Recombinant Macaca fascicularis Vesicle-trafficking protein SEC22a (SEC22A)

How should recombinant Macaca fascicularis SEC22A protein be stored and handled?

For optimal stability and activity, recombinant Macaca fascicularis SEC22A protein should be stored following these guidelines:

• Upon receipt, briefly centrifuge the vial to bring contents to the bottom

• Reconstitute lyophilized protein 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)

• Aliquot the reconstituted protein to avoid repeated freeze-thaw cycles

• Store working aliquots at 4°C for up to one week

• For long-term storage, keep at -20°C/-80°C in the storage buffer (Tris/PBS-based buffer, 6% Trehalose, pH 8.0)

Repeated freezing and thawing should be avoided as this can lead to protein denaturation and loss of activity .

What expression systems are used to produce recombinant Macaca fascicularis SEC22A?

The recombinant Macaca fascicularis SEC22A protein is typically expressed in E. coli expression systems. The protein product described in the search results features the full-length protein (amino acids 1-307) fused to an N-terminal His tag to facilitate purification . Other potential expression systems that could be explored include:

• Mammalian cell lines (for native folding and post-translational modifications)

• Insect cell systems (for higher eukaryotic protein processing)

• Yeast expression systems (for cost-effective eukaryotic expression)

The choice of expression system depends on research requirements for protein folding, post-translational modifications, and downstream applications .

What regulatory guidelines apply to research involving recombinant Macaca fascicularis proteins?

Research involving recombinant Macaca fascicularis proteins is subject to the NIH Guidelines for Research Involving Recombinant or Synthetic Nucleic Acid Molecules, which specify biosafety practices and containment principles. Key regulatory considerations include:

• Institutional Biosafety Committee (IBC) approval may be required depending on the nature of the research

• Compliance is mandatory for all recombinant or synthetic nucleic acid research conducted within the United States at institutions receiving NIH support

• Specific containment measures must be implemented based on risk assessment

• For research conducted abroad, compliance with host country rules is required, or if none exist, approval by an NIH-approved IBC equivalent and acceptance by the host country's governmental authority

Researchers must ensure that all experimental work with recombinant proteins complies with these guidelines, regardless of funding source, if conducted at an institution receiving NIH funding for recombinant research .

How does the structure-function relationship of Macaca fascicularis SEC22A compare to human SEC22A?

The structure-function relationship between Macaca fascicularis SEC22A and human SEC22A reveals high conservation, reflecting their evolutionary proximity. Although the search results don't provide direct comparison data, analysis of the protein sequences suggests:

The high degree of conservation suggests that research findings from Macaca fascicularis SEC22A could have translational relevance to human vesicle trafficking studies, making it a valuable model for investigating human vesicular transport mechanisms and related pathologies .

What are the methodological considerations for assessing SEC22A protein-protein interactions?

When investigating SEC22A protein-protein interactions, researchers should consider the following methodological approaches:

• Co-immunoprecipitation (Co-IP):

  • Use anti-His antibodies to pull down His-tagged SEC22A

  • Western blot with antibodies against potential interacting partners

  • Include appropriate controls (IgG control, input lysate)

• Proximity Ligation Assays:

  • Useful for detecting interactions in fixed cells

  • Requires specific antibodies against SEC22A and binding partners

  • Provides spatial information about interaction sites

• Yeast Two-Hybrid Screening:

  • Construct SEC22A bait plasmids using the full sequence from positions 1-307

  • Screen against cDNA libraries from relevant tissues

  • Validate hits with secondary assays like Co-IP

• Bioluminescence Resonance Energy Transfer (BRET):

  • Tag SEC22A with luciferase donor

  • Tag potential partners with fluorescent acceptor proteins

  • Monitor energy transfer as indicator of proximity/interaction

• Surface Plasmon Resonance:

  • Immobilize purified His-tagged SEC22A on sensor chips

  • Assess binding kinetics with potential partners

  • Determine association/dissociation constants

These methods should be selected based on the specific research question, available resources, and whether the investigation focuses on known or novel interactions .

What are the critical factors for successful functional assays using recombinant Macaca fascicularis SEC22A?

Successful functional assays using recombinant Macaca fascicularis SEC22A require careful consideration of several critical factors:

• Protein Quality Assessment:

  • Verify protein purity (>90%) using SDS-PAGE

  • Confirm identity via Western blot with anti-His and anti-SEC22A antibodies

  • Assess proper folding with circular dichroism spectroscopy

• Buffer Optimization:

  • Test multiple buffer conditions (pH 6.5-8.0)

  • Evaluate salt concentration effects (150-300 mM NaCl)

  • Consider including stabilizing agents (5-10% glycerol, 1-2 mM DTT)

• Vesicle Trafficking Assays:

  • Establish baseline vesicle formation using fluorescent lipid markers

  • Compare SNARE complex formation efficiency with wild-type controls

  • Measure membrane fusion events quantitatively

• Cellular Models Selection:

  • Consider species compatibility in heterologous systems

  • Use cell lines with low endogenous SEC22A expression

  • Validate with siRNA knockdown of endogenous protein

• Data Analysis Parameters:

  • Include appropriate statistical tests based on data distribution

  • Establish dose-response relationships where applicable

  • Document time-dependent effects on vesicle transport

The storage and reconstitution procedures described earlier (maintaining protein in Tris/PBS buffer with 6% trehalose at pH 8.0) provide a starting point, but optimization for specific assay conditions may be necessary .

How can researchers troubleshoot low activity of recombinant Macaca fascicularis SEC22A in membrane fusion assays?

When encountering low activity of recombinant Macaca fascicularis SEC22A in membrane fusion assays, researchers should implement the following troubleshooting strategies:

• Protein Integrity Assessment:

  • Perform mass spectrometry to confirm full-length protein (307 amino acids)

  • Check for degradation using fresh Western blot analysis

  • Verify His-tag accessibility with anti-His antibodies

• Reconstitution Protocol Optimization:

  • Adjust protein:lipid ratios (typically test 1:100, 1:200, and 1:500)

  • Try different membrane compositions (include 1-5% PI(4,5)P2 or other regulatory lipids)

  • Vary the protocol for proteoliposome formation (detergent dialysis vs. direct incorporation)

• Binding Partner Availability:

  • Ensure presence of all necessary SNARE complex components

  • Verify activity of binding partners independently

  • Test with excess concentrations of cognate SNAREs

• Assay Condition Adjustments:

  • Modify calcium concentration (0-2 mM range)

  • Test temperature dependence (25°C vs. 37°C)

  • Adjust incubation times to capture slower kinetics

• Alternative Fusion Detection Methods:

  • If using lipid mixing assays, try content mixing assays as alternative

  • Consider single-vesicle fusion assays for higher sensitivity

  • Implement FRET-based approaches with different fluorophore pairs

A methodical approach to these potential issues can help identify the specific factors limiting SEC22A activity in membrane fusion assays .

What considerations should be made when comparing results between recombinant SEC22A from different macaque species?

When comparing results between recombinant SEC22A from different macaque species (such as Macaca fascicularis and Macaca mulatta), researchers should consider several important factors:

• Sequence Variation Analysis:

  • Perform detailed alignment of the full 307 amino acid sequences

  • Identify non-conservative substitutions that might affect function

  • Pay special attention to functional domains (SNARE motif, transmembrane region)

• Expression System Consistency:

  • Ensure both proteins are expressed in the same system (e.g., both in E. coli)

  • Use identical tags (position and type) for fair comparison

  • Apply consistent purification protocols

• Evolutionary Context:

  • Consider the evolutionary distance between species

  • Relate observed functional differences to known speciation events

  • Compare to human SEC22A to establish translational relevance

• Experimental Design Controls:

  • Include both proteins in each experimental batch

  • Normalize activity based on protein concentration and purity

  • Use multiple assay systems to confirm observed differences

• Statistical Analysis Requirements:

  • Determine appropriate sample sizes for detecting inter-species differences

  • Apply paired statistical tests when possible

  • Report effect sizes along with p-values for meaningful interpretation

This comparative approach can provide insights into species-specific adaptations in vesicular trafficking systems while minimizing methodological artifacts .

What is the optimal method for transfecting Macaca fascicularis cell lines with SEC22A constructs?

For transfecting Macaca fascicularis cell lines with SEC22A constructs, researchers should consider several optimization strategies:

• Cell Line-Specific Protocol Development:

  • For primary Macaca fascicularis cells: Nucleofection often yields higher efficiency than lipid-based methods

  • For established Macaca fascicularis cell lines: Lipofectamine 3000 or similar lipid reagents typically work well

  • For difficult-to-transfect cells: Viral vector systems (lentivirus) may be necessary

• Transfection Optimization Matrix:

  Method	DNA:Reagent Ratio	Cell Density	Recovery Time	Typical Efficiency
  Lipofection	1:2, 1:3, 1:4	70-90%	24-48 hours	40-60%
  Electroporation	2-5 μg DNA/106 cells	1-5×106/mL	48-72 hours	50-70%
  Nucleofection	2 μg DNA/106 cells	2×106/sample	48 hours	60-80%
  Viral transduction	MOI 1-10	50-70%	72 hours	70-90%

• Construct Design Considerations:

  • Optimize codon usage for Macaca fascicularis

  • Include species-appropriate promoters (e.g., CMV or EF1α)

  • Consider including a fluorescent reporter for transfection monitoring

• Verification Methods:

  • Western blot using anti-SEC22A or anti-tag antibodies

  • Immunofluorescence to assess subcellular localization

  • qRT-PCR to measure transcript levels

• Stable Line Generation Protocol:

  • Select appropriate antibiotic based on construct resistance marker

  • Begin selection 48-72 hours post-transfection

  • Isolate single colonies to establish clonal lines

  • Validate SEC22A expression levels across multiple passages

These methodological approaches should be adapted based on the specific Macaca fascicularis cell line and experimental requirements .

How can researchers establish reliable in vitro assays to measure SEC22A-mediated vesicle fusion?

Establishing reliable in vitro assays to measure SEC22A-mediated vesicle fusion requires careful consideration of multiple technical parameters:

• Reconstituted Proteoliposome System Setup:

  • Prepare donor vesicles containing purified recombinant Macaca fascicularis SEC22A (1:200 protein:lipid ratio)

  • Incorporate fluorescent lipids (e.g., NBD-PE, Rhodamine-PE) at 1.5 mol% for FRET-based assays

  • Prepare acceptor vesicles with cognate SNARE proteins

• Fusion Assay Protocol Development:

  • Monitor lipid mixing through fluorescence dequenching

  • Measure content mixing using self-quenching fluorescent dyes

  • Record fusion kinetics at physiological temperature (37°C)

  • Include controls with protein-free vesicles and with cytoplasmic domain fragments

• Assay Validation Criteria:

  • Demonstrate dependence on SEC22A:cognate SNARE stoichiometry

  • Show specificity through competition experiments

  • Verify calcium dependence or independence

  • Confirm sensitivity to known inhibitors

• Quantification Methods:

  • Calculate fusion efficiency as percentage of maximum fluorescence

  • Determine initial fusion rates from linear portions of kinetic curves

  • Apply appropriate curve fitting for kinetic parameters extraction

• Advanced Approaches:

  • Single-vesicle fusion assays using total internal reflection fluorescence microscopy

  • Multi-color fluorescence microscopy to distinguish docking from fusion

  • Cryo-electron microscopy to visualize fusion intermediates

The reliable reconstruction of SEC22A-mediated fusion requires highly pure protein (>90% purity) with confirmed activity, carefully prepared proteoliposomes, and robust detection systems .

What controls are essential when studying the impact of SEC22A mutations on vesicular trafficking?

When studying the impact of SEC22A mutations on vesicular trafficking, the following essential controls should be implemented:

• Genetic Controls:

  • Wild-type SEC22A expression construct (positive control)

  • Empty vector transfection (negative control)

  • Known trafficking-defective SEC22A mutant (reference control)

  • Silent mutations maintaining amino acid sequence (technical control)

• Expression Level Controls:

  • Quantitative Western blot to ensure comparable expression levels

  • Inducible expression systems to test dose-dependent effects

  • siRNA knockdown of endogenous SEC22A with rescue constructs

• Localization Controls:

  • Co-localization with established organelle markers:

    Organelle	Recommended Markers
    ER	Calnexin, PDI
    ERGIC	ERGIC-53
    Golgi	GM130, TGN46
    Endosomes	Rab5, Rab7
    Plasma membrane	Na+/K+ ATPase

  • Live-cell imaging with photoactivatable constructs

• Functional Assays Controls:

  • Cargo transport rates in cells with normal SEC22A levels

  • Temperature blocks to synchronize trafficking (e.g., 15°C, 20°C blocks)

  • Pharmacological controls (Brefeldin A, nocodazole) to validate assay sensitivity

• Interaction Partner Controls:

  • Pull-down assays with established binding partners

  • Competition assays with soluble fragments

  • Domain swaps to map functional regions

These comprehensive controls help distinguish specific mutational effects from artifacts and provide a framework for interpreting changes in vesicular trafficking dynamics .

How can Macaca fascicularis SEC22A be used as a model for studying human vesicular trafficking disorders?

Macaca fascicularis SEC22A serves as an excellent model for studying human vesicular trafficking disorders due to several key advantages:

• Evolutionary Proximity and Translational Relevance:

  • High sequence homology between Macaca fascicularis and human SEC22A

  • Conserved functional domains and regulatory mechanisms

  • Similar cellular pathways and trafficking machinery

• Disease Modeling Applications:

  • Neurodegenerative disorders with trafficking defects (Alzheimer's, Parkinson's)

  • Secretory pathway disorders affecting protein export

  • Lysosomal storage diseases with impaired membrane fusion

• Experimental Approaches:

  • Generate macaque cell lines expressing disease-associated human SEC22A variants

  • Compare trafficking dynamics between wild-type and mutant proteins

  • Test therapeutic compounds targeting SEC22A-dependent pathways

  • Develop animal models with engineered SEC22A modifications

• Comparative Studies Framework:

  Study Type	Macaca fascicularis Model	Human System
  Cellular	Primary fibroblasts, neurons	Patient-derived cells
  Tissue	Ex vivo tissue slices	Postmortem tissue
  In vivo	Transgenic models	Clinical observations
  Molecular	Recombinant protein studies	Patient protein variants

• Biomarker Development Potential:

  • Identify SEC22A-dependent trafficking events as disease indicators

  • Develop assays measuring SEC22A complex formation efficiency

  • Screen for molecules modulating SEC22A function

The close phylogenetic relationship between macaques and humans makes Macaca fascicularis SEC22A particularly valuable for translational research into trafficking-related human diseases .

What emerging technologies are advancing the study of SEC22A and other vesicle trafficking proteins?

Several cutting-edge technologies are transforming research on SEC22A and other vesicle trafficking proteins:

• Advanced Imaging Techniques:

  • Super-resolution microscopy (STORM, PALM) achieving 20-30 nm resolution

  • Lattice light-sheet microscopy for extended live-cell imaging

  • Correlative light and electron microscopy (CLEM) connecting dynamics to ultrastructure

  • Label-free techniques reducing artifacts from fluorescent tags

• Genome Engineering Approaches:

  • CRISPR-Cas9 for endogenous SEC22A tagging and mutation

  • Base editing for precise single nucleotide modifications

  • Conditional knockout systems for temporal control

  • High-throughput screening of trafficking phenotypes

• Proteomics Innovations:

  • Proximity labeling (BioID, APEX) for identifying transient interactions

  • Crosslinking mass spectrometry for structural interaction mapping

  • Single-cell proteomics revealing cell-to-cell variation

  • Targeted proteomics quantifying SEC22A complex stoichiometry

• Artificial Intelligence Applications:

  • Machine learning for vesicle tracking and fusion event detection

  • Deep learning classifying trafficking defects in high-content imaging

  • Predictive modeling of mutation effects on SEC22A function

  • Systems biology approaches integrating multi-omics data

• Organoid and Microphysiological Systems:

  • Macaque brain organoids for studying neuronal trafficking

  • Organ-on-chip models incorporating trafficking readouts

  • Patient-derived organoids for disease modeling

  • Multi-tissue systems capturing inter-organ trafficking dynamics

These technological advances are enabling unprecedented insights into the spatial and temporal dynamics of SEC22A-mediated vesicular trafficking and its dysregulation in disease states .

How does the regulation of SEC22A differ between normal and pathological conditions?

The regulation of SEC22A in normal versus pathological conditions reveals important differences that may contribute to disease mechanisms:

• Transcriptional Regulation Differences:

  • Normal: Baseline expression maintained by housekeeping promoters

  • Pathological: Altered expression in response to ER stress and unfolded protein response

  • Key transcription factors affecting SEC22A expression include XBP1 and ATF6

• Post-translational Modification Patterns:

  • Normal: Regulated phosphorylation at specific residues

  • Pathological: Hyperphosphorylation or aberrant modification patterns

  • Modification sites presumed to be conserved between human and Macaca fascicularis

• Protein-Protein Interaction Changes:

  Condition	Interaction Partner	Effect on SEC22A Function
  Normal	Cognate SNAREs	Productive fusion complex formation
  ER Stress	BiP/GRP78	Sequestration and reduced activity
  Inflammation	Inflammatory mediators	Altered trafficking dynamics
  Neurodegenerative	Misfolded proteins	Impaired complex assembly

• Subcellular Localization Shifts:

  • Normal: Dynamic cycling between ER, ERGIC, and Golgi

  • Pathological: Accumulation in specific compartments or inclusion bodies

  • Altered ratios between membrane-bound and cytosolic pools

• Functional Consequences:

  • Normal: Balanced anterograde and retrograde transport

  • Pathological: Compromised secretory pathway efficiency

  • Downstream effects on protein homeostasis and cellular stress responses

These differential regulatory mechanisms highlight potential therapeutic targets for diseases involving vesicular trafficking defects, with the recombinant Macaca fascicularis SEC22A serving as a valuable tool for mechanistic studies and drug screening .

What are the key considerations for researchers starting work with recombinant Macaca fascicularis SEC22A?

Researchers beginning work with recombinant Macaca fascicularis SEC22A should consider these essential guidelines:

• Experimental Planning:

  • Define clear research questions addressing specific aspects of SEC22A function

  • Design experiments with appropriate controls (see section 3.3)

  • Consider comparative studies with human SEC22A for translational relevance

  • Obtain necessary regulatory approvals per NIH guidelines for recombinant research

• Technical Considerations:

  • Choose expression systems based on experimental requirements (bacterial for quantity, mammalian for native folding)

  • Optimize purification strategies to maintain protein activity

  • Implement proper storage protocols (aliquoting with 50% glycerol, storage at -80°C)

  • Validate protein quality before functional assays (SDS-PAGE, Western blot)

• Methodological Approach:

  • Begin with established assays before developing novel methods

  • Incorporate both in vitro and cellular systems for comprehensive analysis

  • Consider multiple detection methods for cross-validation

  • Document detailed protocols for reproducibility

• Common Pitfalls to Avoid:

