Recombinant Danio rerio Transmembrane protein 85 (tmem85)

What are the recommended storage conditions for tmem85 protein?

For optimal stability and activity retention, the recombinant protein should be stored at -20°C/-80°C upon receipt. Aliquoting is necessary for multiple use to avoid repeated freeze-thaw cycles, which can degrade protein quality. For working solutions, store aliquots at 4°C for up to one week. The protein is typically provided in a storage buffer containing Tris/PBS with 50% glycerol at pH 8.0 or similar optimal conditions. When reconstituting lyophilized protein, use deionized sterile water to achieve a concentration of 0.1-1.0 mg/mL, and consider adding glycerol (5-50% final concentration) for long-term storage .

What is the UniProt identifier and genomic information for tmem85?

The UniProt identifier for Danio rerio tmem85 is Q6P011. The gene is also known as emc4 or zgc:77852. Additional identifiers include:

• KEGG: dre:402956

• STRING: 7955.ENSDARP00000108649

• UniGene: Dr.82273

These identifiers are valuable for bioinformatic analyses and accessing further information about conserved domains, evolutionary relationships, and functional predictions .

Why is the zebrafish (Danio rerio) a valuable model for studying tmem85 function?

Zebrafish has emerged as a powerful vertebrate model for investigating protein functions due to several advantages:

• Extensive sequence and functional conservation with the human genome

• Optical transparency in larvae enabling high-resolution visualization

• Fully sequenced and annotated genome

• Advanced forward and reverse genetic tools (including TALEN-mediated gene knockout)

• Suitability for chemical screening studies

Particularly for immune-related studies, zebrafish larvae rely exclusively on innate immune responses during early development (before 4-6 weeks post-fertilization), providing a unique opportunity to examine mechanisms without the confounding effects of adaptive immunity. This makes zebrafish ideal for studying transmembrane proteins like tmem85 that may participate in fundamental cellular processes .

What experimental applications is recombinant tmem85 suitable for?

• Developing and validating antibodies against tmem85

• Protein-protein interaction studies

• Functional assays to determine biological activity

• Structural studies

• As a positive control in expression studies

The high purity (>90% as determined by SDS-PAGE) makes it suitable for sensitive applications requiring minimal contaminants .

What considerations should be taken into account when designing experiments with recombinant tmem85?

When designing experiments with recombinant tmem85, researchers should consider:

How can I optimize reconstitution of lyophilized tmem85 for maximum activity?

To optimize reconstitution of lyophilized tmem85:

• Briefly centrifuge the vial prior to opening to bring contents to the bottom

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

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

• Mix gently to ensure complete dissolution without introducing bubbles or causing protein denaturation

• Aliquot immediately to avoid repeated freeze-thaw cycles

• Validate protein activity using appropriate functional assays before proceeding with experiments

What statistical approaches are recommended for analyzing experimental data with potential confounding variables?

When analyzing experimental data involving recombinant proteins like tmem85 where multiple variables might influence results:

How can I investigate the role of tmem85 in oxidative stress responses using zebrafish models?

Investigating tmem85's role in oxidative stress responses can leverage several advanced approaches:

• Transgenic Reporter Systems: Generate transgenic zebrafish expressing genetically-encoded sensors for reactive oxygen species (ROS) in tmem85 wildtype and knockout/knockdown backgrounds. For instance, the HyPer probe, consisting of circularly permuted YFP inserted in the regulatory domain of OxyR, allows visualization of H₂O₂ with high sensitivity and can reveal spatial and temporal relationships between tmem85 and oxidative stress responses .

• Redox-Sensitive Transcription Factor Analysis: Examine how tmem85 affects transcription factors involved in oxidative stress responses, such as NRF2 (Nuclear factor E2-related factor 2). NRF2 regulates antioxidant gene expression via interaction with antioxidant/electrophile response elements (ARE/EPRE). Like HIF-α, under normal redox conditions, NRF2 is associated with a repressor protein (KEAP1) .

