SDF-1 alpha, CXCL12, human: SDF-1α and SDF-1β, members of the chemokine α 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.
SDF-1α and SDF-1β cDNAs encode precursor proteins of 89 and 93 amino acid residues, respectively.
Both SDF-1α and SDF-1β 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-1β and absent from SDF-1α.
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., UnitProt ID: P48061