Recombinant Rabbit Growth hormone receptor (GHR)
Description
Production and Physicochemical Properties
Mechanism of Activation
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GH binding induces conformational changes, enabling GHR dimerization and JAK2 kinase activation .
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The TMD influences receptor conformation but is not essential for dimerization .
Proteolytic Cleavage and GHBP Shedding
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Cleavage occurs 8–10 residues from the transmembrane domain in rabbits .
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Mutagenesis studies show that replacing rabbit cleavage sites with mouse sequences reduces proteolysis by 40–60% .
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Inhibitors like benzamidine and temperature shifts modulate GHBP release .
Key Research Findings
Applications in Research
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GH Signaling Studies: Used to map JAK2/STAT5 activation and ERK pathways .
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Disease Modeling: Facilitates research on Laron syndrome (GH insensitivity) .
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Drug Development: Serves as a target for monoclonal antibodies and metalloprotease inhibitors .
Microarray and Proteomic Insights
Product Specs
Note: We prioritize shipping the format currently in stock. However, if you have specific format requirements, please indicate them in your order remarks. We will fulfill your request as best as possible.
Note: All our proteins are shipped with standard blue ice packs by default. If you require dry ice shipping, please communicate this to us in advance, as additional charges will apply.
Generally, liquid forms have a shelf life of 6 months at -20°C/-80°C. Lyophilized forms have a shelf life of 12 months at -20°C/-80°C.
Target Background
- Fos-zippered GHR tails and Jak2, both purified from baculovirus-infected insect cells, interacted via box1 with a binding affinity of approximately 40nM. PMID: 26859362
- Jak2 binding to the growth hormone receptor prevents endocytosis in a non-catalytic manner PMID: 21347402
- GHR gene may be a candidate gene responsible for butcher trait in rabbit. PMID: 19073551
Q&A
What expression systems are suitable for producing recombinant rabbit GHR?
Recombinant rabbit GHR has been successfully expressed in Escherichia coli expression systems to produce protein fragments with biological activity . For researchers requiring mammalian post-translational modifications, CHO cell expression systems have proven effective for similar recombinant proteins, though they generally yield lower production levels compared to prokaryotic systems . When selecting an expression system, consider the following methodology:
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For structural studies requiring high protein yields: Prokaryotic systems (E. coli) are preferable
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For functional studies requiring proper folding and glycosylation: Mammalian systems (CHO cells) are more appropriate
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For protein fragment studies: E. coli systems using the specific sequence "AFSGS" have been validated
How can researchers verify the identity and purity of recombinant rabbit GHR?
Verification of recombinant rabbit GHR identity and purity requires multiple complementary techniques:
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Western blotting: Confirm identity using specific antibodies like the Rabbit Monoclonal Antibody [JU01-34] that reacts with growth hormone receptor
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Mass spectrometry: Perform fingerprint analysis combined with MALDI-TOF as utilized for similar recombinant rabbit proteins
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N-terminal sequencing: Verify the correct amino acid sequence, particularly focusing on the starting sequence "AFSGS" for protein fragments
What applications are appropriate for recombinant rabbit GHR in research settings?
Recombinant rabbit GHR has demonstrated utility in several research applications:
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Binding studies: To investigate ligand-receptor interactions with rabbit growth hormone
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Cross-reactivity analysis: The receptor has shown cross-reactivity with human, mouse, and rat samples, facilitating comparative studies
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SDS-PAGE applications: For protein characterization and quantification
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Functional assays: Similar to the LHRE-TK-Luciferase reporter gene system used for assessing recombinant human growth hormone bioactivity
How can the Taguchi experimental design be adapted for optimizing rabbit GHR production?
The Taguchi experimental design provides a systematic approach to optimize recombinant rabbit GHR production while minimizing experimental variables:
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Establish an orthogonal array (e.g., M16) to systematically evaluate multiple culture components
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Test critical variables affecting GHR expression:
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DMSO concentration (optimal range: 0-1%)
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Glycerol concentration (optimal range: 0-1%)
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Zinc supplementation (e.g., ZnSO₄ at 25 μM)
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Sodium butyrate concentration (0-10 mM)
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Based on similar optimization studies with recombinant human growth hormone, conditions of 1% DMSO, 1% glycerol, 25 μM ZnSO₄ and 0 mM sodium butyrate have shown maximal productivity in mammalian expression systems . This methodological approach reduces experimental errors and enhances reproducibility for rabbit GHR production.
What strategies can be employed to enhance the biological activity of recombinant rabbit GHR?
