CD55 Antibody – Rabbit Polyclonal

This gene encodes a protein involved in the regulation of the complement cascade. The encoded glycoprotein is also known as the decay-accelerating factor (DAF); binding of DAF to complement proteins accelerates their decay, disrupting the cascade and preventing damage to host cells. Antigens present on the DAF glycoprotein constitute the Cromer blood group system (CROM). Two alternatively spliced transcripts encoding different proteins have been identified. The predominant transcript encodes a membrane-bound protein expressed on cells exposed to plasma component proteins but an alternatively spliced transcript produces a soluble protein present at much lower levels. Additional, alternatively spliced transcript variants have been described, but their biological validity has not been determined. [provided by RefSeq, Jul 2008]

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