amer2 Antibody

What is AMER2 protein and what specific functions does it perform in cellular pathways?

AMER2 (also known as FAM123A or APC Membrane Recruitment Protein 2) is a membrane-associated protein with significant roles in both microtubule dynamics and Wnt signaling regulation. The protein consists of 671 amino acids (human canonical form) with a molecular weight of approximately 66-69.5 kDa .

The protein performs several key functions:

• Recruits APC (Adenomatous Polyposis Coli) to the plasma membrane by binding to phosphatidylinositol 4,5-bisphosphate lipids via lysine-rich motifs (K1 and K2)

• Acts as a negative regulator of the canonical Wnt signaling pathway involved in neuroectodermal patterning

• Interacts with EB1 (End-binding Protein 1) via specific (S/T)xIP motifs and recruits it to the plasma membrane

• Stabilizes microtubules when co-expressed with EB1

• Plays a role in directed cell migration and convergent extension movements during development

Research indicates that AMER2 exists in two splice variants: Amer2-S1 (full-length) and Amer2-S2 (lacking part of APC-binding domain A1 but retaining domain A2) .

How do I determine the appropriate AMER2 antibody for my specific research application?

Selection of an appropriate AMER2 antibody should be based on:

Application compatibility:

• For Western Blot: Multiple validated options exist, including ABIN2786237 (N-terminal specific) and PA558794

• For immunofluorescence: Consider antibodies validated for this application

• For multiple applications: Select antibodies validated across your required techniques

Target species reactivity:

Epitope considerations:

• N-terminal targeting antibodies (like ABIN2786237) are useful for detecting full-length AMER2

• For studying specific interactions (e.g., APC binding), choose antibodies that target regions away from interaction domains

• For splice variant distinction, select antibodies targeting unique regions

Validation status:

• Review published literature where antibodies have been used successfully

• Check manufacturer validation data (Western blot bands at expected MW)

What are the optimal conditions for using AMER2 antibodies in Western blotting experiments?

Based on validated protocols from research studies and manufacturer recommendations:

Sample preparation:

• Cell/tissue lysis: Use buffer containing 0.5% Triton X-100 for efficient extraction

• Protein amount: Load 30μg of whole cell extracts per lane

• Gel concentration: 10% SDS-PAGE is appropriate for resolving AMER2 (66-69.5 kDa)

Antibody conditions:

• Primary antibody dilutions:

  • ABIN2786237: Optimal working dilutions should be determined experimentally

  • ab229165: 1/500 dilution is effective

  • PA558794: Start with manufacturer's recommended dilution (typically 1:1000)

• Incubation: Overnight at 4°C for optimal binding with minimal background

• Secondary antibody: HRP-conjugated anti-rabbit IgG (as most AMER2 antibodies are rabbit-derived)

Detection method:

• ECL (Enhanced Chemiluminescence) technique has been validated for AMER2 detection

• Expected band size: ~66-69.5 kDa for full-length AMER2

Controls:

• Positive control: IMR32 (human brain neuroblast cell line) expresses detectable levels of AMER2

• Negative control: Consider knockdown/knockout samples or non-expressing cell lines

How can AMER2 antibodies be effectively used to study protein-protein interactions in experimental systems?

Research on AMER2 interactions with APC, EB1, and β-catenin provides methodological insights:

Co-immunoprecipitation approaches:

• Transfect cells with tagged AMER2 constructs (FLAG-tag recommended)

• Lyse cells in buffer containing 0.5% Triton X-100

• Immunoprecipitate using anti-AMER2 antibody or anti-tag antibody

• Blot for interaction partners (APC, EB1, β-catenin, axin, conductin)

Mutation analysis protocols:

• Create point mutations in key domains (e.g., SKNN/TKNN mutations in EB1-binding motifs)

• Compare immunoprecipitation efficiency with wild-type AMER2

• Analyze downstream effects on microtubule stability using acetylated tubulin as a marker

Membrane recruitment assay:

• Express AMER2 constructs in cells

• Use immunofluorescence to visualize membrane localization

• Co-stain for potential interaction partners

• Analyze colocalization at the plasma membrane

Experimental findings from literature:

• AMER2 co-immunoprecipitates with β-catenin, axin, and conductin when APC fragment (APC1641) is coexpressed

• The amount of EB1 co-immunoprecipitated with AMER2 increases greatly when APC is coexpressed

• AMER2-SKNN/TKNN mutant deficient for EB1 binding fails to stabilize microtubules

How are AMER2 antibodies being used to investigate the protein's role in microtubule dynamics and cell migration?

