Recombinant Pan troglodytes Tetraspanin-7 (TSPAN7)

What is the structural and functional characterization of TSPAN7?

TSPAN7 belongs to the transmembrane 4 superfamily (tetraspanin family), characterized by four hydrophobic transmembrane domains. Most members of this family are cell-surface proteins that function in signal transduction pathways . TSPAN7 functions as a cell surface glycoprotein that forms complexes with integrins and may play a crucial role in controlling neurite outgrowth .

The protein consists of:

• Four transmembrane domains

• Two extracellular loops with conserved cysteine residues

• Short intracellular N- and C-terminal domains

Human recombinant TSPAN7 segments (such as Arg113-Met213) have a molecular mass of approximately 12.6-13.63 kDa, which may appear as 13.5-18 kDa on SDS-PAGE under reducing conditions when expressed with a His tag .

How does Pan troglodytes TSPAN7 compare to human TSPAN7?

While the search results primarily focus on human TSPAN7, researchers should be aware of the important comparative aspects when working with Pan troglodytes (chimpanzee) TSPAN7:

• Sequence homology: Due to the high genetic similarity between humans and chimpanzees (98-99%), TSPAN7 likely shares significant sequence conservation, particularly in functional domains.

• Experimental considerations:

  • Antibody cross-reactivity should be validated when using human-targeted antibodies for chimpanzee TSPAN7

  • Species-specific post-translational modifications may affect protein function

  • Binding partners may have subtle differences affecting interaction strength or specificity

• Comparative analysis approach:

  • Sequence alignment to identify conserved versus divergent regions

  • Functional assays comparing binding properties and signaling outcomes

  • Expression pattern analysis across tissues in both species

What are the primary biological roles of TSPAN7?

TSPAN7 has several important biological functions that make it a significant research target:

• Neurological function:

  • Associated with X-linked mental retardation and neuropsychiatric diseases including Huntington's chorea, fragile X syndrome, and myotonic dystrophy

  • Plays a role in neurite outgrowth, suggesting importance in neuronal development

• Signal transduction:

  • Mediates signaling events that regulate cell development, activation, growth, and motility

  • Forms complexes with integrins, potentially affecting cell adhesion and migration

• Cancer biology:

  • Decreases in high-grade gliomas, with low expression associated with poor prognosis

  • May function as a tumor suppressor by inhibiting glioma progression

• Immune function:

  • Recently identified as a key immune system target in type 1 diabetes

  • May have unexplored roles in immune cell function and regulation

What are optimal methods for detecting TSPAN7 expression in tissue samples?

Multiple complementary approaches can be employed for reliable TSPAN7 detection:

• Quantitative Real-Time PCR (qRT-PCR):

  • RNA extraction method: TRIzol-based extraction followed by RNA extraction kit

  • Example primer sequences (human TSPAN7):

    • Forward: 5'-STATCCTTCGTCTTCGGATC-3'

    • Reverse: 5'-CATACAGTTTCAGCATCGG-3'

  • PCR conditions: 95°C for 15 min, followed by 40 cycles of 95°C for 15s and 60°C for 1 min

  • Analysis: Dissolution curve analysis to confirm primer specificity

• Western Blotting:

  • Protein extraction: RIPA lysate with BCA method for concentration determination

  • Electrophoresis: 12% SDS-PAGE at 80V until the minimum molecular weight marker reaches the bottom

  • Transfer conditions: 200mA constant current for 80 minutes to PVDF membrane

  • Detection: Commercial antibodies such as TSPAN7 (abcam, ab211870) have been validated

  • Quantification: ImageJ software for band intensity analysis

• Immunofluorescence/Immunohistochemistry:

  • Fixation: Optimize protocols for membrane proteins to maintain epitope accessibility

  • Controls: Include normal brain tissue as positive control

  • Counterstaining: Nuclear stains to visualize cellular context

What are the production and purification strategies for recombinant TSPAN7?

Production of high-quality recombinant TSPAN7 can be achieved through several expression systems:

• E. coli Expression System:

  • Successfully used for human TSPAN7 (Arg113-Met213) with His tag

  • Advantages: High yield, cost-effective, scalable production

  • Limitations: Lack of post-translational modifications, potential folding issues with membrane proteins

• Insect Cell Expression System:

  • Sf9 insect cells have been effectively used for TSPAN7 production

  • Produces glycosylated polypeptide chain with proper folding

  • More suitable for producing proteins requiring post-translational modifications

• Purification Protocol:

  • Affinity chromatography using His-tag (for His-tagged constructs)

  • Proprietary chromatographic techniques for further purification

  • Quality control by SDS-PAGE (>90% purity achievable)

• Protein Characteristics:

  Property	Specification
  Molecular Mass	12.6-13.63 kDa (13.5-18 kDa on SDS-PAGE)
  Form	Lyophilized powder or frozen liquid
  Purity	>90% as determined by SDS-PAGE
  Concentration	Typically 0.5mg/ml

What are critical considerations for experimental design using recombinant TSPAN7?

