Recombinant Human CD89 protein

Supplementary information

This supplementary information is collated from multiple sources and compiled automatically.

CD89 also known as the Fc alpha receptor (FcαR) is a protein receptor with a molecular mass of approximately 55 to 75 kDa. It is encoded by the FCAR gene and predominantly expressed on myeloid cells such as neutrophils eosinophils monocytes and some macrophages. CD89 acts as an important component of the immune system by binding to the Fc region of immunoglobulin A (IgA) facilitating various immune responses. This receptor mediates diverse immune functions by activating cellular responses upon IgA ligand binding.

Biological function summary

CD89 plays an important role in regulating immune surveillance and response. It associates with the gamma chain of the Fc receptor complex which is necessary for its signaling ability. The binding of IgA to CD89 triggers various processes including phagocytosis antibody-dependent cellular cytotoxicity (ADCC) and the release of pro-inflammatory cytokines. These processes are fundamental for host defense against pathogens particularly those entering through mucosal surfaces where IgA is typically abundant.

Pathways

CD89 is part of the immune effector pathway and participates actively in the immunoregulatory signaling cascade. One significant pathway is the IgA-mediated immune response pathway where CD89 cooperates with other Fc receptors and integrins to clear infections. Additionally its interaction with the complement system enhances opsonization and pathogen elimination. Related proteins in these pathways include other Fc receptors like FcγR which share similar signaling mechanisms and immune functions.

CD89 is associated with conditions involving dysregulated immune responses or infections. For example it is implicated in IgA nephropathy where abnormal IgA deposits in the kidneys may trigger inflammation through CD89-mediated pathways. Furthermore alterations in CD89 expression or function have been studied in the context of inflammatory bowel disease (IBD) illustrating the receptor's role in aberrant immune responses. The target’s interaction with proteins such as IgA and complement C3 provides insight into its involvement in these pathological conditions.