Recombinant Human IFT81 Protein: Properties & Research Guide

Recombinant Human IFT81 Protein is a key research reagent enabling scientists to investigate intraflagellar transport complex B assembly, ciliogenesis mechanisms, and ciliopathy-related pathways in vitro and in biochemical assays.

Product Name

Recombinant Human IFT81 Protein

SKU

rp375136

Protein Family

IFT-B complex subunit (Intraflagellar Transport Complex B)

Primary Research Applications

Ciliogenesis studies, IFT complex assembly assays, ciliopathy research, protein interaction studies

Species Origin

Human (Homo sapiens)

Supplier

Aladdin Scientific

Storage Recommendation

Avoid repeated freeze-thaw cycles; store aliquots at -80°C for long-term stability (verify with datasheet)

Introduction to IFT81 and Its Biological Role

IFT81 (Intraflagellar Transport Protein 81) is an essential component of the IFT-B complex, a multi-subunit assembly that mediates the anterograde transport of cargo along ciliary and flagellar axonemes. Cilia are microtubule-based organelles present on the surface of most mammalian cell types, where they perform critical sensory, motility, and signaling functions.

IFT81 forms a core module within the IFT-B complex together with IFT74, and this heterodimer plays a direct role in tubulin transport into the cilium. The N-terminal calponin-homology (CH) domain of IFT81 binds to tubulin, making it indispensable for ciliary assembly. Disruption of IFT81 function is associated with a range of human ciliopathies, including disorders affecting kidney, retina, and skeletal development.

Recombinant Human IFT81 Protein (rp375136) from Aladdin Scientific provides researchers with a well-defined, ready-to-use tool for dissecting these molecular mechanisms in vitro.

Protein Specifications and Quality Considerations

When selecting a recombinant protein for experimental use, understanding its production system, purity, and formulation is critical for reproducible results. The following general specifications apply to recombinant proteins of this class; researchers should consult the official Aladdin Scientific product datasheet for rp375136 to confirm lot-specific parameters.

• Expression System: Recombinant IFT81 is typically produced in a heterologous expression system (e.g., E. coli, insect cells, or mammalian cells). The specific host system affects post-translational modifications and folding—refer to the product datasheet for confirmed expression system details.
• Tag Information: Many recombinant IFT81 preparations carry an affinity tag (e.g., His-tag or GST-tag) to facilitate purification. Tag position (N- or C-terminal) may influence functional assays and should be verified before experimental design.
• Purity: High-purity preparations (typically ≥85–95% by SDS-PAGE) are recommended for binding and functional studies. Verify purity grade with the certificate of analysis (CoA).
• Formulation and Storage Buffer: Proteins are generally supplied in a buffered solution with stabilizing additives. Long-term storage at -80°C in single-use aliquots is recommended to prevent activity loss from freeze-thaw cycling.

Note: Specific numerical values for molecular weight, concentration, and purity must be confirmed from the product datasheet and CoA provided with each lot.

Recommended Handling and Storage Protocol

Proper handling of recombinant proteins is essential to preserve their structural integrity and biological activity. Follow the guidelines below when working with Recombinant Human IFT81 Protein (rp375136):

1. Upon Receipt: Inspect packaging integrity. If the product arrives on dry ice, briefly centrifuge the vial before opening to consolidate contents. Record the lot number and expiry date.
2. Aliquoting: To minimize freeze-thaw degradation, prepare single-use aliquots on ice immediately upon first thaw. Avoid working with the entire stock vial for a single experiment.
3. Short-Term Storage: For use within 1–2 weeks, store at 4°C. Avoid exposure to repeated temperature fluctuations.
4. Long-Term Storage: Store aliquots at -80°C. Addition of a carrier protein such as 0.1% BSA may improve long-term stability in some formulations—consult the datasheet.
5. Working Concentrations: Determine optimal working concentrations empirically for each assay type (e.g., ELISA, pull-down, SPR). Start with the manufacturer's recommended range if provided.
6. Avoid: Repeated freeze-thaw cycles, prolonged exposure to room temperature, and vortexing. Gently mix by pipetting or brief centrifugation.

Always refer to the current product datasheet and safety data sheet (SDS) supplied with your specific lot for authoritative handling instructions.