• In vivo Inflammation Models: Use zebrafish larvae to study the connection between tmem85, oxidative mechanisms, and inflammatory processes. This can be particularly valuable for understanding early developmental stages relevant to chronic conditions .

• Real-time Imaging: Leverage the optical transparency of zebrafish larvae for high-resolution visualization of dynamic processes related to tmem85 function under oxidative stress conditions .

What approaches can be used to study tmem85's potential role in innate immune responses?

To investigate tmem85's potential role in innate immune responses:

• Pattern Recognition Receptor (PRR) Pathway Analysis: Examine whether tmem85 interacts with or influences key PRR pathways, including Toll-like receptors (TLRs), RIG-I-like receptors (RLRs), and NOD-like receptors (NLRs), which are well-conserved in zebrafish .

• Bacterial Challenge Models: Use established zebrafish infection models with pathogens like Pseudomonas aeruginosa, Staphylococcus aureus, or Clostridioides difficile to assess whether tmem85 affects susceptibility, bacterial clearance, or inflammatory responses .

• Neutrophil Recruitment and Function: Analyze neutrophil migration and activity in response to inflammatory stimuli in tmem85-deficient zebrafish. This could reveal roles in chemotaxis, ROS production, or cytokine release .

• Morpholino Knockdown and TALEN-mediated Knockout: Create tmem85-deficient zebrafish using morpholino-based knockdown (for transient effects) or TALEN-mediated gene editing (for stable genetic models) to study loss-of-function phenotypes .

• Pro-inflammatory Cytokine Analysis: Measure expression of key cytokines like IL-1β, IL-6, and IL-8 in tmem85-modified zebrafish to identify potential roles in cytokine production or regulation .

What are the methodological considerations for investigating protein-protein interactions involving tmem85?

When investigating protein-protein interactions of tmem85:

• Membrane Protein Considerations: As a transmembrane protein, tmem85 requires specialized approaches for interaction studies. Consider using mild detergents or membrane-mimetic systems to maintain native conformation during isolation and analysis.

• Validation Through Multiple Methods: Employ complementary approaches such as:

  • Co-immunoprecipitation with tagged recombinant tmem85

  • Proximity ligation assays in cell culture systems

  • FRET/BRET assays for live-cell interaction dynamics

  • Yeast two-hybrid with specialized membrane protein adaptations

• In vivo Validation: Use zebrafish models with fluorescently tagged proteins to visualize potential interactions in physiologically relevant contexts, taking advantage of the optical transparency of larvae .

• Control for Non-specific Interactions: Transmembrane proteins can form spurious interactions due to hydrophobicity. Include appropriate negative controls and competitor proteins to identify specific interactions.

• Domain Mapping: Generate truncated versions of tmem85 to map specific interaction domains and distinguish functionally relevant interactions from non-specific associations.

How can I address issues with protein stability and activity loss in tmem85 experiments?

To address stability and activity issues:

• Optimize Buffer Conditions: Test different buffer compositions, pH values, and additives to identify conditions that maximize tmem85 stability. Consider including protease inhibitors, reducing agents (if applicable), and stabilizing agents like glycerol.

• Temperature Management: Minimize exposure to room temperature. Keep the protein on ice during experiment preparation and perform assays at the lowest functional temperature.

• Avoid Freeze-Thaw Cycles: Once thawed, avoid refreezing the protein. Prepare multiple small aliquots during initial reconstitution .

• Validate Protein Quality: Before proceeding with experiments, confirm protein integrity by SDS-PAGE and, if possible, activity assays specific to the expected function of tmem85.

• Storage Concentration Optimization: Higher protein concentrations may improve stability. Consider concentrating the protein if dilute solutions show rapid activity loss .

What are the methodological considerations for resolving experimental contradictions when studying tmem85?

When faced with contradictory experimental results: