IBR   13079
INSTITUTO DE BIOLOGIA MOLECULAR Y CELULAR DE ROSARIO
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Carbon catabolite repression of type IV pili-dependent gliding
Autor/es:
MARCELO B. MENDEZ; ROBERTO GRAU
Lugar:
Mar del Plata, Buenos Aires, Argentina
Reunión:
Congreso; XLIII Reunión Nacional de la Sociedad Argentina de investigación en Bioquímica y Biología Molecular; 2007
Institución organizadora:
SAIB
Resumen:
C. perfringens is an anaerobic Gram-positive spore-forming bacterium responsible for the production of severe histotoxic and gastrointestinal diseases in humans and animals. Three available genome-sequenced C. perfringens strains (13, SM101 and ATCC13124) revealed that genes encoding flagellar proteins and chemotaxis genes are absent. However, those strains exhibit Type IV pili-dependent gliding motility. Since carbon catabolite regulation (CCR) has been implicated in the control of different bacterial behaviours, we investigated the effect of glucose and other metabolized carbohydrates on gliding motility. We demonstrated that CCR reduces the gliding motility of a large number of human and animal-derived pathogenic C. perfringens strains. Glucose produces a strong dose-dependent inhibition of gliding development without affecting vegetative growth. Maximum gliding inhibition was observed at a glucose concentration (1%). The inhibition of gliding development in the presence of glucose was due, at least in part, to the repression of the genes pilT and pilD, whose products are essential for TFP-dependent gliding proficiency. The inhibitory effect of glucose on pilT and pilD expression was under the control of the key regulatory protein CcpA (catabolite control protein A). The deficiency in CcpA activity restored the expression of pilT and pilD and gliding proficiency in the presence of 1% glucose. These results show that CcpA negative regulates the C. perfringens gliding motility. Furthermore, we discovered a novel positive role, in the absence of CCR, of CcpA on pilT / pilD expression and gliding proficiency.