When designing experiments with recombinant TSPAN7, researchers should address several key considerations:

• Protein stability and storage:

  • Short-term storage (2-4 weeks): 2-8°C

  • Long-term storage: -20°C to -80°C

  • Avoid repeated freeze-thaw cycles

  • For enhanced stability, add carrier protein (0.1% HSA or BSA)

  • Reconstitute lyophilized protein in sterile water

• Functional validation approaches:

  • Binding assays with known interaction partners (e.g., integrins)

  • Cell-based functional assays (neurite outgrowth, migration)

  • Signaling pathway activation analysis (MAPK pathway)

• Controls and standardization:

  • Include both positive controls (normal brain tissue)

  • Use empty vector controls for overexpression studies

  • Monitor transfection efficiency with fluorescent reporters

  • Employ multiple housekeeping genes/proteins for normalization

• Species considerations:

  • Validate antibody cross-reactivity between human and Pan troglodytes TSPAN7

  • Consider potential functional differences when extrapolating across species

How does TSPAN7 influence neurological function and disorders?

TSPAN7 has significant implications for neurological development and disease:

• Genetic associations:

  • The TSPAN7 gene is associated with X-linked mental retardation (MRX58)

  • Also linked to neuropsychiatric diseases including Huntington's chorea, fragile X syndrome, and myotonic dystrophy

• Neuronal development:

  • May play a crucial role in neurite outgrowth regulation

  • Forms complexes with integrins that potentially influence neuronal migration and adhesion

• Research approaches:

  • Lentiviral overexpression systems to study TSPAN7 function in neuronal cells

  • TSPAN7 knockout/knockdown models to examine loss-of-function effects

  • Protein-protein interaction studies to identify neuronal binding partners

  • Signaling pathway analysis focusing on neuronal differentiation and migration

• Therapeutic implications:

  • Potential target for interventions in neurodevelopmental disorders

  • Modulation of TSPAN7-integrin interactions might influence neuronal connectivity

  • Expression restoration strategies could address TSPAN7 deficiency in genetic disorders

What is the significance of TSPAN7 in cancer biology, particularly gliomas?

Research has revealed important associations between TSPAN7 and cancer progression:

• Expression pattern in gliomas:

  • TSPAN7 expression decreases in high-grade gliomas compared to normal brain tissue

  • Low expression correlates with poor prognosis across multiple datasets

• Prognostic value:

  • Multivariate COX regression analysis identified TSPAN7 as an independent prognostic factor:

    • TCGA dataset: HR = 0.65, p < 0.05

    • CGGA_325 dataset: HR = 0.38, p < 0.001

    • CGGA_693 dataset: HR = 0.58, p < 0.01

• Tumor suppressor function:

  • High TSPAN7 expression appears to inhibit glioma progression

  • As TSPAN7 expression decreases, tumors show more aggressive biological behaviors

• Affected pathways:

  • Low TSPAN7 expression correlates with increased activity in:

    • Cell proliferation pathways

    • Epithelial-mesenchymal transition (EMT)

    • Angiogenesis

    • DNA repair mechanisms

    • MAPK signaling

How does TSPAN7 interact with cellular signaling networks?

TSPAN7's involvement in signal transduction networks is multifaceted:

• Integrin complexes:

  • TSPAN7 forms complexes with integrins at the cell surface

  • These interactions likely occur within tetraspanin-enriched microdomains (TEMs)

  • Complexes may influence cell adhesion, migration, and signaling

• Signal transduction pathways:

  • Mediates signaling events regulating cell development, activation, growth, and motility

  • Inverse relationship with MAPK pathway activation - lower TSPAN7 correlates with increased MAPK signaling

• Cellular process regulation:

  • Influences multiple processes through these signaling interactions:

    • Cell proliferation capacity

    • Epithelial-mesenchymal transition

    • Angiogenesis

    • DNA repair mechanisms

• Research methodologies:

  • Co-immunoprecipitation to identify binding partners

  • Phosphorylation analysis of downstream signaling components

  • Transcriptional profiling to identify regulated gene networks

  • Functional assays measuring cellular responses to TSPAN7 modulation

What are common challenges when working with recombinant TSPAN7?

Researchers should anticipate and address several technical challenges:

• Protein solubility and aggregation:

  • As a membrane protein, TSPAN7 contains hydrophobic domains prone to aggregation

  • Solution: Use appropriate buffers like PBS with 10% glycerol

  • Consider mild detergents for maintaining solubility

• Maintaining native conformation:

  • Extracellular domains with disulfide bonds require proper oxidizing conditions

  • Expression system selection influences proper folding and post-translational modifications

  • Consider non-reducing conditions during purification and analysis

• Tag interference:

  • Common His-tag may affect protein function in some assays

  • Evaluate tag position (N- vs C-terminal) for optimal protein function

  • Consider tag removal for critical functional studies

• Storage stability:

  • Avoid repeated freeze-thaw cycles that reduce activity

  • Aliquot purified protein to minimize freezing/thawing

  • Add carrier proteins (0.1% HSA or BSA) for long-term storage

• Reconstitution issues:

  • For lyophilized proteins, ensure complete dissolution

  • Use gentle mixing rather than vortexing

  • Allow sufficient time for complete rehydration

How can researchers validate functional activity of recombinant TSPAN7?

