress intensity .

For researchers studying autophagy and nutrient stress, the ATF2 (Ab-472) Antibody can be valuable for:

• Analyzing total ATF2 levels during nutrient stress experiments

• Complementing phospho-specific ATF2 antibodies to distinguish between expression changes and activation changes

• Examining ATF2's interaction with autophagy-related transcriptional networks

What is the relationship between ATF2 and neuropathic pain, and how can ATF2 (Ab-472) Antibody contribute to this research?

Research has identified significant connections between ATF2 and neuropathic pain:

• ATF2 expression patterns in neuropathic pain models:

  • ATF2 is constitutively expressed in approximately 41-43% of DRG neurons in naïve and sham-operated rats

  • Nerve injury enhances ATF2 immunoreactivity in injured L5 and L6 DRGs, but not in uninjured L4 DRG

  • Nerve injury increased ATF2 immunoreactivity in superficial and deep laminae of the spinal cord

• Temporal expression changes following nerve injury:

  Condition	L4	L5	L6	Spinal Cord (Mean Fluorescence Intensity)
  Naïve	42.9%	43.5%	42.8%	525 ± 53.2
  Sham	41.3%	42.4%	41.1%	508.4 ± 81.7
  3 days post-injury	46.6%	34.6%*	35.3%*	856 ± 94.7**
  7 days post-injury	42.2%	55.6%*	59.1%**	1100 ± 106.2***
  14 days post-injury	42.1%	66.6%**	69.3%**	1471 ± 179.2***
  21 days post-injury	42.9%	72.3%***	76.5%***	1872 ± 112.8***

  *P < 0.05, **P < 0.01, and ***P < 0.001 versus naïve group

• Functional role in pain maintenance:

  • Intrathecal injection of ATF2 siRNA or anti-ATF2 antibody transiently reversed nerve injury-induced tactile allodynia and thermal hyperalgesia

  • ATF2 appears to have a pronociceptive role in pathological conditions (nerve injury) while potentially having a tonic antinociceptive role in normal conditions

Using ATF2 (Ab-472) Antibody in neuropathic pain research allows:

What are the optimal conditions for ATF2 (Ab-472) Antibody in chromatin immunoprecipitation (ChIP) experiments?

For effective ChIP experiments using ATF2 (Ab-472) Antibody:

• Cell preparation and cross-linking:

  • Transfer cells to appropriate media 12 hours before experiments

  • Cross-link protein-DNA complexes by adding formaldehyde directly to culture medium (final concentration 1%)

  • Stop reaction after 8 minutes with glycerol (final concentration 0.125 M)

• Chromatin shearing:

  • Sonicate cross-linked chromatin using a Vibra cell sonicator

  • Use 10 bursts of 30 seconds at power 2 with 1-minute cooling on ice between bursts

  • Aim for DNA fragments averaging 400 bp

• Immunoprecipitation:

  • Use extracts from 1 × 10⁷ cells incubated with 5 μg of antibody

  • Include a non-specific antibody control (e.g., rabbit anti-chicken IgG)

  • Precipitate antibody-bound complexes using protein A-Agarose beads

• Expected results:

  • This protocol has successfully demonstrated ATF2 binding to the CHOP AARE (amino acid response element) in response to amino acid starvation

How can I distinguish between ATF2 (Ab-472) detection and phospho-specific ATF2 antibody results in experimental design?

When planning experiments involving ATF2, understanding the distinction between total and phosphorylated ATF2 detection is crucial:

What are the limitations of using ATF2 (Ab-472) Antibody in tissue-specific applications?

Understanding the limitations of ATF2 (Ab-472) Antibody in various tissues is essential for experimental design:

• Tissue-specific expression patterns:

  • ATF2 exhibits differential expression in neuronal subtypes (41-43% of DRG neurons in rat models)

  • In spinal cord, ATF2 is found mainly in superficial laminae (I-III) neurons but not in peptidergic/non-peptidergic neurons

  • Not detected in satellite glial cells, astrocytes, or microglia under normal conditions

• Species-specific considerations:

  • The antibody reacts with human, mouse, and rat samples

  • Validation across other species may be necessary before use

• Subcellular localization changes:

  • Under normal conditions, ATF2 is predominantly nuclear

  • Nerve injury can cause ATF2 translocation from nucleus to cytoplasm

  • This dynamic localization may require specialized cell fractionation protocols for accurate quantification

• Potential cross-reactivity:

  • ATF2 has numerous synonyms and variants (including ATF2_HUMAN, cAMP-dependent transcription factor ATF-2, CREB2, etc.)

  • Sequence similarity with other transcription factors may require additional validation in specific experimental contexts

How can I optimize immunofluorescence studies using ATF2 (Ab-472) Antibody?

