Killer Lineage Protein 1 (KLIP1)

KLIP1 contains an N-terminal signal sequence, followed by an extracellular domain, 5 transmembrane regions, and a cytoplasmic C-terminal sequence. It also has 3 potential protein kinase C phosphorylation sites. KLIP1 expression closely correlated with hematopoietic activity in both intra- and extra-embryonic hematopoietic sites. In day 30/32 human embryosections, KLIP1 protein expression was restricted to circulating hematopoietic cells at hematopoiesis sites. Membrane KLIP1 was expressed by fetal and adult GPA-positive erythroblasts, the fetal liver CD34-positive subset, fetal spleen, and adult bone marrow CD56 (NCAM1)-positive natural killer and CD19-positive B cells. Among mature blood cells, surface KLIP1 expression was restricted to CD56-positive natural killer cells.