MRT4 Antibody

What is MRT4 protein and what cellular functions does it perform?

MRT4 (mRNA turnover 4 homolog) is a 236-amino-acid-long nuclear protein that plays a critical role in mRNA turnover and ribosome assembly. The protein possesses a putative bipartite nuclear localization signal (NLS) at the N-terminal region followed by two well-conserved domains: an rRNA-binding domain and a translation factor (TF) binding domain . In eukaryotic cells, MRT4 functions as a key component in ribosome biogenesis and mRNA decay pathways.

Structurally, the protein has a calculated molecular weight of approximately 28 kDa, though the observed molecular weight in experimental conditions typically ranges between 28-30 kDa . Recent studies using temperature-sensitive yeast strains have demonstrated that defects in MRT4 lead to decay for multiple mRNAs, highlighting its importance in RNA metabolism .

What are the common applications for MRT4 antibody in research?

MRT4 antibody serves several important functions in molecular biology research:

• Western Blotting (WB): The primary application, with recommended dilutions ranging from 1:500 to 1:2400 depending on sample type .

• ELISA: For quantitative detection of MRT4 protein levels in various samples .

• Immunohistochemistry: For localization studies in tissue sections.

• Immunoprecipitation: For protein-protein interaction studies involving MRT4.

The antibody has demonstrated reactivity with human, mouse, and rat samples, making it versatile for comparative studies across these species . Researchers should note that optimal dilutions may vary depending on the specific experimental system and should be determined empirically.

What sample types can be successfully analyzed using MRT4 antibody?

Research has validated MRT4 antibody effectiveness across multiple sample types:

Experimental validation has demonstrated positive Western Blot detection in human skeletal muscle tissue, mouse heart tissue, mouse brain tissue, and HEK-293 cells . This diversity of sample types makes MRT4 antibody suitable for both in vitro cellular studies and in vivo tissue analyses, providing researchers flexibility in experimental design based on their specific research questions.

How should MRT4 antibody be stored for optimal stability?

For maximum stability and activity retention, MRT4 antibody should be stored at -20°C in its provided buffer consisting of PBS with 0.02% sodium azide and 50% glycerol at pH 7.3 . Under these storage conditions, the antibody remains stable for one year after shipment. Importantly, aliquoting is unnecessary for -20°C storage, which simplifies laboratory handling protocols .

For smaller volume products (20μl sizes), the presence of 0.1% BSA in the formulation provides additional stability . Researchers should avoid repeated freeze-thaw cycles as these can compromise antibody performance through protein denaturation and aggregation.

What are the optimization strategies for MRT4 antibody in Western blotting?

Optimization of MRT4 antibody for Western blotting requires systematic adjustment of several parameters:

• Dilution Optimization: While the recommended dilution range is 1:500-1:2400, researchers should perform a dilution series experiment to determine optimal signal-to-noise ratio for their specific sample type .

• Blocking Protocol: Optimizing blocking conditions is crucial. Use 5% non-fat milk or BSA in TBST, with a minimum blocking time of 1 hour at room temperature.

• Incubation Parameters: For primary antibody (MRT4), overnight incubation at 4°C typically yields better results than shorter incubations at room temperature.

• Sample Loading: Based on experimental data, optimal protein loading ranges from 10-30μg total protein per lane, depending on MRT4 expression levels in your sample.

• Detection System Selection: ECL-based chemiluminescence detection systems have demonstrated superior sensitivity for MRT4 detection compared to colorimetric methods.

It's important to note that optimization is sample-dependent, and researchers are advised to check validation data galleries for reference results with similar sample types .

How can researchers troubleshoot non-specific binding or weak signals when using MRT4 antibody?

When encountering non-specific binding or weak signals with MRT4 antibody, consider these methodological approaches:

For Non-specific Binding:

• Increase Antibody Dilution: Test higher dilutions (e.g., 1:2000-1:2400) to reduce background .

• Modify Blocking Conditions: Extend blocking time to 2 hours or switch blocking agent (milk vs. BSA).

• Increase Wash Stringency: Add an additional wash step or increase wash buffer detergent concentration.

• Use Additives: Add 0.1% Tween-20 to antibody dilution buffer to reduce non-specific interactions.

For Weak Signals:

• Decrease Antibody Dilution: Test lower dilutions (e.g., 1:500) to enhance signal strength .

• Increase Protein Loading: Load up to 50μg total protein per lane.

• Extend Exposure Time: For chemiluminescence detection, increase exposure time incrementally.

• Enhance Signal Amplification: Consider using signal enhancement systems compatible with your detection method.

