Recombinant Mouse UPF0694 transmembrane protein C14orf109 homolog

What is the mouse UPF0694 transmembrane protein C14orf109 homolog and how is it related to human TMEM251?

Mouse UPF0694 transmembrane protein C14orf109 homolog (UniProt ID: Q8BH26) is the murine counterpart of human TMEM251 (Transmembrane protein 251, UniProt ID: Q8N6I4). The protein consists of 163 amino acids and functions as a membrane-spanning protein. The mouse gene encoding this protein is often referred to as D230037D09Rik in research literature . Sequence analysis reveals significant conservation between the human and mouse variants, with both sharing key structural motifs characteristic of transmembrane proteins. When designing comparative studies between human and mouse models, researchers should account for these homologous relationships while recognizing species-specific differences in expression patterns and potential functional variations.

How should researchers approach the expression and purification of this recombinant protein?

For optimal expression of recombinant mouse UPF0694 transmembrane protein, E. coli expression systems have been successfully employed, as evidenced by commercially available products . The protein is typically expressed with an N-terminal His-tag to facilitate purification via immobilized metal-ion affinity chromatography (IMAC). After expression, the protein is generally supplied as a lyophilized powder with greater than 90% purity as determined by SDS-PAGE .

The recommended protocols include:

• Expression in E. coli using a vector containing an N-terminal His-tag

• Purification via IMAC under denaturing or non-denaturing conditions depending on research requirements

• Buffer exchange into Tris/PBS-based buffer containing 6% trehalose at pH 8.0

• Lyophilization for long-term storage

• Reconstitution in deionized sterile water to a concentration of 0.1-1.0 mg/mL with 5-50% glycerol for stability

For transmembrane proteins, inclusion of detergents or lipids during purification may be necessary to maintain native conformation and prevent aggregation.

What detection methods are recommended for analyzing expression of mouse UPF0694 transmembrane protein in tissues or cell lines?

Several validated methods exist for detecting the mouse UPF0694 transmembrane protein (D230037D09Rik) in biological samples:

Western Blotting: Polyclonal antibodies targeting D230037D09Rik have been verified for detection in mouse samples, with recommended starting dilutions of 1:200 (dilution range 1:100-1:1000) . The expected molecular weight is approximately 19/15 kDa when analyzed by SDS-PAGE. For optimal results, samples should be prepared using buffers containing mild detergents to solubilize membrane proteins without denaturing critical epitopes.

Immunofluorescence: For subcellular localization studies, immunofluorescence protocols starting at 1:50 dilution (range 1:50-1:500) have been validated . This approach allows visualization of the protein's distribution within cellular compartments when coupled with confocal microscopy.

ELISA: Solid-phase ELISA provides quantitative detection with recommended starting dilutions of 1:30 (range 1:30-1:3000) . This method is particularly useful for high-throughput screening of multiple samples.

For genetic knockdown studies, validated siRNA (sc-142803) and shRNA plasmids (sc-142803-SH) targeting D230037D09Rik are available, along with corresponding lentiviral particles (sc-142803-V) for stable incorporation into difficult-to-transfect cell lines .

How can researchers optimize storage conditions to maintain the stability and activity of the recombinant protein?

Maintaining the stability of recombinant mouse UPF0694 transmembrane protein requires careful attention to storage conditions:

• Long-term storage: Store lyophilized protein at -20°C/-80°C, with -80°C preferred for extended periods

• Working solutions: Store at 4°C for up to one week

• Avoid repeated freeze-thaw cycles: Aliquot reconstituted protein to minimize degradation

• Reconstitution protocol:

  • Briefly centrifuge the vial prior to opening

  • Reconstitute in deionized sterile water to 0.1-1.0 mg/mL

  • Add glycerol to a final concentration of 5-50% (50% recommended)

The addition of glycerol is critical as it prevents freeze-thaw damage by inhibiting ice crystal formation. For experiments requiring native protein conformation, reconstitute in buffers containing mild detergents or lipid micelles to stabilize the transmembrane domains.

What are the recommended approaches for studying protein-protein interactions involving mouse UPF0694 transmembrane protein?

Investigating protein-protein interactions for membrane proteins presents unique challenges. The following methodologies have been optimized for transmembrane proteins like mouse UPF0694:

• Co-immunoprecipitation (Co-IP): Using validated antibodies such as goat polyclonal antibodies against D230037D09Rik . Detergent selection is critical—mild non-ionic detergents (e.g., digitonin, CHAPS, or DDM) are preferred to maintain native interactions.

• Proximity labeling techniques: BioID or APEX2 fusion constructs can identify proximal interacting partners in living cells, particularly valuable for membrane proteins where traditional yeast two-hybrid systems may fail.

