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ExoY from Pseudomonas aeruginosa , a preferential guanylyl and uridylyl cyclase (610.2)
Author(s) -
Seifert Roland,
Beckert Ulrike,
Frank Dara
Publication year - 2014
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.28.1_supplement.610.2
Subject(s) - adenylyl cyclase , type three secretion system , anthrax toxin , chemistry , biochemistry , biology , enzyme , virulence , recombinant dna , gene , fusion protein
ExoY from Pseudomonas aeruginosa is injected into host cells via the type III secretion system (Yahr TL et al. , Proc Natl Acad Sci USA 95: 13899 (1998)). ExoY is structurally similar to CyaA from Bordetella pertussis and edema factor (EF) from Bacillus anthracis . CyaA and EF are nucleotidyl cyclases with a broad substrate specificity, producing cyclic AMP, and, to a much lesser extent, cyclic GMP, cyclic UMP and cyclic CMP (Beste KY et al. , PLoS ONE 8: e70223 (2013)). These data prompted us to test the hypothesis whether ExoY is a nucleotidyl cyclase, too. For analysis of cyclic nucleotides, we used a highly specific and sensitive high‐performance liquid chromatography/tandem mass spectrometry (HPLC‐MS/MS) method. As model system, we studied rat B103 neuroblastoma cells. Transfection of B103 cells with ExoY, but not the catalytically inactive mutant ExoY‐K81M, resulted in massive increases in cyclic GMP and cyclic UMP. Similar data were obtained when B103 cells were infected with ExoY‐expressing Pseudomonas aeruginosa . ExoY induced necrosis of B103 cells. The effects of ExoY were mimicked by membrane‐permeable acetoxymetylesters of cyclic GMP and cyclic UMP. In marked contrast to ExoY, CyaA and EF preferentially increased cyclic AMP in B103 cells. In conclusion, ExoY is a nucleotidyl cyclase with a unique substrate‐specificity, and cyclic UMP may serve a novel role as second messenger.