• Optimize Transfer Conditions: For proteins in the 28-30 kDa range like MRT4, semi-dry transfer at 15V for 30 minutes has shown optimal results .

Maintaining proper control experiments, including positive controls (HEK-293 cells express detectable levels of MRT4) and negative controls (secondary antibody only), is essential for accurate troubleshooting .

What expression systems and purification strategies are most effective for recombinant MRT4 protein production?

Based on systematic experimental studies, these methodological approaches have proven effective for recombinant MRT4 production:

Expression Systems:

• E. coli BL21(DE3): This bacterial expression system has demonstrated high-yield soluble expression of MRT4 when combined with pET23a(+) vector systems .

• Induction Parameters: Optimal expression occurs with 0.5mM IPTG concentration at 25°C, which produces higher soluble protein yield compared to 20°C induction .

Purification Strategy:

• Immobilized Metal Affinity Chromatography (IMAC): Ni-NTA resin columns effectively purify His-tagged MRT4 protein to homogeneity .

• Purification Yield: This method produces approximately 3mg/L of homogeneously purified recombinant MRT4 protein .

• Validation: Successful purification can be confirmed via SDS-PAGE analysis showing a single band at the expected molecular mass (~29 kDa for His-tagged MRT4) and Western blotting with anti-His antibody .

The purified protein maintains structural integrity and functional activity, making it suitable for subsequent biochemical and biophysical characterization, crystallization studies, and identification of new interacting partners .

How does MRT4 gene expression correlate with specific human diseases?

Research has identified significant associations between MRT4 gene expression and specific human genetic disorders:

• Robinow Syndrome, Autosomal Dominant 1 (RSAD1): This disorder is characterized by acral dysostosis with genital and facial abnormalities. MRT4 gene expression alterations have been implicated in its pathophysiology .

• Shwachman-Diamond Syndrome 1 (SDS1): This condition manifests as bone marrow dysfunction and pancreatic insufficiency. MRT4 dysfunction has been associated with molecular pathways involved in SDS1 development .

Methodologically, researchers investigating these disease associations should:

• Employ qRT-PCR to quantify MRT4 expression levels in patient samples

• Conduct immunohistochemistry to evaluate protein localization in affected tissues

• Perform functional studies using patient-derived cells to assess impact on ribosome assembly and mRNA turnover

• Consider sequencing analysis for potential mutations in MRT4 coding or regulatory regions

These approaches provide complementary data points that can establish mechanistic links between MRT4 expression patterns and disease phenotypes.

What controls should be included when validating MRT4 antibody specificity?

A comprehensive validation strategy for MRT4 antibody requires multiple control experiments:

• Positive Controls: Include samples known to express MRT4, such as:

  • Human skeletal muscle tissue

  • Mouse heart and brain tissue

  • HEK-293 cells

• Negative Controls:

  • Secondary antibody-only controls to detect non-specific binding

  • Samples from MRT4 knockout models (if available)

  • Pre-incubation of antibody with immunizing peptide (blocking peptide controls)

• Orthogonal Validation:

  • Correlation with mRNA expression data

  • Confirmation with alternative MRT4 antibodies targeting different epitopes

  • Correlation with tagged-MRT4 expression in recombinant systems

• Protocol Controls:

  • Loading controls (β-actin, GAPDH) for normalization

  • Molecular weight markers to confirm expected band size (28-30 kDa)

Documentation of these controls significantly enhances result validity and reproducibility, especially when publishing or presenting antibody-based experimental findings.

How can researchers differentiate between MRT4 and structurally similar proteins?

Differentiating MRT4 from structurally similar proteins, particularly those in the ribosomal assembly pathway, requires specific methodological approaches:

• Sequence Analysis: Perform multiple sequence alignment using tools like ClustalW to identify unique regions in MRT4 compared to similar proteins. This is particularly important since MRT4 proteins from Chaetomium, Saccharomyces, and humans share conserved domains including the rRNA-binding domain and translation factor (TF) binding domain .

• Epitope Mapping: Select antibodies targeting unique epitopes not found in similar proteins. The N-terminal region containing the bipartite nuclear localization signal (NLS) offers higher sequence variability than the conserved functional domains .

• Molecular Weight Discrimination: Use high-resolution SDS-PAGE to separate proteins based on subtle molecular weight differences. MRT4 exhibits an observed molecular weight of 28-30 kDa, which may differ from related proteins .

• Subcellular Localization: Employ immunofluorescence to distinguish proteins based on their cellular distribution. MRT4's nuclear localization, driven by its NLS sequence, can help differentiate it from cytoplasmic homologs .

• Functional Assays: Design experiments that specifically assess MRT4's role in mRNA turnover versus other functions of similar proteins.