• Crosslinking mass spectrometry: Chemical crosslinkers followed by mass spectrometry analysis can capture transient or weak interactions that might be disrupted during conventional Co-IP procedures.

• Split reporter assays: Bimolecular fluorescence complementation (BiFC) or split luciferase assays can visualize interactions in living cells while providing spatial information about where these interactions occur.

When designing these experiments, researchers should consider potential limitations posed by the transmembrane nature of the protein and may need to include appropriate controls to distinguish specific from non-specific membrane protein associations.

What are the optimal cell models for studying mouse UPF0694 transmembrane protein function?

Based on available research and expression patterns, the following cell models are recommended for studying mouse UPF0694 transmembrane protein:

• Mouse cell lines: Given the protein's documented expression in multiple mouse tissues, murine cell lines provide physiologically relevant systems. Validated antibodies have been shown to detect D230037D09Rik in mouse samples .

• Tissue-specific considerations: While comprehensive tissue expression data for this specific protein is limited in the search results, researchers should consider cell types that naturally express this protein for most physiologically relevant outcomes.

• Heterologous expression systems: For controlled overexpression studies, standard mammalian expression systems (HEK293T, CHO) can be utilized with species-specific optimizations.

When selecting cell models, researchers should verify endogenous expression levels of D230037D09Rik through RT-qPCR or Western blotting to establish appropriate baseline measurements before experimental manipulation.

How can researchers effectively design knockout or knockdown experiments to study the function of this protein?

For investigating the function of mouse UPF0694 transmembrane protein through loss-of-function approaches, researchers have multiple validated options:

• RNA interference: Commercially validated siRNA (sc-142803) and shRNA plasmids (sc-142803-SH) targeting D230037D09Rik provide effective knockdown options . For optimal knockdown:

  • Transfect siRNA at 10-50 nM final concentration

  • Assess knockdown efficiency 48-72 hours post-transfection

  • Include scrambled siRNA controls to identify off-target effects

• Stable knockdown: Lentiviral particles (sc-142803-V) enable stable incorporation of shRNA into difficult-to-transfect cell lines . This approach is particularly valuable for long-term studies or when transient transfection efficiency is low.

• CRISPR-Cas9 genome editing: For complete knockout studies, design guide RNAs targeting early exons of D230037D09Rik. Multiple guide RNAs should be tested to identify those with highest editing efficiency and specificity.

• Validation strategy: Regardless of the chosen approach, validation of knockdown/knockout should include:

  • mRNA level assessment (RT-qPCR)

  • Protein level confirmation (Western blot)

  • Phenotypic rescue experiments to confirm specificity

When designing these experiments, researchers should consider potential compensatory mechanisms that might mask phenotypes in complete knockout models.

What methodologies are recommended for analyzing the subcellular localization of mouse UPF0694 transmembrane protein?

As a transmembrane protein, determining the precise subcellular localization of mouse UPF0694 is critical for understanding its function. Recommended approaches include:

• Immunofluorescence microscopy: Using validated antibodies at dilutions of 1:50-1:500 , coupled with markers for specific cellular compartments (ER, Golgi, plasma membrane, endosomes).

• Subcellular fractionation: Differential centrifugation followed by Western blot analysis of distinct cellular fractions can biochemically validate microscopy findings.

• Live-cell imaging: For dynamic localization studies, fusion constructs with fluorescent proteins (preferably small tags like mNeonGreen or HaloTag to minimize disruption of trafficking signals) can track protein movement in real time.

• Super-resolution microscopy techniques: STED, PALM, or STORM microscopy provides nanoscale resolution of membrane protein organization that may reveal functional clustering or segregation within membrane microdomains.

These techniques should be used complementarily, as each has inherent limitations when applied to transmembrane proteins.

How does mouse UPF0694 transmembrane protein C14orf109 homolog compare structurally and functionally to its homologs in other species?

Comparative analysis reveals conservation patterns that may highlight functionally important domains of UPF0694 transmembrane protein across species:

This conservation across vertebrate species suggests fundamental biological roles for this protein. The availability of recombinant proteins from multiple species facilitates comparative studies that may illuminate functional evolution .

When designing experiments using the mouse protein as a model for human disease or biological processes, researchers should consider both the high degree of conservation and potential species-specific differences in regulation or interaction partners.

What are the most effective approaches for comparing expression patterns of this protein across different tissues and developmental stages?

