Recombinant Mouse CXCL12/SDF-1 alpha Protein

SDF-1 alpha and SDF-1 beta, members of the chemokine alpha subfamily that lack the ELR domain, were initially identified using the signal sequence trap cloning strategy from a mouse bone-marrow stromal cell line. These proteins were subsequently also cloned from a human stromal cell line as cytokines that supported the proliferation of a stromal cell‑dependent pre-B-cell line, and were named Pre‑B‑Cell Growth Stimulating Factor (PBSF). SDF‑1 alpha and SDF‑1 beta cDNAs encode precursor proteins of 89 and 93 amino acid residues, respectively. Both SDF-1 alpha and SDF‑1 beta are encoded by a single gene and arise by alternative splicing. The two proteins are identical except for the four amino acid residues that are present in the carboxy‑terminus of SDF-1 beta and absent from SDF‑1 alpha. SDF‑1/PBSF is highly conserved between species, with only one amino acid substitution between the mature human and mouse proteins. SDF‑1/PBSF acts via the chemokine receptor CXCR4 and has been shown to be a chemoattractant for T‑lymphocytes, monocytes, pro- and pre- B cells, but not neutrophils. Mice lacking SDF-1 or CXCR4 have been found to have impaired B‑lymphopoiesis, myelopoiesis, vascular development, cardiogenesis and abnormal neuronal cell migration and patterning in the central nervous system.