Recombinant Mouse IL3

IL-3 is produced mainly by T cells following cell activation by antigens and mitogens, but also by keratinocytes, natural killer cells, mast cells, endothelial cells, and monocytes. The analysis of bacterial-derived recombinant IL-3 shows that glycosylation is not required for the activity of IL-3. IL-3 sequences are evolutionarily less well conserved. Human and murine IL-3 show approximately 29% homology at the protein level while murine and rat IL-3 show approximately 54% homology. IL-3-alpha and IL-3-beta are two isoforms of rat IL-3. IL-3 receptors are expressed on macrophages, mast cells, eosinophils, megakaryocytes, basophils, bone marrow progenitor cells, and various myeloid leukemia cells. IL-3/receptor complexes have a Kdis of 10-9 - 10-10 M. Binding of IL-3 to its receptor causes specific phosphorylation of a 150 kDa membrane glycoprotein.