Amino acids 327-350 of the human C5a-receptor are not essential for [125I]C5a binding in COS cells and signal transduction in Xenopus oocytes.
The anaphylatoxic peptide C5a is an important inflammatory mediator of the complement system. We have generated human C5a-receptor (hC5aR) mutants with truncation of its cytosolic carboxyl-terminus (C-terminus). Both mutants were analysed for C5a-binding in transiently expressing COS cells, and one mutant additionally for GTP-binding regulatory protein (G-protein) coupling in cRNA-injected Xenopus oocytes. Our data suggest that (a) amino acids (aa) 314 to 326 as part of the C-terminus are necessary for proper receptor folding or expression and (b) the receptor C-terminus distal from position 327 is not critical for receptor expression, folding, binding and G-protein coupling.
Klos
A
A
Institut für Medizinische Mikrobiologie, Medizinische Hochschule Hannover, Germany.
Mätje
C
C
Rheinheimer
C
C
Bautsch
W
W
Köhl
J
J
Martin
U
U
Burg
M
M
D000818:Animals; D001483:Base Sequence; D001667:Binding, Competitive; D002460:Cell Line; D015936:Complement C5a / Q000378:metabolism*; D005260:Female; D019204:GTP-Binding Proteins / Q000502:physiology; D015870:Gene Expression; D006801:Humans; D007700:Kinetics; D008969:Molecular Sequence Data; D009865:Oocytes / Q000378:metabolism*; D010446:Peptide Fragments / Q000737:chemistry / Q000378:metabolism*; D044087:Receptor, Anaphylatoxin C5a; D011951:Receptors, Complement / Q000737:chemistry* / Q000235:genetics / Q000502:physiology; D015398:Signal Transduction / Q000502:physiology*; D013329:Structure-Activity Relationship; D014162:Transfection; D014982:Xenopus laevis
D010446:Peptide Fragments; D044087:Receptor, Anaphylatoxin C5a; D011951:Receptors, Complement; D015936:Complement C5a; D019204:GTP-Binding Proteins