SEMA7A Human
Description
SEMA7A produced in Sf9 Insect cells is a single, glycosylated polypeptide chain containing 846 amino acids (45-648 a.a.) and having a molecular mass of 95.7kDa (Molecular size on SDS-PAGE will appear at approximately 70-100kDa).
SEMA7A is expressed with an 242 amino acid hIgG-His tag at C-Terminus and purified by proprietary chromatographic techniques.
Product Specs
SEMA7A (semaphorin-7A isoform 1) is a membrane-bound protein that belongs to the semaphorin family. It is attached to the cell surface through a glycosylphosphatidylinositol (GPI) anchor. SEMA7A plays a crucial role in cell signaling by promoting the formation of focal adhesion complexes and activating the protein kinase PTK2/FAK1, which in turn leads to the phosphorylation of MAPK3 and MAPK1. This signaling pathway is important for cell migration and immune responses. SEMA7A is involved in integrin-mediated signaling and regulates cell movement. Furthermore, it stimulates macrophages and monocytes to produce pro-inflammatory cytokines, contributing to the inflammatory process.
Recombinant SEMA7A protein, produced in Sf9 insect cells, is a single polypeptide chain with glycosylation. It consists of 846 amino acids (residues 45-648) and has a molecular weight of 95.7 kDa. However, on SDS-PAGE, it appears as a band between 70-100 kDa due to glycosylation. The protein includes a 242 amino acid hIgG-His tag at the C-terminus and is purified using proprietary chromatographic techniques.
The product is a sterile, colorless solution.
The SEMA7A protein solution is provided at a concentration of 0.25 mg/ml in Phosphate Buffered Saline (pH 7.4) containing 10% glycerol.
For short-term storage (up to 2-4 weeks), the product can be stored at 4°C. For long-term storage, it is recommended to store the protein at -20°C. To further enhance stability during long-term storage, adding a carrier protein such as HSA or BSA (0.1%) is advised. Repeated freezing and thawing of the product should be avoided.
The purity of the SEMA7A protein is greater than 90%, as determined by SDS-PAGE analysis.
Semaphorin-7A, CDw108, JMH blood group antigen, John-Milton-Hargen human blood group Ag, Semaphorin-K1, Sema K1, Semaphorin-L, Sema L, CD108.
Sf9, Insect cells.
ADPQGHLRSG PRIFAVWKGH VGQDRVDFGQ TEPHTVLFHE PGSSSVWVGG RGKVYLFDFP EGKNASVRTV NIGSTKGSCL DKRDCENYIT LLERRSEGLL ACGTNARHPS CWNLVNGTVV PLGEMRGYAP FSPDENSLVL FEGDEVYSTI RKQEYNGKIP RFRRIRGESE LYTSDTVMQN PQFIKATIVH QDQAYDDKIY YFFREDNPDK NPEAPLNVSR VAQLCRGDQG GESSLSVSKW NTFLKAMLVC SDAATNKNFN RLQDVFLLPD PSGQWRDTRV YGVFSNPWNY SAVCVYSLGD IDKVFRTSSL KGYHSSLPNP RPGKCLPDQQ PIPTETFQVA DRHPEVAQRV EPMGPLKTPL FHSKYHYQKV AVHRMQASHG ETFHVLYLTT DRGTIHKVVE PGEQEHSFAF NIMEIQPFRR AAAIQTMSLD AERRKLYVSS QWEVSQVPLD LCEVYGGGCH GCLMSRDPYC GWDQGRCISI YSSERSVLQS INPAEPHKEC PNPKPDKAPL QKVSLAPNSR YYLSCPMESR HATYSWRHKE NVEQSCEPGH QSPNCILFIE NLTAQQYGHY FCEAQEGSYF REAQHWQLLP EDGIMAEHLL GHACALALEP KSCDKTHTCP PCPAPELLGG PSVFLFPPKP KDTLMISRTP EVTCVVVDVS HEDPEVKFNW YVDGVEVHNA KTKPREEQYN STYRVVSVLT VLHQDWLNGK EYKCKVSNKA LPAPIEKTIS KAKGQPREPQ VYTLPPSRDE LTKNQVSLTC LVKGFYPSDI AVEWESNGQP ENNYKTTPPV LDSDGSFFLY SKLTVDKSRW QQGNVFSCSV MHEALHNHYT QKSLSLSPGK HHHHHH.
Q&A
Basic Research Questions
What experimental approaches are used to characterize SEMA7A's structural and genetic features?
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Methodology:
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Genetic analysis: Use NCBI Gene ID 8482 for genomic locus identification, splice variants, and promoter regions .
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Protein structure: Employ mass spectrometry to confirm GPI anchoring and glycosylation status .
