Recombinant Human CCL23/MPIF-1 (aa 46-120) Protein

CCL23, also known as MPIF-1, Ck beta 8 and MIP-3, is a member of the CC chemokine subfamily that is designated CCL23. Alternative splicing of the CCL23 gene results in two mRNAs that encode a short (Ck beta 8) and a long (Ck beta 8-1) isoform of the chemokine. Ck beta 8 cDNA encodes a 120 amino acid (aa) residue precursor protein with a putative 21 aa residue signal peptide that is cleaved to generate a 99 aa residue mature Ck beta 8 (aa 22 - 120). Additional N-terminal processing of the 99 aa residue variant can generate a 75 aa residue Ck beta 8 (aa 46 - 120) that is significantly more active than the 99 aa residue variant. Similarly, Ck beta 8-1 encodes a 137 aa residue precursor protein that can give rise to a 116 and a 92 aa residue chemokine. Among CC chemokine members, CCL23 is most closely related to MIP-5/CCL15 (67% sequence identity) and MIP-1 alpha /CCL3 (51%). CCL23 mRNA is most abundant in the adult lung and liver, but is also present in bone marrow, placenta, and various myelomonocytic cell lines. CCL23 has been shown to suppress the low proliferative potential colony-forming cells that give rise to granulocyte and monocyte lineages. CCL23 binds to CCR1 with high affinity and has been shown to be a potent chemoattractant and activator of monocytes, dendritic cells, osteoclast precursors.