To comprehensively analyze expression patterns of mouse UPF0694 transmembrane protein across tissues and developmental stages, researchers should employ complementary methodologies:

• Transcriptomic analysis:

  • RNA-seq data from public repositories (GEO, ArrayExpress)

  • Single-cell RNA-seq for cellular resolution of expression patterns

  • Developmental time-course analyses to capture temporal dynamics

• Protein-level detection:

  • Western blotting of tissue lysates using validated antibodies

  • Immunohistochemistry on tissue sections for spatial resolution

  • Quantitative proteomics approaches (e.g., SRM/MRM mass spectrometry)

• Reporter systems:

  • Knock-in fluorescent reporters under native promoter control

  • Transgenic mice expressing Cre-recombinase under the D230037D09Rik promoter

These approaches provide complementary information, as transcriptomic data may not perfectly correlate with protein abundance due to post-transcriptional regulation. Particular attention should be paid to membrane protein extraction methods when analyzing protein levels, as standard protocols may inadequately solubilize transmembrane proteins.

What are common challenges in working with recombinant transmembrane proteins like mouse UPF0694, and how can researchers address them?

Transmembrane proteins present unique experimental challenges that researchers should anticipate:

• Solubility issues: The hydrophobic transmembrane domains often lead to aggregation or precipitation.

  • Solution: Include appropriate detergents (DDM, CHAPS) or lipid nanodiscs during purification and storage

  • Consider fusion partners that enhance solubility (MBP, SUMO)

• Proper folding: Ensuring correct protein folding in recombinant expression systems.

  • Solution: Evaluate multiple expression systems including mammalian or insect cells for complex transmembrane proteins

  • Consider membrane-mimetic environments during purification and storage

• Low expression yields: Membrane proteins often express at lower levels than soluble proteins.

  • Solution: Optimize codon usage for expression host

  • Consider inducible systems with lower expression rates to allow proper membrane insertion

• Protein degradation: Increased susceptibility to proteolysis during purification.

  • Solution: Include protease inhibitors throughout purification

  • Maintain low temperatures during processing

  • Consider purification strategies that minimize time required

For mouse UPF0694 transmembrane protein specifically, the commercially available recombinant protein is supplied at >90% purity , suggesting that these challenges have been addressed in its production process.

How can researchers validate the proper folding and activity of recombinant mouse UPF0694 transmembrane protein?

Since the specific biological activity of mouse UPF0694 transmembrane protein is not well-characterized in the provided search results, researchers should consider the following approaches to validate proper folding and functionality:

• Circular dichroism (CD) spectroscopy: Analyze secondary structure content to confirm proper folding of the recombinant protein.

• Thermal shift assays: Evaluate protein stability under different buffer conditions to optimize storage and experimental parameters.

• Functional reconstitution: Incorporate the purified protein into liposomes or nanodiscs to analyze potential transport or signaling activities.

• Binding assays: If interaction partners are identified, validate binding using techniques such as surface plasmon resonance (SPR) or microscale thermophoresis (MST).

• Complementation assays: Express the recombinant protein in knockout cell lines to assess functional rescue of phenotypes.

These approaches collectively provide evidence for proper folding and biological activity, even when specific enzymatic or signaling functions remain to be fully characterized.

What are potential applications of recombinant mouse UPF0694 transmembrane protein in broader research contexts?

While the specific function of mouse UPF0694 transmembrane protein remains to be fully characterized, the recombinant protein has several potential applications in research:

• Antibody validation: As a positive control for validating the specificity of antibodies targeting D230037D09Rik in immunological assays .

• Structural biology: As a starting material for crystallization trials or cryo-EM studies to determine high-resolution structures of this evolutionarily conserved transmembrane protein.

• Protein-protein interaction studies: As bait in pull-down assays to identify novel interaction partners that might illuminate the protein's biological function.

• Development of research tools: As an immunogen for generating new monoclonal antibodies with improved specificity or altered epitope recognition.

• Comparative biology: For cross-species studies investigating evolutionary conservation of UPF0694 transmembrane protein structure and function.

The availability of recombinant proteins from multiple species, including mouse, human, and others , facilitates these comparative approaches.

How might researchers investigate potential roles of mouse UPF0694 transmembrane protein in disease models?

To explore possible roles of mouse UPF0694 transmembrane protein in disease processes, researchers could pursue the following strategies:

• Expression analysis in disease models: Examine changes in D230037D09Rik expression in mouse models of relevant diseases, particularly those involving cellular membranes, trafficking, or signaling.

• Genetic association studies: Analyze whether polymorphisms in the mouse gene correlate with disease susceptibility or progression in mouse genetic reference populations.

• CRISPR-based screens: Include D230037D09Rik in genome-wide or focused CRISPR screens examining disease-relevant phenotypes.

• Tissue-specific conditional knockout models: Generate mouse models with tissue-specific deletion of D230037D09Rik to examine physiological consequences in specific organ systems.

• Translational relevance: Investigate whether findings in mouse models translate to human pathophysiology by examining the human homolog TMEM251 in relevant patient samples or human cell models.

When designing these studies, researchers should consider potential functional redundancy with related proteins and the possibility of compensatory mechanisms in complete knockout models.