These approaches, used in combination, provide robust discrimination between MRT4 and structurally similar proteins in experimental systems.

What are the methodological considerations for studying MRT4's role in ribosome assembly?

Investigating MRT4's function in ribosome assembly requires specialized experimental approaches:

• Ribosome Profiling:

  • Generate polysome profiles using sucrose gradient centrifugation

  • Monitor changes in 60S subunit assembly upon MRT4 depletion or mutation

  • Analyze ribosome biogenesis intermediates using northern blotting with pre-rRNA-specific probes

• Protein-RNA Interactions:

  • Employ RNA immunoprecipitation (RIP) using MRT4 antibody to identify rRNA binding partners

  • Perform cross-linking and immunoprecipitation (CLIP) to map precise MRT4 binding sites on rRNA

  • Use electrophoretic mobility shift assays (EMSA) to quantify binding affinity to specific rRNA segments

• Protein-Protein Interactions:

  • Conduct co-immunoprecipitation with MRT4 antibody to identify protein partners in the ribosome assembly pathway

  • Validate interactions using proximity ligation assays or fluorescence resonance energy transfer (FRET)

  • Map interaction domains through truncation mutants and domain-specific antibodies

• Functional Depletion Studies:

  • Implement siRNA or CRISPR/Cas9-mediated MRT4 depletion

  • Analyze consequences on pre-rRNA processing and 60S subunit maturation

  • Monitor nuclear export of pre-60S particles using fluorescent reporters

These methodologies provide complementary approaches to understand MRT4's mechanistic role in the complex process of ribosome assembly, generating both qualitative and quantitative data about its function.

How should researchers interpret variations in MRT4 antibody reactivity across different species?

When interpreting cross-species reactivity patterns with MRT4 antibody, consider these methodological guidelines:

• Sequence Homology Analysis:

  • Perform sequence alignment of MRT4 between human, mouse, and rat to identify conserved epitopes

  • Calculate percent identity in the antibody's epitope region to predict cross-reactivity likelihood

  • The high conservation of rRNA-binding domains and translation factor binding domains across species explains the observed cross-reactivity

• Validation Hierarchy:

  • Consider human samples as primary validation (most directly relevant to the immunogen)

  • Mouse and rat samples represent secondary validation (confirmed cross-reactivity)

  • For untested species, preliminary experiments with positive controls are essential

• Signal Interpretation:

  • Similar molecular weights across species (28-30 kDa) suggest conservation of protein structure

  • Minor variations in band intensity may reflect species-specific post-translational modifications

  • Adjust loading amounts to compensate for expression level differences between species

• Application-Specific Considerations:

  • Western blot cross-reactivity does not automatically predict immunohistochemistry performance

  • For each new species or application, titration of antibody concentration is recommended

This multi-faceted approach to interpreting cross-species reactivity enhances experimental design robustness and facilitates accurate comparative studies across model organisms.

What are the implications of MRT4 research for understanding genetic diseases?

MRT4 research has significant implications for understanding the molecular basis of specific genetic disorders:

• Robinow Syndrome, Autosomal Dominant 1 (RSAD1):

  • Methodological approach: Sequence MRT4 gene in RSAD1 patients to identify potential mutations

  • Analyze facial and skeletal development pathways potentially disrupted by MRT4 dysfunction

  • Create cellular models expressing mutant MRT4 to characterize molecular consequences

  • The connection between ribosome biogenesis defects and developmental abnormalities in RSAD1 represents a crucial research direction

• Shwachman-Diamond Syndrome 1 (SDS1):

  • Methodological approach: Evaluate MRT4 expression in bone marrow and pancreatic tissues from SDS1 patients

  • Investigate connections between mRNA turnover dysfunction and hematopoietic abnormalities

  • Develop therapeutic approaches targeting the MRT4 pathway in SDS1 cellular models

  • The bone marrow dysfunction and pancreatic insufficiency characteristics of SDS1 may reflect tissue-specific consequences of ribosome assembly defects

• Research Translation:

  • Patient-derived induced pluripotent stem cells (iPSCs) can be valuable for studying MRT4's role in disease-relevant cell types

  • Mouse models with MRT4 mutations may recapitulate aspects of human genetic disorders

  • Therapeutic strategies could target either MRT4 directly or compensatory pathways that bypass MRT4 dysfunction

These research implications highlight the importance of MRT4 beyond basic cellular processes, connecting fundamental molecular mechanisms to clinically relevant human disorders.

How can MRT4 antibody be integrated into broader research workflows studying ribosome biology?

