Recombinant Mouse Tumor necrosis factor receptor superfamily member 11A (Tnfrsf11a)

What is TNFRSF11A and what is its primary function in physiological systems?

TNFRSF11A (Tumor Necrosis Factor Receptor Superfamily Member 11A), also known as RANK (Receptor Activator of Nuclear Factor κB), is a protein that plays a crucial role in bone remodeling. It helps direct the formation and function of specialized cells called osteoclasts, which are responsible for breaking down bone tissue during the normal bone renewal process. TNFRSF11A is located on the surface of immature osteoclasts, where it receives signals that trigger these cells to mature and become fully functional .

Beyond bone remodeling, TNFRSF11A is an important regulator of the interaction between T cells and dendritic cells and serves as an essential mediator for lymph node development. At the molecular level, this receptor can interact with various TRAF family proteins, through which it induces the activation of NF-kappa B and MAPK8/JNK signaling pathways .

What is the molecular structure of mouse TNFRSF11A protein?

Mouse TNFRSF11A is a type I transmembrane protein consisting of 625 amino acids with distinct structural domains:

• A 184 amino acid extracellular domain containing two potential N-linked glycosylation sites and four cysteine-rich repeats characteristic of the TNF receptor family

• A transmembrane region

• A 391 amino acid cytoplasmic domain

The extracellular domain (specifically from Gln30 to Pro213) is often used in recombinant protein constructs for research purposes. The extracellular domain of mouse TNFRSF11A shares approximately 81% amino acid identity with its human counterpart, making mouse models valuable for studying human-relevant pathways .

What genetic disorders are associated with mutations in TNFRSF11A?

Several bone disorders have been linked to mutations in the TNFRSF11A gene:

• Osteopetrosis (specifically autosomal recessive osteopetrosis 7) - characterized by abnormally dense bones that are prone to fracture

• Paget disease of bone (early-onset form) - resulting from duplication mutations that lead to overactivation of the signaling pathway promoting osteoclast formation

• Familial expansile osteolysis (FEO) - a rare bone disorder with similarities to Paget disease

• Expansile skeletal hyperphosphatasia (ESH) - another rare bone condition with features similar to FEO

These disorders generally involve dysregulation of bone remodeling processes, leading to abnormal bone structure and function.

What are the recommended methods for reconstitution and storage of recombinant mouse TNFRSF11A protein?

For optimal handling of recombinant mouse TNFRSF11A protein:

Reconstitution protocol:

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

• Reconstitute the 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% (with 50% being the standard recommendation)

• Aliquot for long-term storage to avoid repeated freeze-thaw cycles

Storage conditions:

• Store lyophilized protein at -20°C/-80°C upon receipt

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

• For long-term storage of reconstituted protein, maintain at -20°C/-80°C with glycerol added

• Avoid repeated freeze-thaw cycles as this can degrade protein activity

How can I verify the purity and activity of recombinant mouse TNFRSF11A protein?

Purity verification:

• SDS-PAGE analysis is recommended for assessing protein purity, with high-quality preparations typically showing >90% purity

• Western blot using anti-TNFRSF11A or anti-tag (such as His-tag) antibodies can confirm identity

Activity assessment:

• Functional assays typically measure the protein's ability to inhibit RANKL-induced osteoclastogenesis

• The effective concentration (EC50) for this inhibition is approximately 0.05-0.15 μg/mL when tested in the presence of 10 ng/mL of recombinant mouse TRANCE (RANKL)

• Binding assays using surface plasmon resonance or ELISA can be used to verify interaction with RANKL

What expression systems are commonly used for producing recombinant mouse TNFRSF11A protein?

Several expression systems can be used to produce recombinant mouse TNFRSF11A:

For research applications requiring structural studies or basic binding assays, E. coli-expressed protein (as seen in search result ) may be sufficient. For applications where proper glycosylation is critical to function, mammalian expression systems are preferred .

How can recombinant TNFRSF11A be used to study bone remodeling disorders in mouse models?

Recombinant mouse TNFRSF11A can be utilized in several experimental approaches to study bone remodeling disorders:

In vitro applications:

• Osteoclast differentiation assays: Recombinant TNFRSF11A-Fc chimeric proteins can inhibit RANKL-induced osteoclastogenesis in bone marrow-derived macrophage cultures

• Signal transduction studies: To investigate the activation of NF-κB and MAPK pathways downstream of RANK signaling

• Binding interaction studies: To screen for novel molecules that can modulate RANK-RANKL interactions

In vivo applications:

• Administration of recombinant TNFRSF11A-Fc fusion proteins can be used to block endogenous RANKL activity in mouse models of bone disorders

• Genetic rescue experiments in TNFRSF11A knockout mice can help define gene function and disease mechanisms

• Comparative studies using wild-type versus mutant forms of recombinant TNFRSF11A (containing disease-associated mutations) can reveal pathological mechanisms

These approaches can provide insights into conditions such as osteopetrosis, Paget's disease of bone, and other TNFRSF11A-associated disorders.

