CD55 Lysate – Tissue Lysate

This gene encodes a glycoprotein involved in the regulation of the complement cascade. Binding of the encoded protein to complement proteins accelerates their decay, thereby disrupting the cascade and preventing damage to host cells. Antigens present on this protein constitute the Cromer blood group system (CROM). Alternative splicing results in multiple transcript variants. The predominant transcript variant encodes a membrane-bound protein, but alternatively spliced transcripts may produce soluble proteins. [provided by RefSeq, Jul 2014]

CD55: This protein recognizes C4b and C3b fragments that condense with cell-surface hydroxyl or amino groups when nascent C4b and C3b are locally generated during C4 and c3 activation. Interaction of daf with cell-associated C4b and C3b polypeptides interferes with their ability to catalyze the conversion of C2 and factor B to enzymatically active C2a and Bb and thereby prevents the formation of C4b2a and C3bBb, the amplification convertases of the complement cascade. Belongs to the receptors of complement activation (RCA) family. 2 isoforms of the human protein are produced by alternative splicing.

Protein type: Membrane protein, GPI anchor; Cell surface

Chromosomal Location of Human Ortholog: 1q32

Cellular Component: cell surface; integral to plasma membrane; extracellular region; plasma membrane; lipid raft

Molecular Function: viral receptor activity; protein binding; lipid binding

Biological Process: respiratory burst; entry of virus into host cell; elevation of cytosolic calcium ion concentration; negative regulation of complement activation; regulation of complement activation; innate immune response; regulation of lipopolysaccharide-mediated signaling pathway; complement activation, classical pathway

Disease: Blood Group, Cromer System