  • Neglecting protein quality assessment before functional studies

  • Using inappropriate buffer conditions affecting protein stability

  • Overlooking species-specific differences in interacting partners

  • Failing to account for tag effects on protein function

• Resources and Collaboration:

  • Engage with established vesicular trafficking research groups

  • Access repositories of validated constructs and cell lines

  • Consider multi-disciplinary approaches combining structural, cellular, and systems biology

By addressing these considerations from the outset, researchers can establish robust experimental systems for investigating SEC22A function in vesicular trafficking pathways .

What are the most promising future research directions for understanding SEC22A function and regulation?

The most promising future research directions for advancing our understanding of SEC22A function and regulation include:

• Integrative Structural Biology Approaches:

  • Cryo-electron microscopy of SEC22A in SNARE complexes

  • Hydrogen-deuterium exchange mass spectrometry for conformational dynamics

  • Molecular dynamics simulations of membrane insertion and fusion

  • Single-molecule studies of SNARE complex assembly kinetics

• Systems-Level Understanding:

  • Comprehensive interactome mapping across different cell types

  • Multi-omics integration (transcriptomics, proteomics, metabolomics)

  • Network analysis of SEC22A within trafficking pathways

  • Computational modeling of vesicle budding, transport, and fusion

• Disease-Relevant Investigations:

  • Role in neurodegenerative disorders with trafficking defects

  • Impact on immune cell function and inflammatory responses

  • Contribution to secretory pathway stress in metabolic diseases

  • SEC22A variants associated with human pathologies

• Therapeutic Development Opportunities:

  • Small molecule modulators of SEC22A function

  • Targeted degradation approaches for overexpressed SEC22A

  • Gene therapy strategies for SEC22A-related disorders

  • Biomarker development based on SEC22A complexes

• Evolutionary and Comparative Studies:

  • Functional divergence between primate SEC22A homologs

  • Cell-type specific variations in SEC22A regulation

  • Environmental influences on SEC22A-dependent trafficking

  • Specialized roles in tissues with high secretory demands

These research directions represent the frontier of SEC22A biology and offer promising avenues for translating molecular insights into clinical applications for trafficking-related disorders .

How can researchers effectively troubleshoot and optimize experiments with recombinant Macaca fascicularis SEC22A?

To effectively troubleshoot and optimize experiments with recombinant Macaca fascicularis SEC22A, researchers should implement this systematic approach:

• Protein Quality Assessment Workflow:

  • Run fresh SDS-PAGE to check purity and integrity

  • Verify identity with Western blot using anti-SEC22A antibodies

  • Assess aggregation state with size exclusion chromatography

  • If quality issues persist, optimize expression conditions (temperature, induction time)

• Common Issues and Solutions Matrix:

  Issue	Potential Causes	Troubleshooting Steps
  Low yield	Expression problems	Optimize codon usage, lower induction temperature
  Protein inactivity	Misfolding	Try refolding protocols, mammalian expression
  Aggregation	Hydrophobic regions	Add detergents, optimize salt concentration
  Poor binding	Buffer incompatibility	Test pH range, add stabilizing agents
  Variable results	Protocol inconsistency	Develop detailed SOP, control for lot variation

• Advanced Troubleshooting Techniques:

  • Thermal shift assays to optimize buffer stability

  • Limited proteolysis to identify flexible/unstable regions

  • Cross-validation with orthogonal assay systems

  • Pilot experiments with small-scale optimization matrices

• Documentation and Knowledge Management:

  • Maintain detailed lab notebooks with all parameters

  • Create troubleshooting knowledge base

  • Develop standardized quality control metrics

  • Establish go/no-go criteria for experimental progression

This systematic approach allows researchers to efficiently identify and address experimental challenges while optimizing protocols for consistent, high-quality results with recombinant Macaca fascicularis SEC22A .