This Article Full Text (OnlineFirst PDF) All Versions of this Article: 1087057109341407v1 14/9/1067    most recent Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Add to Saved Citations Download to citation manager Request Permissions Request Reprints Add to My Marked Citations Citing Articles Citing Articles via Scopus Google Scholar Articles by van Lith, L. H. Articles by Zaman, G. J. R. PubMed PubMed Citation Articles by van Lith, L. H. Articles by Zaman, G. J. R. Social Bookmarking                         What's this?

C5a-Stimulated Recruitment of -Arrestin2 to the Nonsignaling 7-Transmembrane Decoy Receptor C5L2

^* To whom correspondence should be addressed. E-mail: guido.zaman{at}spcorp.com.

	Abstract

C5L2 (or GPR77) is a high-affinity receptor for the complement fragment C5a and its desarginated product, C5a-desArg. Unlike the classical C5a receptor CD88, C5L2 does not couple to intracellular G-protein-signaling pathways but is thought to function as a decoy receptor. The authors show that stimulation of C5L2 with C5a and C5a-desArg induces redistribution of green fluorescent protein–labeled -arrestin2 to cytoplasmic vesicles. C3a and C3a-desArg were inactive in the -arrestin translocation assay. Direct interaction of ligand-stimulated C5L2 with -arrestin was confirmed using a novel -galactosidase fragment complementation assay. In this assay, C5L2 was labeled with a mutationally altered peptide fragment of -galactosidase, whereas -arrestin2 was labeled with a corresponding deletion mutant of the enzyme. Stable transfection of the modified C5L2 and subsequent stimulation with C5a or C5a-desArg restored -galactosidase activity in a dose-dependent manner. The subnanomolar potency of -arrestin coupling in the -galactosidase fragment complementation assay is in agreement with the affinity of the receptor-ligand interaction. C5L2 is the first example of a 7-transmembrane decoy receptor that couples to -arrestin in a ligand-dependent manner. This observation supports the notion that G-protein-signaling and -arrestin coupling can be 2 separate activities of 7-transmembrane receptors. Furthermore, the -arrestin assays described in this article provide methods of screening for selective C5L2 modulators. (Journal of Biomolecular Screening XXXX:xxx-xxx)

First published on July 29, 2009, doi:10.1177/1087057109341407

Journal of Biomolecular Screening 2009;14:1067.

A more recent version of this article appeared on October 1, 2009


CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    Twitter    What's this?