Acidic stress induces autolysis by a CSP-independent ComE pathway in Streptococcus pneumoniae

GERMAN PIÑAS, PAULO R. CORTES, ANDREA ALBARRACÍN ORIO, JOSÉ ECHENIQUE

SGM

Lugar: Londres; Año: 2008 vol. 154 p. 1300 - 1300

font face="AdvP4AD05B" size="1"> In Streptococcus pneumoniae, autolysis is considered a programmed cell-death process executed principally by the major autolysin (LytA), and the underlying mechanism causing its activation is not completely understood. It is known that autolysis is triggered by competence development at alkaline pH and regulated by a two-component system, ComDE, which senses a competence-stimulating peptide (CSP) and behaves as a quorum-sensing mechanism. In this work, we found that acidic stress triggered a LytA-mediated autolysis and, curiously, this phenomenon was regulated by a CSP-independent ComE pathway. A further analysis of a hyperactive ComD mutant revealed that ComE needs to be phosphorylated to activate acidic