Enhancing biological activity of recombinant rabbit GHR requires attention to proper protein folding and preservation of binding domains:
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Expression system selection: While E. coli provides high yields , mammalian cells like CHO can provide improved post-translational modifications crucial for receptor functionality
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Purification method optimization: Affinity chromatography preserves structural integrity as demonstrated with similar rabbit recombinant proteins
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Buffer composition: Including stabilizing agents such as glycerol (1%) can maintain protein conformation
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Metal ion supplementation: Addition of zinc (ZnSO₄ at 25 μM) has shown benefits for similar recombinant proteins
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Amino acid sequence verification: Ensure critical binding domains are preserved, particularly at receptor binding sites which show species-specific variations
How can researchers quantitatively assess the binding affinity of recombinant rabbit GHR?
Quantitative assessment of binding affinity requires specialized methodologies:
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Surface Plasmon Resonance (SPR): Measure real-time binding kinetics between rabbit GHR and growth hormone
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Isothermal Titration Calorimetry (ITC): Determine thermodynamic parameters of binding
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Reporter gene assays: Adapt the LHRE-TK-Luciferase system used for human growth hormone bioactivity assessment
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Competitive binding assays: Using labeled growth hormone and varying concentrations of rabbit GHR
Researchers should establish standardized conditions and compare binding affinities with GHR from other species to accurately interpret results.
What are the key structural differences between rabbit GHR and GHRs from other species?
The structural analysis of rabbit GHR compared to other species reveals several important differences:
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Receptor binding sites: In comparing rabbit NGF (as a model for receptor-ligand interactions) with other species, significant differences were observed in the N-terminal binding regions and receptor recognition sites
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Amino acid substitutions: Specific substitutions in the amino acid sequence may condition the physiological actions of the receptor
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Binding domain configuration: Rabbits show unique configurations in key binding domains that may affect interaction with growth hormone
These structural differences highlight the importance of species-specific recombinant proteins for accurate research, rather than assuming cross-species functionality.
How does post-translational modification affect rabbit GHR functionality?
Post-translational modifications significantly impact rabbit GHR functionality:
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Glycosylation patterns: While E. coli-expressed rabbit GHR lacks glycosylation , mammalian cell expression systems can provide proper glycosylation that may be critical for some receptor functions
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Disulfide bond formation: Proper disulfide bonds are essential for maintaining the three-dimensional structure necessary for hormone binding
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Phosphorylation sites: Phosphorylation status affects signaling cascade activation
Researchers studying specific GHR functions should select expression systems that provide the appropriate post-translational modifications for their research questions.
How do bioassay results of rabbit GHR compare with GHR from other species?
Comparative bioassays between rabbit GHR and other species provide important insights into functional conservation and divergence:
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Cross-reactivity potential: Rabbit monoclonal antibodies to growth hormone receptor show reactivity with human, mouse, and rat samples , suggesting conserved epitopes
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Signaling pathway activation: Similar to human growth hormone studies, rabbit GHR likely induces GH-mediated intracellular signaling cascades
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Species-specific variations: While some biological functions may be conserved across species, specific amino acid differences in binding domains could modify receptor-hormone interactions
When designing comparative studies, researchers should use standardized methodologies to accurately assess functional similarities and differences.
What methodological considerations are important when comparing rabbit GHR with human GHR?
When comparing rabbit and human GHR, researchers should consider these methodological approaches:
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Sequence alignment analysis: Perform detailed alignment of binding domains and signaling regions
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Binding affinity studies: Use identical experimental conditions and ligand concentrations
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Reporter gene systems: Implement the LHRE-TK-Luciferase reporter gene system for standardized bioactivity comparison
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Cross-reactivity testing: Assess interaction of rabbit GHR with human growth hormone and vice versa
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Structural modeling: Create comparative models of binding domains to predict interaction differences
What are common challenges in purifying recombinant rabbit GHR and their solutions?
Purification of recombinant rabbit GHR presents several challenges that can be addressed with specific strategies:
How can researchers validate the functional integrity of purified recombinant rabbit GHR?
Validation of functional integrity requires multiple complementary approaches:
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Ligand binding assays: Confirm ability to bind rabbit growth hormone
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Cell-based signaling assays: Similar to PC12 cell differentiation assays used for rabbit β-NGF
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Western blotting with conformation-specific antibodies: Use antibodies that recognize the properly folded receptor
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Circular dichroism (CD) spectroscopy: Assess secondary structure content
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Thermal stability analysis: Determine if the protein maintains stability at physiological temperatures