Research using AMER2 antibodies has revealed sophisticated methods for studying microtubule regulation:

Microtubule stability assessment:

• Co-express AMER2 and EB1 in cellular models (MCF-7 cells recommended)

• Use anti-acetylated tubulin antibody as a marker for stable microtubules

• Perform immunofluorescence to visualize enrichment of stabilized microtubules at the cell cortex

• Compare wild-type AMER2 with EB1-binding deficient mutants (SKNN/TKNN)

Nocodazole resistance assay:

• Transfect U2OS cells with AMER2 and EB1 constructs

• Treat with low doses of nocodazole (2 μg/ml for 1h) to disrupt microtubules

• Stain with anti-α-tubulin antibodies

• Analyze focal retention of microtubules at areas of EB1 membrane localization

Cell migration experimental design:

• Perform knockdown of AMER2 using siRNA in U2OS cells

• Create wounds of defined size (~850 μm) in confluent cell monolayers

• Allow cells to migrate for 12h

• Process for α-tubulin immunofluorescence staining

• Measure wound closure percentage at multiple positions

In vivo convergent extension analysis:

• Use morpholino oligonucleotides for Xenopus Amer2 knockdown

• Analyze XPAPC-expressing paraxial mesoderm

• Measure length/width of negatively stained notochord

Key findings demonstrated that AMER2 knockdown significantly reduced cell migration in wounding assays and disrupted convergent extension movements in Xenopus embryos, establishing its importance in directed cell movement .

What methodological approaches can determine the specific interactions between AMER2 and components of the Wnt signaling pathway?

Research employing AMER2 antibodies has elucidated several sophisticated approaches:

Membrane recruitment analysis:

• Express Amer2 constructs with APC fragments containing binding domains for β-catenin and destruction complex components

• Perform co-immunoprecipitation to detect protein complexes

• Analyze localization using membrane fractionation techniques

• Verify interaction with phosphatidylinositol 4,5-bisphosphate lipids via lysine-rich motifs (K1 and K2)

Functional Wnt pathway analysis:

• Transfect cells with Amer2 constructs alongside Wnt reporter constructs (TCF/LEF reporters)

• Measure reporter activity to quantify Wnt pathway suppression

• Compare wild-type Amer2 with membrane-binding deficient mutants

• Assess β-catenin levels after Amer2 knockdown by Western blotting

In vivo developmental studies:

• Perform targeted Amer2 knockdown in Xenopus embryos using morpholino oligonucleotides

• Analyze neuroectodermal patterning

• Conduct rescue experiments using dominant-negative Lef1 mutant that interferes with β-catenin-dependent transcription

• Use whole-mount in situ hybridization to visualize expression patterns

Combined approaches:

• Employ RT-PCR to analyze expression of Amer2 and Wnt pathway components

• Use yeast two-hybrid screening to identify novel interaction partners

• Perform structure-function analysis with deletion constructs to map interaction domains

These methodologies have established Amer2 as a negative regulator of Wnt signaling that functions by recruiting key components of the β-catenin destruction complex to the plasma membrane .

What are common challenges when using AMER2 antibodies and how can they be addressed?

Researchers may encounter several challenges when working with AMER2 antibodies:

Background signal issues:

• Problem: High background in Western blots or immunofluorescence

• Solutions:

  • Increase blocking time/concentration (try 5% BSA or milk in TBST)

  • Optimize antibody dilution (perform titration experiments)

  • Include additional washing steps with higher salt concentration

  • For immunofluorescence, pre-adsorb antibody with acetone powder from non-expressing tissue

Detection sensitivity limitations:

• Problem: Weak signal for endogenous AMER2

• Solutions:

  • Increase protein loading (up to 50μg per lane)

  • Use enhanced detection systems (Super Signal West Femto)

  • Concentrate protein via immunoprecipitation before Western blotting

  • Consider using cell lines with known AMER2 expression (e.g., IMR32)

Splice variant discrimination:

• Problem: Inability to distinguish between Amer2-S1 and Amer2-S2 splice variants

• Solutions:

  • Use antibodies targeting regions specific to each variant

  • Perform RT-PCR to confirm variant expression at mRNA level

  • Run higher percentage gels (12-15%) to better resolve size differences

Antibody storage and stability:

• Problem: Loss of antibody activity over time

• Solutions:

  • For short-term storage, keep at 2-8°C (up to 1 week)

  • For long-term storage, store at -20°C in small aliquots to prevent freeze-thaw cycles

  • Add glycerol (40%) to prevent freeze-thaw damage

  • Check for precipitates before use and centrifuge if necessary

How can researchers validate the specificity of AMER2 antibodies for their experimental system?

