Structure, function and cellular expression of complement anaphylatoxin receptors.
The past year has seen significant advances in determining the important structural-functional domains of the complement C5a anaphylatoxin receptor. The current model suggests a two-site binding motif in which part of the amino-terminal extracellular domain of the receptor is recognized first by the amino-terminal end and disulfide-linked core of the C5a ligand. This is followed by interaction of the carboxy-terminal end of C5a with a second, and as yet undefined, site on the receptor that results in activating appropriate signal transduction pathways via receptor coupled G proteins. Another recent advance has been the discovery that the C5a receptor is expressed on non-myeloid cells, suggesting that C5a confers previously unexpected functions on certain target tissue cells, including bronchial and alveolar epithelial cells, hepatocytes, astrocytes, and vascular endothelial cells.
Wetsel
R A
RA
Department of Pediatrics, Washington University School of Medicine, St Louis, Missouri 63110, USA.
D000595:Amino Acid Sequence; D000818:Animals; D003167:Complement Activation / Q000276:immunology; D015936:Complement C5a / Q000276:immunology*; D006801:Humans; D008969:Molecular Sequence Data; D011951:Receptors, Complement / Q000096:biosynthesis* / Q000276:immunology*
D011951:Receptors, Complement; D015936:Complement C5a