Integration of MRT4 antibody into comprehensive ribosome biology research requires strategic experimental design:

This integrated approach positions MRT4 antibody as a valuable tool within broader research frameworks investigating fundamental ribosome biology and its dysregulation in disease states.

What biophysical techniques are most appropriate for characterizing MRT4 protein structure and interactions?

Comprehensive structural and interaction characterization of MRT4 requires multiple complementary biophysical approaches:

• Structural Analysis Techniques:

  • X-ray Crystallography: Requires homogeneously purified recombinant MRT4

  • Nuclear Magnetic Resonance (NMR): For mapping dynamic regions and resolving solution structure

  • Cryo-Electron Microscopy: Particularly valuable for visualizing MRT4 within ribosomal complexes

  • Circular Dichroism (CD) Spectroscopy: To assess secondary structure composition and stability

• Interaction Analysis Methodologies:

  • Surface Plasmon Resonance (SPR): For quantifying binding kinetics with RNA and protein partners

  • Isothermal Titration Calorimetry (ITC): To determine thermodynamic parameters of binding events

  • Microscale Thermophoresis (MST): For measuring interactions in near-native conditions

  • Fluorescence Spectroscopy: As suggested by research, fluorescence techniques can characterize MRT4's structural properties and binding interactions

• Computational Approaches:

  • Molecular Dynamics Simulations: To model dynamic behavior of MRT4 domains

  • PIPSA Analysis: This electrostatic interaction property analysis has successfully classified Mrt4-like proteins across species

  • Structural Homology Modeling: Given the conservation between MRT4 and P0 protein, comparative modeling provides structural insights

These methodological approaches generate complementary datasets that, when integrated, provide comprehensive understanding of MRT4's structural features and molecular interactions critical to its function in ribosome assembly.

What are the specific considerations for using MRT4 antibody in immunoprecipitation experiments?

Successful immunoprecipitation (IP) experiments with MRT4 antibody require optimization of several critical parameters:

• Lysis Buffer Optimization:

  • Use buffers containing 150mM NaCl, 50mM Tris-HCl (pH 7.5), 0.5% NP-40, and protease inhibitors

  • For nuclear proteins like MRT4, include DNase I treatment to reduce chromatin-mediated precipitation

  • Consider lower detergent concentrations (0.3-0.5%) to preserve weaker interactions

• Antibody Binding Conditions:

  • Pre-clear lysates thoroughly to reduce non-specific binding

  • Optimize antibody-to-lysate ratio (typically starting with 2-5μg antibody per mg total protein)

  • Extend incubation time to overnight at 4°C to maximize specific binding

  • For MRT4's nuclear protein complex isolation, gentle rotation rather than vigorous mixing preserves interactions

• Precipitation Strategy:

  • Use protein A/G beads for rabbit polyclonal MRT4 antibodies

  • Pre-block beads with BSA to minimize non-specific protein binding

  • Implement stringent washing steps (at least 4-5 washes) while preserving specific interactions

• Complex Analysis:

  • Elute under native conditions for functional studies of MRT4 complexes

  • For interactome analysis, consider on-bead digestion followed by mass spectrometry

  • Validate novel interactions with reciprocal IP using antibodies against putative partners

• Controls:

  • Include IgG control from the same species as the MRT4 antibody

  • Perform IP in cells with MRT4 knockdown as a specificity control

  • Include input samples (pre-IP) for quantitative analysis of enrichment

These methodological considerations enhance the specificity and yield of MRT4 immunoprecipitation experiments, facilitating the characterization of its protein-protein and protein-RNA interactions in various cellular contexts.

How can MRT4 antibody contribute to understanding non-canonical functions of the protein?

Investigating non-canonical functions of MRT4 beyond ribosome assembly requires strategic application of MRT4 antibody in diverse experimental contexts:

• Stress Response Pathway Analysis:

  • Use MRT4 antibody in stress granule co-localization studies

  • Implement proximity labeling techniques with MRT4 antibody to identify stress-specific interaction partners

  • Monitor MRT4 phosphorylation status under various cellular stresses using phospho-specific antibodies

• Transcriptome-wide Analysis:

  • Combine RNA immunoprecipitation with MRT4 antibody and RNA sequencing (RIP-seq)

  • Identify non-ribosomal RNA targets that may reveal novel regulatory functions

  • Correlate MRT4 binding with mRNA stability measurements in various cellular conditions

• Cellular Compartment Exploration:

  • Use subcellular fractionation followed by MRT4 immunoblotting to detect non-nuclear pools

  • Perform high-resolution imaging with MRT4 antibody to identify novel subcellular localizations

  • Investigate potential shuttling between compartments using live-cell imaging approaches

• Disease-specific Functions:

  • Examine MRT4 expression and localization in genetic disease models

  • Correlate patterns with specific phenotypes in Robinow Syndrome and Shwachman-Diamond Syndrome

  • Explore potential tissue-specific functions through immunohistochemistry in diverse tissues

These methodological approaches can reveal unexpected MRT4 functions that extend beyond its established role in ribosome biogenesis, potentially identifying novel therapeutic targets for associated genetic disorders.