Research Applications of Recombinant Human IFT81 Protein

Recombinant Human IFT81 Protein supports a broad range of experimental applications in cilia biology and related fields. Key applications include:

• Protein–Protein Interaction Studies: IFT81 interacts with multiple IFT-B subunits, most notably IFT74. Co-immunoprecipitation (co-IP), GST pull-down, and surface plasmon resonance (SPR) assays can be used to map these interactions and assess binding kinetics using recombinant IFT81 as bait or analyte.
• Tubulin-Binding Assays: The calponin-homology domain of IFT81 directly binds free tubulin. Recombinant IFT81 protein can be employed in tubulin co-sedimentation assays or isothermal titration calorimetry (ITC) to characterize this interaction.
• Structural Biology: Recombinant IFT81 is suitable as a component for cryo-electron microscopy (cryo-EM) or X-ray crystallography studies aimed at resolving IFT-B complex architecture.
• Antibody Validation: Recombinant IFT81 serves as a positive control antigen for validating anti-IFT81 antibodies in Western blotting, ELISA, and immunofluorescence applications.
• Ciliopathy Mechanism Research: Functional reconstitution experiments using recombinant IFT81 can help elucidate molecular defects underlying ciliopathies caused by IFT81 mutations.
• Drug Discovery and Screening: As a defined molecular target, recombinant IFT81 can be incorporated into binding assays for compound screening programs targeting cilia-related diseases.

Troubleshooting Common Experimental Issues

Researchers may encounter the following challenges when using Recombinant Human IFT81 Protein. The guidance below represents general best-practice recommendations:

Issue	Possible Cause	Recommended Action
Low or no signal in pull-down assay	Protein aggregation or denaturation due to improper storage or handling	Ensure protein was stored correctly; use freshly thawed aliquots; verify protein integrity by SDS-PAGE before use
Non-specific bands on Western blot	Contaminating proteins or non-specific antibody binding	Increase wash stringency; use recombinant IFT81 as a positive control to confirm antibody specificity
Poor reproducibility between experiments	Freeze-thaw degradation or pipetting variability with concentrated stocks	Prepare consistent aliquots; dilute to working concentrations in a compatible buffer; include internal controls
Precipitation of protein in assay buffer	Buffer incompatibility or protein concentration too high	Optimize buffer composition (pH, salt, detergent); dilute protein; centrifuge at 10,000×g for 10 min before use to remove aggregates

For issues not resolved by the above measures, contact Aladdin Scientific technical support with your lot number and experimental details.

Frequently asked questions

What is the biological function of IFT81 in human cells?

IFT81 is a core subunit of the IFT-B complex required for anterograde intraflagellar transport—the movement of protein cargo from the ciliary base toward the ciliary tip. Its calponin-homology domain binds free tubulin and is essential for delivering tubulin dimers into growing cilia. Loss-of-function mutations in IFT81 are associated with human ciliopathies including skeletal dysplasias and retinal dystrophies.

How should Recombinant Human IFT81 Protein (rp375136) be stored to maintain activity?

For long-term storage, aliquot the protein upon first thaw and store at -80°C to avoid repeated freeze-thaw cycles that degrade activity. For short-term use within one to two weeks, storage at 4°C is acceptable. Always consult the product datasheet and certificate of analysis supplied with your lot for formulation-specific storage recommendations.

Which assay types are suitable for Recombinant Human IFT81 Protein?

Recombinant Human IFT81 Protein is suitable for protein–protein interaction assays (co-IP, pull-down, SPR), tubulin-binding assays (co-sedimentation, ITC), antibody validation (Western blot, ELISA), and structural studies (cryo-EM, crystallography). It may also be used in drug discovery binding screens. Optimal conditions should be determined empirically for each specific assay.

Can Recombinant Human IFT81 Protein be used as a positive control in Western blotting?

Yes. Recombinant Human IFT81 Protein is an ideal positive control antigen for validating anti-IFT81 antibodies in Western blotting. Load a defined quantity alongside your cell or tissue lysate samples to confirm antibody specificity and expected molecular weight migration. Verify the expected apparent molecular weight from the product datasheet.

What should I do if the protein precipitates in my assay buffer?

Precipitation typically results from buffer incompatibility or excessive protein concentration. To resolve this, optimize buffer pH, salt concentration, and detergent content; dilute the protein to a lower working concentration; and centrifuge the protein solution at approximately 10,000×g for 10 minutes before use to pellet aggregates. Contact Aladdin Scientific technical support if the problem persists.

References

1. Bhogaraju S, Cajanek L, Fort C, Blisnick T, Weber K, Taschner M, Mizuno N, Lamla S, Bastin P, Nigg EA, Lorentzen E. Molecular basis of tubulin transport within the cilium by IFT74 and IFT81. Science. 2013;341(6149):1009-1012. doi:10.1126/science.1240985
2. Taschner M, Weber K, Mourao A, Vetter M, Awasthi M, Stiegler M, Bhogaraju S, Lorentzen E. Intraflagellar transport proteins 172, 80, 57, 54, 38, and 20 form a stable tubulin-binding IFT-B2 complex. EMBO J. 2016;35(7):773-790. doi:10.15252/embj.201593164
3. Perrault I, Halbritter J, Porath JD, et al. IFT81, encoding an IFT-B core protein, as a very rare cause of a ciliopathy phenotype. J Med Genet. 2015;52(10):657-665. doi:10.1136/jmedgenet-2015-103319

Products are supplied for research and development use only. Not for use in humans, animals, diagnosis, or therapy.