C5L2, a nonsignalling C5A receptor is uncoupled to G proteins

Abstract

The complement anaphylatoxins are prominent mediators of host defence and inflammation. The small subunit of the fifth component of complement, C5a has complex effects in vivo including potential anti- and pro-inflammatory effects in acute pancreatitis with associated lung injury, and sepsis respectively. Deletion of the classical C5a receptor C5aR, does not fully explain all these effects. Secondly, expression of receptors for C5a on parenchymal cells in the lung, liver, smooth muscle and endothelial cells serve as yet uncharacterised functions. We suspected that an additional receptor for C5a might exist. Ohno and colleagues (Ohno et al. 2000) had Just cloned a novel human gene encoding the putative orphan receptor “C5a like 2 receptor”, C5L2, which they found on immature but not mature dendritic cells. We cloned C5L2 from man and mouse and characterised this receptor.