Recombinant Human IFT74 Protein: Function & Research Use

Recombinant Human IFT74 Protein is a critical subunit of the intraflagellar transport complex B, essential for the bidirectional movement of cargo along ciliary axonemes and the proper assembly and maintenance of cilia across virtually all vertebrate cell types.

Protein Name

Recombinant Human IFT74 (Intraflagellar Transport Protein 74)

Complex Association

IFT Complex B subunit

Primary Biological Function

Facilitates anterograde intraflagellar transport and tubulin cargo binding for cilia assembly

Key Binding Partner

IFT81 (forms a tubulin-binding module within IFT-B)

Disease Relevance

Mutations linked to ciliopathies including Bardet–Biedl syndrome and congenital heart defects

Research Applications

Biochemical interaction assays, structural studies, ciliopathy disease modeling, antibody development

SKU

rp374347

What Is IFT74? Biological Background and Function

Intraflagellar transport protein 74 (IFT74) is a core subunit of the IFT complex B (IFT-B), a multiprotein assembly that orchestrates the bidirectional trafficking of structural and signaling components along the ciliary axoneme. Cilia and flagella are evolutionarily conserved organelles present on the surface of most eukaryotic cells, where they perform mechanosensory, chemosensory, and motility functions essential to development and homeostasis.

IFT74 forms a tight heterodimer with IFT81, and together this module acts as a principal adaptor for polymerized and unpolymerized tubulin, the principal cargo required for axonemal elongation. The coiled-coil N-terminal region of IFT74 provides a positively charged surface that interacts with the acidic C-terminal tails of tubulin, enabling the IFT machinery to transport tubulin into the growing ciliary tip. Loss of IFT74 function leads to severely truncated or absent cilia, underscoring its indispensable role in ciliogenesis.

Beyond structural roles, IFT74 participates in the regulation of Hedgehog (Hh) signaling, a pathway critically dependent on ciliary integrity for proper signal transduction during embryonic patterning and tissue homeostasis in vertebrates.

Disease Relevance: IFT74 and Ciliopathies

Ciliopathies are a heterogeneous group of genetic disorders caused by defects in cilia structure or function. Because cilia are present in nearly every cell type in the human body, ciliopathy phenotypes are pleiotropic and can include retinal dystrophy, polycystic kidney disease, situs inversus, skeletal dysplasia, and central nervous system malformations.

Pathogenic variants in IFT74 have been reported in individuals presenting with Bardet–Biedl syndrome (BBS), a ciliopathy characterized by rod–cone dystrophy, obesity, polydactyly, renal anomalies, and cognitive impairment. Additionally, IFT74 mutations have been associated with congenital heart defects, consistent with the known role of cilia in establishing left–right body axis asymmetry during embryogenesis.

Recombinant Human IFT74 Protein enables researchers to dissect the molecular consequences of disease-associated mutations, reconstitute IFT-B subcomplexes in vitro, and develop and validate diagnostic antibodies—accelerating the understanding of ciliopathy pathomechanisms and potential therapeutic targets.

Research Applications of Recombinant Human IFT74 Protein

Recombinant Human IFT74 Protein (SKU: rp374347) supports a wide range of in vitro and cell-based experimental approaches:

• Protein–Protein Interaction Studies: IFT74 can be used in pull-down assays, co-immunoprecipitation validation experiments, and surface plasmon resonance (SPR) or bio-layer interferometry (BLI) assays to map binding interfaces within the IFT-B complex, particularly its interaction with IFT81 and tubulin.
• Structural Biology: The recombinant protein is suitable as a component for cryo-electron microscopy (cryo-EM) or X-ray crystallography studies aimed at resolving the architecture of IFT-B subcomplexes and the tubulin-transport module.
• Antibody Development and Validation: High-purity recombinant IFT74 is an ideal immunogen for raising monoclonal or polyclonal antibodies and as an ELISA coating antigen for antibody titer determination.
• Functional and Biochemical Assays: Use in tubulin-binding assays to characterize the effect of point mutations found in ciliopathy patients, enabling structure–function dissection.
• Ciliopathy Disease Modeling: Supports the development of biochemical reconstitution models of cilia assembly defects for drug screening and mechanistic studies.

Product Specifications and Handling Guidelines

Recombinant Human IFT74 Protein (SKU: rp374347) is manufactured using recombinant expression systems to ensure consistency and reproducibility across experiments. Researchers should consult the accompanying Certificate of Analysis (CoA) for lot-specific purity, concentration, and endotoxin data prior to use.

General handling recommendations:

• Reconstitute lyophilized protein according to the datasheet instructions, typically in a neutral-pH physiological buffer such as PBS.
• Avoid repeated freeze–thaw cycles; aliquot single-use volumes upon first reconstitution.
• Store at –20 °C or –80 °C as recommended; do not store in frost-free freezers that undergo temperature cycling.
• Centrifuge briefly before opening to collect contents at the bottom of the vial.
• For long-term stability, consider adding a carrier protein (e.g., 0.1% BSA) if the working concentration is very low.

Always refer to the product-specific datasheet provided with each lot for validated storage conditions, activity data, and suggested working concentrations for particular assay formats.

Frequently asked questions

What is the function of IFT74 in cilia assembly?

IFT74 is a core subunit of IFT complex B and forms a heterodimer with IFT81 that functions as the primary tubulin-transport module within the IFT machinery. This complex binds unpolymerized tubulin and transports it into the growing cilium, making IFT74 essential for axonemal elongation and cilia formation. Loss of IFT74 results in severely shortened or absent cilia.

Which diseases are associated with IFT74 mutations?

Pathogenic variants in IFT74 have been linked to ciliopathies including Bardet–Biedl syndrome, which presents with retinal dystrophy, obesity, polydactyly, and renal anomalies. IFT74 mutations have also been reported in association with congenital heart defects, reflecting the role of cilia in establishing left–right body axis asymmetry during development.

How should Recombinant Human IFT74 Protein be stored to maintain activity?

The protein should be stored at –20 °C or –80 °C as specified in the product datasheet. Repeated freeze–thaw cycles should be avoided by aliquoting the protein into single-use volumes upon first reconstitution. Always consult the Certificate of Analysis for lot-specific storage and stability recommendations.

What experimental assays is Recombinant Human IFT74 Protein validated for?

Recombinant Human IFT74 Protein is suitable for protein–protein interaction studies (pull-down, SPR, BLI), structural biology applications (cryo-EM, crystallography), antibody development and ELISA, and functional tubulin-binding assays. Researchers should verify suitability for specific assay formats by consulting the product datasheet and CoA.

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, Bhargava 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. Lindstrand A, et al. Recurrent mosaic pathogenic variants in PIGA and IFT74 cause a multiple congenital anomalies syndrome. Hum Mutat. 2016;37(9):898–910.

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