What are the methodological approaches for investigating MRT4's role in cancer biology?

Elucidating MRT4's potential role in cancer biology requires systematic experimental strategies:

• Expression Analysis in Cancer:

  • Quantify MRT4 expression across cancer types using antibody-based techniques

  • Correlate expression levels with clinical parameters and patient outcomes

  • Perform immunohistochemistry on tissue microarrays to assess MRT4 as a potential biomarker

• Functional Studies in Cancer Models:

  • Implement CRISPR/Cas9-mediated MRT4 knockdown or overexpression in cancer cell lines

  • Assess consequences on proliferation, migration, and response to chemotherapeutics

  • Use MRT4 antibody to monitor protein levels and localization in these modified systems

• Mechanistic Investigations:

  • Explore connections between altered ribosome biogenesis and cancer hallmarks

  • Investigate potential roles in stress adaptation through translational reprogramming

  • Examine interactions with known oncogenes or tumor suppressors via co-immunoprecipitation

• Therapeutic Implications:

  • Screen for small molecules that modulate MRT4 expression or function

  • Evaluate combination approaches targeting both MRT4 and established cancer pathways

  • Develop MRT4-based strategies for cancer subtypes with ribosome biogenesis dependencies

These methodological approaches provide a framework for investigating whether alterations in MRT4 expression or function contribute to cancer development, progression, or therapeutic response, potentially identifying novel intervention strategies.

What are the current limitations in MRT4 antibody research and how might they be addressed?

Current limitations in MRT4 antibody research present opportunities for methodological advancement:

• Epitope Coverage Limitations:

  • Current antibodies may target limited epitopes within MRT4

  • Solution: Develop antibody panels targeting different MRT4 domains (N-terminal NLS, rRNA-binding, and TF binding domains)

  • Implement epitope mapping to precisely characterize binding sites of existing antibodies

• Species Reactivity Constraints:

  • While human, mouse, and rat reactivity is established , other model organisms lack validation

  • Solution: Systematically validate cross-reactivity in zebrafish, Drosophila, and other research models

  • Develop species-specific antibodies where conservation is insufficient for cross-reactivity

• Application Limitations:

  • Optimization for certain techniques (super-resolution microscopy, ChIP-seq) remains underdeveloped

  • Solution: Specifically validate and optimize MRT4 antibodies for emerging technologies

  • Consider developing application-specific modifications (conjugation to fluorophores, enzymes)

• Quantification Challenges:

  • Absolute quantification of MRT4 levels remains difficult

  • Solution: Develop quantitative assays using recombinant MRT4 standards

  • Implement multiplexed approaches that simultaneously measure MRT4 and relevant interacting partners

Addressing these limitations through methodological innovation will expand the utility of MRT4 antibodies across broader research applications and model systems.

What emerging technologies might enhance MRT4 research in the next decade?

Several emerging technologies hold promise for advancing MRT4 research:

• Advanced Microscopy Applications:

  • Super-resolution microscopy to visualize MRT4 within sub-nuclear structures

  • Lattice light-sheet microscopy for real-time tracking of MRT4 during ribosome assembly

  • Correlative light and electron microscopy (CLEM) to place MRT4 in ultrastructural context

  • These approaches will provide unprecedented spatial resolution for understanding MRT4 function

• Proteomics Innovations:

  • Proximity labeling methods (BioID, APEX) to map the dynamic MRT4 interactome

  • Hydrogen-deuterium exchange mass spectrometry to probe structural changes upon binding

  • Cross-linking mass spectrometry to capture transient interactions in ribosome assembly

  • These methods will reveal MRT4's interaction network with temporal and spatial resolution

• Genomic Engineering Approaches:

  • CRISPR-based endogenous tagging for live-cell visualization of MRT4

  • Base editing to introduce subtle mutations mimicking disease variants

  • CRISPRi/a for temporal control of MRT4 expression

  • These techniques will enable precise manipulation of MRT4 in physiologically relevant contexts

• Computational and AI Integration:

  • AlphaFold2 and RoseTTAFold for improved structural predictions

  • Machine learning analysis of MRT4-dependent gene expression patterns

  • Network analyses integrating MRT4 into broader cellular pathways

  • These computational approaches will accelerate hypothesis generation and testing