Phosphorylcholine phosphatase is enhanced by a LysR regulator

MASSIMELLI, MJ; BEASSONI, PR; FORRELLAD, MA; MANSILLA, MC; BARRA, JL; DOMENECH, CE; LISA, AT

Iguazú, Misiones

Congreso; XL Reunión Anual, Sociedad Argentina de Investigación en Bioquímica y Biología Molecular (SAIB); 2004

Sociedad Argentina de Investigación en Bioquímica y Biología Molecular (SAIB)

Phosphorylcholine phosphatase (PChP) of P. aeruginosa is a enzyme that acts coordinately with haemolytic phospholipase C to break down phosphatidylcholine into choline and Pi. Recently we have found the gene responsible for this activity, named pchP. By Western blot using anti PChP antibodies we could demonstrate the presence of this protein when P. aeruginosa grows with choline, betaine, dimethylglycine, carnitine, but not with succinate/NH4. pchP gene is located at positions 5858257 to 5957208 inP. aeruginosa PAO1 genome. Upstream of pchP, a probable LysR regulator (PA5293) is located. In the present work we confirmed induction of pchP by choline or derivatives by Northern blot, and showed that pchP is transcripted monocistronically. In order to determine if probable LysR regulator located upstream of pchP is involved in regulation of this gene, we studied mutant 42488 from UWGC mutant collection, with a IsphoA/hah insertion in PA5293 gene. This mutant showed a 70% depletion of PChP activity, but nearly wild type levels were recovered when it was complemented by introduction of wild PA5293 gene in pBBR1MCS-5 vector. Western blot experiments support these observations. These results led us to propose that PA5293 gene encodes a transcriptional regulator involved in pchP activation