CD180 Gene (LY64): Function, Expression, and Clinical Significance

The CD180 gene encodes a type I transmembrane glycoprotein that is a member of the Toll-like receptor (TLR) family, though it lacks the characteristic leucine-rich repeat (LRR) signaling domain found in other TLRs. CD180 is primarily expressed on mature B cells, monocytes, and dendritic cells. It forms a complex with the protein MD-1 (also known as LY86) on the cell surface. This complex is involved in the recognition of lipopolysaccharide (LPS) and plays a role in B-cell activation and the regulation of innate immune responses. CD180 signaling is important for the proliferation and survival of B cells and for the production of antibodies. It also modulates the response of antigen-presenting cells to microbial stimuli.

Tissue Expression

Cell Line Expression

Hotspot Mutations

Mutation functional classification

• Toll-like receptor signaling pathway

• B cell receptor signaling pathway

• MyD88-independent TLR signaling pathway

• Innate Immune System

CD180 (RP105) is a type I transmembrane protein of 661 amino acids with a large extracellular domain containing leucine-rich repeats (LRRs) and a short cytoplasmic tail lacking a Toll/IL-1 receptor (TIR) domain. It is structurally similar to TLR4 but does not signal through the classical TLR pathway. CD180 associates non-covalently with the small secreted protein MD-1 (LY86) to form a functional complex. This complex recognizes LPS and other microbial components, leading to B-cell activation, proliferation, and antibody production. CD180 signaling is also important for the survival of B cells and for the regulation of innate immune responses in monocytes and dendritic cells. The protein is heavily glycosylated and localizes to the cell surface.