Bcakground Interleukin 1 (IL-1) , is a name that designates two proteins, IL-1 alpha and IL-1 beta, which are the products of distinct genes, but which show approximately 25% amino acid sequence identity and which recognize the same cell surface receptors. Although IL-1 production is generally considered to be a consequence of inflammation, recent evidence suggests that IL-1 is also temporarily upregulated during bone formation and the menstrual cycle and can be induced in response to nervous system stimulation. In response to classic stimuli produced by inflammatory agents, infections or microbial endotoxins, a dramatic increase in the production of IL-1 by macrophages and various other cells is seen. Cells in particular known to produce IL-1 include osteoblasts, monocytes, macrophages, keratinocytes, Kupffer cells, hepatocytes, thymic and salivary gland epithelium, Schwann cells, fibroblasts and glia (oligodendroglia, astrocytes and microglia). IL-1 alpha and IL-1 beta are both synthesized as 31 kDa precursors that are subsequently cleaved into proteins with molecular weights of approximately17,000 Da. Neither precursor contains a typical hydrophobic signal peptide sequence and most of the precursor form of IL-1 alpha remains in the cytosol of cells, although there is evidence for a membrane-bound form of the precursor form of IL-1 alpha. The IL-1 alpha precursor reportedly shows full biological activity in the EL-4 assay. Among various species, the amino acid sequence of mature IL-1 alpha is conserved 60% to 70% and human IL-1 has been found to be biologically active on murine cell lines. Both forms of IL-1 bind to the same receptors, designated type I and type II. Evidence suggests that only the type I receptor is capable of signal transduction and that the type II receptor may function as a decoy, binding IL-1 and thus preventing binding of IL-1 to the type I receptor. Reference 1. Nicklin MJ,et al. (1994) Genomics. 19(2):382-4. 2. March CJ, et al. (1985) Nature. 315(6021):641-7. 3. Bankers-Fulbright JL, et al. (1996) Life Sci. 59(2):61-83. 4. Dinarello CA, et al. (1997) Semin Oncol. 24 (3 Suppl 9):S9-81-S9-93. Specifications Synonyms Hematopoietin-1; IL1 alpha; IL-1 alpha; IL1; IL1A; IL-1A; IL1-ALPHA; IL1F1; IL-1F1;BAF Accession # Q53QF9 Source Human embryonic kidney cell, HEK293-derived human IL-1 alpha/IL-1F1 protein Ser113-Ala271 Predicted Moleucular weight 18.0 kDa Components and Storage Formulation Solution protein. Dissolved in sterile PBS buffer. This solution can be diluted into other aqueous buffers. Centrifuge the vial prior to opening. Storage and Stability Avoid repeated freeze-thaw cycles. It is recommended that the protein be aliquoted for optimal storage. 12 months from date of receipt, -20 to -70 °C as supplied. Shipping Shipping with dry ice. Quality Purity > 95%, determined by SDS-PAGE. Endotoxin Level