What is the role of TNFRSF11A in cardiovascular research, and how can recombinant proteins aid these studies?

Recent research has revealed an unexpected role for the RANKL/RANK/OPG system in vascular calcification and blood pressure regulation:

Cardiovascular implications:

• Genetic variation in TNFRSF11A has been associated with hypertension and blood pressure regulation in clinical studies

• Specifically, SNPs rs6567270, rs4603673, and rs9646629 in TNFRSF11A have shown significant associations with hypertension and/or blood pressure measurements in postmenopausal Chinese women

Research applications of recombinant TNFRSF11A:

• In vitro vascular smooth muscle cell calcification models to study the mechanistic role of RANK signaling

• Ex vivo vessel ring studies to assess the direct effects of RANK activation on vascular tone

• In vivo administration to evaluate effects on blood pressure in hypertensive mouse models

• As a tool to block RANKL-RANK interactions in models of vascular calcification

These applications could lead to novel therapeutic approaches for cardiovascular conditions beyond the traditional focus on bone disorders.

How can researchers design experiments to investigate the cross-talk between TNFRSF11A signaling and other inflammatory pathways?

TNFRSF11A is part of the larger TNF receptor superfamily and interacts with multiple signaling pathways. To investigate these interactions:

Experimental approaches:

• Co-immunoprecipitation studies using recombinant TNFRSF11A to identify novel binding partners

• Phosphoproteomic analysis following RANKL stimulation to map signaling networks

• CRISPR/Cas9-mediated gene editing of pathway components combined with recombinant TNFRSF11A stimulation

• RNA-seq analysis of cells treated with recombinant TNFRSF11A under various inflammatory conditions

Key pathway interactions to investigate:

• NF-κB pathway activation kinetics and feedback mechanisms

• MAPK signaling cascade specificity and duration

• Cross-regulation between RANK and other TNF family receptors

• Influence of inflammatory cytokines (IL-1, TNF-α, IL-6) on RANK signaling efficiency

These studies could reveal new therapeutic targets for both bone and inflammatory disorders where TNFRSF11A plays a significant role.

What are common challenges when working with recombinant TNFRSF11A proteins and how can they be addressed?

Researchers frequently encounter several technical issues when working with recombinant TNFRSF11A:

Additionally, when using Fc-fusion TNFRSF11A proteins, researchers should be aware of potential Fc-mediated effects and include appropriate Fc-only controls in experimental designs .

How can researchers accurately quantify TNFRSF11A expression and activation in experimental models?

Accurate quantification of TNFRSF11A expression and activation is essential for interpreting experimental results:

Expression quantification methods:

• qRT-PCR for mRNA expression analysis

• Western blotting for protein expression (using validated antibodies)

• Flow cytometry for cell surface expression levels

• Immunohistochemistry for tissue localization studies

Activation assessment:

• Phospho-specific antibodies to detect activation-associated phosphorylation events

• Nuclear translocation of NF-κB using immunofluorescence or cell fractionation

• Downstream gene expression analysis of RANK-responsive genes (e.g., NFATc1, c-Fos)

• TRAF adaptor protein recruitment using co-immunoprecipitation assays

When comparing results across different models or experimental conditions, consistent methodology and appropriate normalization controls are critical for reliable data interpretation .

What are emerging areas of research involving TNFRSF11A beyond bone biology?

While TNFRSF11A's role in bone biology is well-established, several emerging research areas show promise:

• Cardiovascular biology: Further exploration of TNFRSF11A's role in hypertension and vascular calcification could reveal new therapeutic targets for cardiovascular diseases

• Immunology: As TNFRSF11A regulates interactions between T cells and dendritic cells, its role in autoimmune diseases and cancer immunotherapy warrants investigation

• Neuroscience: Preliminary evidence suggests RANK signaling may influence brain development and function, opening new avenues for neurological research

• Metabolism: Connections between bone remodeling and energy metabolism suggest TNFRSF11A may have unexplored roles in metabolic disorders

• Development: As an essential mediator for lymph node development, TNFRSF11A's broader developmental roles remain to be fully characterized

Recombinant TNFRSF11A proteins will be valuable tools in exploring these emerging research areas.

How might genome editing technologies advance our understanding of TNFRSF11A function?

CRISPR/Cas9 and other genome editing technologies offer powerful approaches to study TNFRSF11A:

Research applications:

• Generation of knock-in mouse models carrying specific disease-associated mutations (such as those causing Paget's disease or osteopetrosis)

• Domain-specific modifications to determine functional importance of different protein regions

• Regulatory element editing to understand transcriptional control mechanisms

• Cell-specific conditional knockout systems to dissect tissue-specific roles

• Humanized mouse models expressing human TNFRSF11A to improve translational relevance

Methodological considerations:

• Careful design of guide RNAs to minimize off-target effects

• Validation of edits at both genomic and protein levels

• Phenotypic characterization across multiple systems (bone, immune, vascular)

• Comparison with recombinant protein studies to correlate structure with function

These approaches could reveal new aspects of TNFRSF11A biology and identify novel therapeutic targets for related disorders.