Cytidylyl and uridylyl cyclase activity of bacillus anthracis edema factor and Bordetella pertussis CyaA.
Cyclic adenosine 3',5'-monophosphate (cAMP) and cyclic guanosine 3',5'-monophosphate (cGMP) are second messengers for numerous mammalian cell functions. The natural occurrence and synthesis of a third cyclic nucleotide (cNMP), cyclic cytidine 3',5'-monophosphate (cCMP), is a matter of controversy, and almost nothing is known about cyclic uridine 3',5'-monophosphate (cUMP). Bacillus anthracis and Bordetella pertussis secrete the adenylyl cyclase (AC) toxins edema factor (EF) and CyaA, respectively, weakening immune responses and facilitating bacterial proliferation. A cell-permeable cCMP analogue inhibits human neutrophil superoxide production. Here, we report that EF and CyaA also possess cytidylyl cyclase (CC) and uridylyl cyclase (UC) activity. CC and UC activity was determined by a radiometric assay, using [alpha-(32)P]CTP and [alpha-(32)P]UTP as substrates, respectively, and by a high-performance liquid chromatography method. The identity of cNMPs was confirmed by mass spectrometry. On the basis of available crystal structures, we developed a model illustrating conversion of CTP to cCMP by bacterial toxins. In conclusion, we have shown both EF and CyaA have a rather broad substrate specificity and exhibit cytidylyl and uridylyl cyclase activity. Both cCMP and cUMP may contribute to toxin actions.
Department of Pharmacology and Toxicology, Institute of Pharmacy, University of Regensburg, Regensburg, Germany.
Martin
M
Göttle
Stefan
S
Dove
Frieder
F
Kees
Jens
J
Schlossmann
Jens
J
Geduhn
Burkhard
B
König
Yuequan
Y
Shen
Wei-Jen
WJ
Tang
Volkhard
V
Kaever
Roland
R
Seifert
D037361:Adenylate Cyclase Toxin / Q000378:metabolism*; D000942:Antigens, Bacterial / Q000378:metabolism*; D001427:Bacterial Toxins / Q000378:metabolism*; D000242:Cyclic AMP / Q000378:metabolism; D006801:Humans; D007109:Immunity; D009712:Nucleotides, Cyclic / Q000378:metabolism; D019761:Phosphorus-Oxygen Lyases / Q000378:metabolism*; D013379:Substrate Specificity; D014542:Uridine Monophosphate / Q000378:metabolism
D037361:Adenylate Cyclase Toxin; D000942:Antigens, Bacterial; D001427:Bacterial Toxins; D009712:Nucleotides, Cyclic; C030325:anthrax toxin; C045338:cyclic 3',5'-uridine monophosphate; D000242:Cyclic AMP; D014542:Uridine Monophosphate; D019761:Phosphorus-Oxygen Lyases; C019978:cytidylate cyclase