Rigorous validation is essential for ensuring experimental reproducibility and accuracy:

Knockdown/knockout controls:

• Perform siRNA-mediated knockdown of AMER2

• Compare antibody reactivity between control and knockdown samples

• Expected outcome: Significant reduction in signal intensity in knockdown samples

Overexpression validation:

• Transfect cells with tagged AMER2 constructs

• Perform parallel detection with anti-tag and anti-AMER2 antibodies

• Expected outcome: Co-localization of signals and increased intensity in transfected cells

Peptide competition assay:

• Pre-incubate antibody with immunizing peptide (if available)

• Use in parallel with untreated antibody

• Expected outcome: Specific signals should be blocked by peptide pre-incubation

Cross-reactivity assessment:

• Test antibody reactivity in multiple species using predicted cross-reactivity information:

  • ABIN2786237: Human (100%), Mouse (100%), Rabbit (86%), Rat (93%)

  • PA558794: Mouse (75% sequence identity), Rat (74% sequence identity)

Western blot validation criteria:

• Observe band at expected molecular weight (~66-69.5 kDa)

• Check for absence of unexpected bands

• Verify reproducibility across multiple experiments and protein preparations

How are AMER2 antibodies contributing to our understanding of neurodevelopmental processes?

AMER2 antibodies have revealed important insights into neural development:

Neuroectodermal patterning:

• Research demonstrates AMER2 expression predominantly in dorsal neuroectoderm and neural tissues in Xenopus embryos

• Knockdown experiments using morpholino oligonucleotides show altered neuroectodermal patterning

• Rescue experiments with dominant-negative Lef1 confirm Wnt pathway involvement

Nervous system expression profile:

• AMER2 shows notable expression in multiple brain regions including hippocampus, cerebral cortex, cerebellum, and caudate

• This expression pattern suggests potential roles in region-specific neural functions

Microtubule dynamics in neural cells:

• AMER2's interaction with EB1 and role in microtubule stabilization may be particularly significant in neurons where microtubule dynamics are crucial for axon growth and synapse formation

• The protein's involvement in cell migration could influence neuronal migration during development

Potential implications for neurodevelopmental disorders:

• Given AMER2's dual roles in Wnt signaling and microtubule dynamics, both of which are critical for brain development, further research with AMER2 antibodies may reveal connections to neurodevelopmental disorders

• Immunohistochemical studies using validated AMER2 antibodies could map expression changes in developmental disorder models

What specialized techniques are emerging for studying AMER2's role in microtubule regulation in different cellular contexts?

Advanced methodological approaches are being developed:

Super-resolution microscopy techniques:

• Apply STORM or PALM imaging with AMER2 antibodies to visualize nanoscale distribution at the plasma membrane

• Use dual-color super-resolution to examine colocalization with EB1 and APC at high precision

• Implement live-cell super-resolution to track dynamic interactions during microtubule stabilization

FRAP (Fluorescence Recovery After Photobleaching) analysis:

• Tag AMER2 with fluorescent proteins and perform FRAP to analyze dynamics at the membrane

• Compare recovery kinetics between wild-type and mutant AMER2 proteins

• Analyze how AMER2 mobility is affected by microtubule stabilization or disruption

Proximity ligation assays:

• Use in situ PLA to visualize and quantify endogenous AMER2-EB1 interactions

• Apply to different cell types to compare interaction patterns

• Combine with microtubule stabilizing/destabilizing agents to assess dynamic changes

Microfluidic migration chambers:

• Develop gradient-based migration assays with real-time imaging

• Compare wild-type and AMER2-depleted cells for migration defects

• Correlate microtubule dynamics with directional persistence during migration

Organoid models:

• Apply AMER2 antibodies to brain organoid systems to study protein localization in 3D tissue context

• Perform knockdown studies in organoids to assess developmental consequences

• Examine microtubule stability in specific cell populations within organoids

These emerging approaches will provide deeper insights into AMER2's role in coordinating microtubule dynamics and cellular behaviors across different biological contexts.