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Functional domains: Perform truncation mutagenesis to identify domains critical for receptor binding (e.g., β1 integrin or plexin C1) .
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How is SEMA7A’s tissue-specific expression validated in human studies?
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Methodology:
What assays determine SEMA7A’s role in immune cell regulation?
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Methodology:
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Macrophage polarization: Stimulate human PBMCs with GM-CSF/M-CSF ± SEMA7A, then assess M1/M2 markers (CD40, CD206) via RNA-seq and flow cytometry .
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Chemotaxis assays: Use transwell systems to measure macrophage migration toward SEMA7A gradients .
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Cytokine profiling: ELISA for IL-10, TNF-α, and TGF-β2 in conditioned media .
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Advanced Research Questions
How to investigate SEMA7A’s role in macrophage metabolic reprogramming?
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Methodology:
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Metabolomic profiling: Compare WT vs. Sema7A−/− macrophages using LC-MS to quantify TCA cycle intermediates (e.g., succinate, citrate) .
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Pathway inhibition: Block mTOR/AKT2 with rapamycin or MK-2206 to validate their role in SEMA7A-induced oxidative phosphorylation .
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SPM synthesis: Measure prostaglandins (PGD₂, PGE₂) and resolvins via lipidomics during inflammation resolution .
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| Key Finding | Experimental Model | Source |
|---|---|---|
| SEMA7A ↑ citrate → ↑ proresolving mediators | Murine peritonitis | |
| Glycolysis ↑ in Sema7A−/− MΦs | Human PBMCs |
How to resolve contradictory data on SEMA7A’s pro- vs. anti-inflammatory roles?
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Methodology:
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Context-dependent models: Compare sepsis (proinflammatory) vs. colitis (anti-inflammatory) .
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Receptor specificity: Use β1 integrin KO mice to dissect signaling pathways in endothelial vs. immune cells .
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Time-course experiments: Measure SEMA7A levels at inflammation onset (4 h) vs. resolution (12–24 h) .
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What models are used to study SEMA7A-driven endothelial-to-mesenchymal transition (EndMT)?
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Methodology:
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In vitro: Transfect HUVECs with SEMA7A plasmids and quantify EndMT markers (α-SMA, CD31) via Western blot .
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In vivo: Use partial carotid ligation (PCL) in SEMA7A-KO mice and assess co-localization of CD31/α-SMA by immunofluorescence .
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Mechanistic studies: siRNA knockdown of ATF3/TGF-β2 to block SEMA7A-induced EndMT .
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How to validate SEMA7A as a clinical biomarker for inflammatory diseases?
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Methodology:
| Study Cohort | SEMA7A Level (ng/mL) | Correlation with Disease Severity |
|---|---|---|
| AAS patients (n=120) | 12.3 ± 3.1 | OR = 2.4 (95% CI: 1.6–3.8) |
| Sepsis survivors (n=45) | 8.9 ± 2.7 | Survival ↑ 200% with SEMA7A therapy |
What strategies identify SEMA7A’s signaling partners in vivo?
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Methodology:
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Co-IP/mass spectrometry: Immunoprecipitate SEMA7A from macrophage lysates to detect β1 integrin or plexin C1 interactions .
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Phosphoproteomics: Map AKT2/mTOR activation in SEMA7A-stimulated cells using phospho-specific antibodies .
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CRISPR screening: Perform genome-wide KO screens to identify genes modulating SEMA7A’s proresolving effects .
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Product Science Overview
Sema7A is an approximately 80 kDa membrane-anchored glycoprotein that associates with cell surfaces via a glycosylphosphatidylinositol (GPI) linkage . It is expressed in various adult tissues, including the spleen, colon, esophagus, heart, brain, spleen, testis, lung, ovary, and uterus . On human erythrocytes, it is recognized as the JMH blood group antigen .
Sema7A plays a crucial role in both the nervous and immune systems. In the nervous system, it is involved in axon guidance, cell differentiation, and neuron projection development . In the immune system, Sema7A acts as a potent immunomodulator, influencing the behavior of lymphoid and myeloid cells . It has been shown to modulate cellular immune responses, particularly in the context of autoimmune diseases like rheumatoid arthritis (RA) .
Research has highlighted the therapeutic potential of Sema7A in treating autoimmune diseases. For instance, elevated levels of soluble Sema7A (sSema7A) have been observed in the serum and synovial fluid of patients with RA, correlating with disease activity markers . Sema7A has been found to significantly increase the secretion of proinflammatory cytokines and activate T cells and monocytes . Blocking Sema7A with specific antibodies has shown promise in reducing inflammation and disease progression in experimental models of RA .
