Recombinant Human IL-5 Rα

IL-5 receptor alpha (IL-5 Rα), also known as CD125, is a subunit of the functional heterodimeric IL-5 receptor complex.¹ IL-5 is produced primarily by activated T cells and mast cells, and has diverse biological effects on a variety of cell types. It is a potent eosinophil differentiation and activation factor. The IL-5Rα chain is exclusively expressed by eosinophils, some basophils and murine B1 cells or B cell precursors.² The high affinity receptor complex for IL-5 consist of the ligand binding α chain, IL-5 Rα, and the common beta chain, CD131.³ The α-chain exclusively binds IL-5 and the intra-cellular portion of IL-5 Rα is associated with JAK2, a protein tyrosine-kinase essential in IL-5 signal transduction.^4,5 The beta subunit is shared with the high affinity receptor complexes IL-3 and GM-CSF. Like many other cytokine receptors, alternative splicing of the IL-5Rα gene results in expression of either a membrane bound or soluble form. The soluble form does not lead to signal transduction and therefore has an antagonistic effect on IL-5 signaling. Soluble IL-5 Rα up-regulation has been shown to be involved with the eosinophil-associated disease nasal polyposis.⁶

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Asp21

Lyophilized

The predicted molecular weight of Recombinant Human IL-5 Rα is Mr 38 kDa. However, the actual molecular weight as observed by migration on SDS-PAGE is Mr 43 kDa.

38

This recombinant protein was 0.2 µm filtered and lyophilized from modified Dulbecco’s phosphate buffered saline (1X PBS) pH 7.2 – 7.3 with no calcium, magnesium, or preservatives.

This lyophilized protein is stable for six to twelve months when stored desiccated at -20°C to -70°C. After aseptic reconstitution, this protein may be stored at 2°C to 8°C for one month or at -20°C to -70°C in a manual defrost freezer. Avoid Repeated Freeze Thaw Cycles. See Product Insert for exact lot specific storage instructions.

Next Day Ambient

1. Graham, A. et al. (2000) Cytokine 12:858
2. Coffer, PJ. et al. (2001) Cytokine Growth Factor Rev 12:19
3. Fiers, W. et al. (1991) Cell 66:1175
4. Ishikawa, T. et al. (1998) Blood 91:2264
5. Takatsu, K. et al. (1994) J. Exp. Med. 14:7404
6. Tavernier, J. et al. (2003) Allergy 58:371