Multiple approaches ensure recombinant TSPAN7 maintains its biological activity:

• Structural validation:

  • Circular dichroism spectroscopy for secondary structure confirmation

  • Size exclusion chromatography to assess oligomeric state

  • Limited proteolysis to verify proper folding

• Binding assays:

  • Co-immunoprecipitation with known binding partners (integrins)

  • Surface plasmon resonance for interaction kinetics

  • Pull-down assays with cellular extracts to identify binding partners

• Functional assays:

  • Neurite outgrowth assays in neuronal cell models

  • Cell migration/invasion studies

  • Signaling pathway activation, particularly MAPK pathway components

• Comparison with overexpression studies:

  • Lentiviral overexpression systems as positive controls

  • Compare cellular effects of recombinant protein to genetic overexpression

  • Evaluate cellular localization patterns

What essential controls should be included in TSPAN7 studies?

Rigorous controls are critical for reliable TSPAN7 research:

• For gene expression studies (qRT-PCR):

  • Multiple reference genes for normalization

  • No-template controls to detect contamination

  • No-RT controls to detect genomic DNA

  • Primer specificity verification via melt curve analysis

• For protein expression studies (Western blot):

  • Loading controls (GAPDH, β-actin)

  • Positive controls (normal brain tissue)

  • Negative controls (tissues known not to express TSPAN7)

  • Antibody specificity controls

• For functional studies:

  • Empty vector controls for overexpression experiments

  • Fluorescent reporter monitoring for transfection efficiency

  • Dose-response experiments to establish working concentrations

  • Pathway inhibitors to confirm mechanism specificity

• For clinical sample analysis:

  • Matched normal adjacent tissue controls

  • Grade/stage-matched controls

  • Demographic-matched controls

What emerging roles of TSPAN7 in immune function merit investigation?

Recent findings suggest promising directions for TSPAN7 immunology research:

• Type 1 diabetes connection:

  • TSPAN7 has been identified as a key immune system target in type 1 diabetes

  • Potential autoimmune recognition mechanisms require investigation

  • Implications for other autoimmune conditions

• Immune cell expression and function:

  • Expression patterns across immune cell populations

  • Potential roles in immune cell activation, migration, and effector functions

  • Involvement in antigen presentation or immune synapse formation

• Inflammatory pathway interaction:

  • Relationship between TSPAN7 and inflammatory signaling pathways

  • Cross-talk with cytokine receptors and inflammatory mediators

  • Effects on transcriptional regulation of inflammatory responses

• Neuroinflammation:

  • Given TSPAN7's brain expression and neurological associations , its role in neuroinflammatory processes

  • Potential involvement in microglial or astrocyte responses

  • Implications for neurodegenerative disease mechanisms

How might TSPAN7-targeted approaches advance therapeutic development?

TSPAN7's roles in neurological disorders and cancer suggest therapeutic potential:

• Neurological applications:

  • Gene therapy approaches for X-linked mental retardation

  • Small molecule modulators enhancing TSPAN7 function

  • Targeting TSPAN7-integrin interactions to influence neuronal development

• Oncological approaches:

  • TSPAN7 restoration strategies for gliomas

  • Development as a prognostic biomarker for treatment stratification

  • Targeting downstream pathways affected by TSPAN7 loss

• Technical challenges:

  • Blood-brain barrier penetration for CNS-targeted therapies

  • Cell-type specific delivery strategies

  • Maintaining functional protein conformation in therapeutic formulations

• Combination approaches:

  • Integration with existing treatment modalities

  • Potential synergy with immunotherapies given emerging immune functions

  • Multi-targeted approaches addressing TSPAN7-related pathways

What knowledge gaps exist in cross-species TSPAN7 research?

Critical areas for further investigation include:

• Comparative genomics and proteomics:

  • Systematic comparison of TSPAN7 across primates and mammals

  • Identification of conserved functional domains versus species-specific adaptations

  • Examination of regulatory mechanisms controlling expression

• Functional conservation assessment:

  • Whether TSPAN7's roles in neurite outgrowth and signaling are conserved across species

  • Comparative analysis of binding partners and interaction networks

  • Species-specific post-translational modifications and their functional implications

• Pan troglodytes TSPAN7 characterization:

  • Comprehensive tissue expression profiling

  • Direct biochemical and functional comparison with human TSPAN7

  • Identification of any functional differences informing human-specific traits

• Evolutionary perspectives:

  • Analysis of selective pressures on TSPAN7 throughout primate evolution

  • Correlation with emergence of advanced cognitive functions

  • Implications for understanding human-specific neurological disorders

• Model system relevance:

  • Evaluation of how faithfully various model organisms recapitulate human TSPAN7 function

  • Development of appropriate models for studying TSPAN7-related disorders

  • Consideration of species-specific differences when interpreting experimental results