Cluster Of Differentiation 180 (CD180)

CD180 is a cell surface molecule consisting of extracellular leucine-rich repeats (LRR) and a short cytoplasmic tail. The extracellular LRR is associated with a molecule called MD-1 and form the cell surface receptor complex, RP105/MD-1. It belongs to the family of pathogen receptors, Toll-like receptors (TLR). RP105/MD1, by working in concert with TLR4, controls B cell recognition and signaling of lipopolysaccharide (LPS), a membrane constituent of Gram-negative bacteria.The cDNA encodes a 661-amino acid polypeptide containing a putative signal sequence, a single transmembrane region, and leucine-rich repeats in the extracellular domain. Northern blotting of human leukocyte cell lines showed that RP105 was expressed in some B cells and monocytes, but not in T cells.