Placenta Specific Protein 8 (PLAC8)

PLAC8 expression was downregulated upon activation, particularly in dendritic cells generated in vitro from CD34 progenitor cells.The deduced 115-amino acid protein contains a cleavable 23-amino acid signal peptide and no transmembrane domain. PLAC8 shares 83% homology with mouse Plac8, which contains 112 amino acids. The human sequence conserves 15 of the 16 cysteine residues found in the mouse protein. PLAC8 expression in all leukocyte populations tested, with weaker expression in monocyte-derived dendritic cells. Northern blot analysis detected a major transcript of 0.7 kb and minor transcripts of 4.4 and 7 kb in organs of the immune system. High expression was found in spleen, lymph nodes, peripheral blood leukocytes, and bone marrow, with lower expression in thymus, appendix, and fetal liver.