title: Molecular cloning and characterization of the human anaphylatoxin C3a receptor.
abstract: In a human neutrophil cDNA library, an orphan G-protein-coupled receptor, HNFAG09, with 37% nucleotide identity to the C5a receptor (C5a-R, CD88) was identified. A novel feature of this gene, unlike C5a-R and other G-protein-coupled receptors, is the presence of an extraordinarily large predicted extracellular loop comprised of in excess of 160 amino acid residues between transmembrane domains 4 and 5. Northern blot analysis revealed that expression of mRNA for this receptor in human tissues, while similar, was distinct from C5a-R expression. Although there were differences in expression, transcripts for both receptors were detected in tissues throughout the body and the central nervous system. Mammalian cells stably expressing HNFAG09 specifically bound 125I-C3a and responded to a C3a carboxyl-terminal analogue synthetic peptide and to human C3a but not to rC5a with a robust calcium mobilization response. HNFAG09 encodes the human anaphylatoxin C3a receptor.
authors.affiliation: Department of Molecular Immunology, SmithKline Beecham Pharmaceuticals, King of Prussia, Pennsylvania 19406-0939, USA.
authors.forename: R S
authors.initials: RS
authors.lastname: Ames
authors.forename: Y
authors.initials: Y
authors.lastname: Li
authors.forename: H M
authors.initials: HM
authors.lastname: Sarau
authors.forename: P
authors.initials: P
authors.lastname: Nuthulaganti
authors.forename: J J
authors.initials: JJ
authors.lastname: Foley
authors.forename: C
authors.initials: C
authors.lastname: Ellis
authors.forename: Z
authors.initials: Z
authors.lastname: Zeng
authors.forename: K
authors.initials: K
authors.lastname: Su
authors.forename: A J
authors.initials: AJ
authors.lastname: Jurewicz
authors.forename: R P
authors.initials: RP
authors.lastname: Hertzberg
authors.forename: D J
authors.initials: DJ
authors.lastname: Bergsma
authors.forename: C
authors.initials: C
authors.lastname: Kumar
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D015703:Antigens, CD / Q000235:genetics; D001483:Base Sequence; D003001:Cloning, Molecular; D015926:Complement C3a / Q000378:metabolism*; D017931:DNA Primers / Q000737:chemistry; D015870:Gene Expression; D006801:Humans; D008562:Membrane Glycoproteins / Q000235:genetics; D008565:Membrane Proteins; D008969:Molecular Sequence Data; D010455:Peptides / Q000737:chemistry; D012333:RNA, Messenger / Q000235:genetics; D051381:Rats; D044087:Receptor, Anaphylatoxin C5a; D011951:Receptors, Complement / Q000235:genetics*; D011994:Recombinant Proteins; D014162:Transfection
chemical_list: D015703:Antigens, CD; D017931:DNA Primers; D008562:Membrane Glycoproteins; D008565:Membrane Proteins; D010455:Peptides; D012333:RNA, Messenger; D044087:Receptor, Anaphylatoxin C5a; D011951:Receptors, Complement; D011994:Recombinant Proteins; C085567:complement C3a receptor; D015926:Complement C3a