Agonist and antagonist dual effect of the cross-linked S19 ribosomal protein dimer in the C5a receptor-mediated respiratory burst reaction of phagocytic leukocytes.
OBJECTIVE
To examine the behavior of the crosslinked dimer of S19 ribosomal protein (RP S19), a natural C5a receptor ligand, in the C5a receptor-mediated respiratory burst reaction of monocytes and neutrophils.


METHODS
The respiratory burst reaction of leukocytes was quantitatively observed by continuous spectrophotometric measurement of the reduction of a water-soluble tetrazolium salt, WST-1.


RESULTS
The RP S19 dimer induced the respiratory burst of monocytes, but not of neutrophils. Furthermore, in neutrophils, the RP S19 dimer inhibited the reaction induced by C5a, but did not affect the formyl-Met-Leu-Phe-induced reaction. The dimer of a deletion mutant at the C-terminal portion of the RP S19 induced a respiratory burst reaction similar to the one induced by C5a, both in monocytes and neutrophils. Inversely, a chimeric fusion protein between C5a and RPS19, consisting of the addition of the 12 C-terminal amino acid residues of RP S19 after the C-terminal Arg74 of the C5a molecule, behaved similarly to the RP S19 dimer.


CONCLUSIONS
The RP S19 dimer works as an agonist and antagonist of the C5a receptor in the monocyte and the neutrophil respiratory burst reactions, respectively. The switch moiety between the antagonist and agonist of the RP S19 dimer for the C5a receptor in the induction of respiratory burst of phagocytes localizes at the C-terminal region of RP S19.
Revollo
I
I
Department of Molecular Pathology, Faculty of Medical and Pharmaceutical Sciences, Kumamoto University, 2-2-1 Honjo, Kumamoto, 860-0811, Japan. tetsu@gpo.kumamoto-u.ac.jp
Nishiura
H
H
Shibuya
Y
Y
Oda
Y
Y
Nishino
N
N
Yamamoto
T
T
D003432:Cross-Linking Reagents; D019281:Dimerization; D017353:Gene Deletion; D006801:Humans; D007962:Leukocytes / Q000378:metabolism / Q000502:physiology*; D008565:Membrane Proteins / Q000819:agonists / Q000037:antagonists & inhibitors / Q000235:genetics / Q000494:pharmacology*; D009000:Monocytes / Q000378:metabolism; D009154:Mutation; D009504:Neutrophils / Q000378:metabolism; D010446:Peptide Fragments / Q000235:genetics; D010587:Phagocytosis; D044087:Receptor, Anaphylatoxin C5a; D011951:Receptors, Complement / Q000819:agonists / Q000037:antagonists & inhibitors / Q000235:genetics; D011993:Recombinant Fusion Proteins / Q000494:pharmacology; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000494:pharmacology; D016897:Respiratory Burst / Q000187:drug effects*; D012269:Ribosomal Proteins / Q000737:chemistry / Q000235:genetics / Q000494:pharmacology*; D013778:Tetrazolium Salts
C110656:2-(4-iodophenyl)-3-(4-nitrophenyl)-5-(2,4-disulfophenyl)-2H-tetrazolium; C488033:C5AR1 protein, human; D003432:Cross-Linking Reagents; D008565:Membrane Proteins; D010446:Peptide Fragments; D044087:Receptor, Anaphylatoxin C5a; D011951:Receptors, Complement; D011993:Recombinant Fusion Proteins; D011994:Recombinant Proteins; D012269:Ribosomal Proteins; D013778:Tetrazolium Salts; C040343:ribosomal protein S19