For successful immunofluorescence applications with ATF2 (Ab-472) Antibody:

• Sample preparation:

  • For nervous system tissues, tissues should be sectioned appropriately (e.g., DRG, spinal cord sections)

  • For cell culture, appropriate fixation methods should be employed

• Antibody concentration:

  • Recommended dilution for immunohistochemistry: 1:50-1:100

  • Optimal working dilution should be determined by the end user for specific applications

• Co-staining markers for enhanced interpretation:

  • Neuronal markers: NeuN for neuronal bodies

  • Subtype markers: CGRP (peptidergic neurons), IB4 (non-peptidergic neurons)

  • Glial markers: GFAP (astrocytes/satellite glial cells), OX-42 (microglia)

• Image acquisition:

  • Confocal microscopy with 63X/1.32 oil immersion has been successfully used

  • Optical sections at 1024 × 1024 pixels, averaged eight times to reduce noise

  • Analysis using software like ZenZ Blue Edition or ImageJ for quantification

• Quantification approaches:

  • Percentage of ATF2+ neurons: Count number of ATF2+ neurons divided by total NeuN+ neurons × 100

  • Cell size analysis: Divide DRG neurons into small (<600 μm²), medium (600-1200 μm²), and large (>1200 μm²) categories

  • Mean fluorescence intensity measurement for comparing expression levels across conditions

What are common issues encountered when using ATF2 (Ab-472) Antibody and how can they be resolved?

When working with ATF2 (Ab-472) Antibody, researchers may encounter several challenges:

• High background in Western blot applications:

  • Increase blocking time (5% non-fat milk or BSA in TBST)

  • Use more stringent washing procedures (increase time/number of washes)

  • Optimize antibody dilution (try 1:1000-1:3000 range)

  • Ensure proper blocking of non-specific binding sites

• Weak or absent signal:

  • Verify protein expression in your sample (ATF2 expression varies by tissue/cell type)

  • Check protein transfer efficiency

  • Consider longer exposure times

  • Increase antibody concentration (try 1:500 dilution)

  • Ensure proper storage conditions to maintain antibody activity

• Nuclear vs. cytoplasmic localization discrepancies:

  • ATF2 can translocate from nucleus to cytoplasm under certain conditions (e.g., nerve injury)

  • Use proper cellular fractionation techniques for Western blot

  • Include nuclear and cytoplasmic markers in immunofluorescence studies

• Cross-reactivity concerns:

  • Include appropriate negative controls

  • Consider preabsorption with immunizing peptide if available

  • Verify specificity with siRNA knockdown experiments (as demonstrated in neuropathic pain models )

How can I integrate ATF2 (Ab-472) Antibody with other molecular techniques for comprehensive pathway analysis?

For comprehensive analysis of ATF2-mediated pathways:

• Combine with gene expression analysis:

  • Use ATF2 antibody to confirm protein levels while measuring target gene expression

  • For amino acid starvation response, measure ATF2 binding alongside CHOP mRNA levels

  • Primers for p62 transcriptional activity: forward 5′-GCTTCCAGGCGCACTACC-3′, reverse 5′-GAACCGCTGGATGTTAGATGT-3′ (normalize to β-actin)

• Promoter analysis using luciferase constructs:

  • Clone promoter fragments into pGL3-basic reporter luciferase construct

  • Create wild-type and mutated AARE sequences to test ATF2 binding specificity

  • Example mutation: 5′-TGATGACAC-3′ to 5′-CTAGTACAC-3′

• Chromatin dynamics assessment:

  • Combine ChIP using ATF2 (Ab-472) Antibody with histone modification analysis

  • In amino acid starvation models, ATF2 binding correlates with acetylation of histones H4 and H2B

• Interaction with other transcription factors:

  • Co-immunoprecipitation to study ATF2/c-Jun heterodimer formation

  • Sequential ChIP to identify co-occupancy of promoters

  • In IFN-β studies, examine ATF2 alongside IRF3 levels

How do ATF2 (Ab-472) Antibody results compare with phospho-specific antibodies in specific research contexts?

Understanding the relationship between total and phosphorylated ATF2 provides important insights:

• In amino acid starvation studies:

  • Total ATF2 binding to CHOP AARE remains constitutive

  • Phosphorylation at Thr71 increases within 30 minutes of leucine deprivation

  • This temporal separation helps identify activation versus recruitment events

• In interferon regulation studies:

  • Total ATF2 levels are enriched in IFN-β-producing cells compared to non-producing cells

  • Phosphorylated IRF3 levels remain similar between cell populations

  • This suggests basal ATF2 expression, not just phosphorylation state, influences IFN-β production

• In neuropathic pain models:

  • Nerve injury increases total ATF2 immunoreactivity in L5/L6 DRGs and spinal cord

  • Increased ATF2 is observed in cell nucleus at 7 days and in both nucleus and cytoplasm at 14-21 days

  • This suggests that both expression levels and subcellular localization are relevant to pain mechanisms

• Comparative analysis recommendations:

  • Always include both total and phospho-specific antibodies when studying ATF2 activation

  • Calculate phospho/total ratio to normalize for expression differences

  • Consider subcellular localization changes alongside phosphorylation changes