Open AccessLocalization of protein kinase C ε to macrophage vacuoles perforated by Listeria monocytogenes cytolysin
Author(s) -
Shaughnessy Lee M.,
Lipp Peter,
Lee KyungDall,
Swanson Joel A.
Publication year - 2007
Publication title -
cellular microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.542
H-Index - 138
eISSN - 1462-5822
pISSN - 1462-5814
DOI - 10.1111/j.1462-5822.2007.00903.x
Subject(s) - vacuole , protein kinase c , listeriolysin o , microbiology and biotechnology , biology , phagosome , cytolysin , phospholipase c , cytoplasm , phagocytosis , organelle , diacylglycerol kinase , endocytic cycle , kinase , listeria monocytogenes , biochemistry , signal transduction , endocytosis , listeria , cell , virulence , genetics , bacteria , gene
Summary Three proteins secreted by Listeria monocytogenes facilitate escape from macrophage vacuoles: the cholesterol‐dependent cytolysin listeriolysin O (LLO), a phosphoinositide‐specific phospholipase C (PI‐PLC) and a broad‐range phospholipase C (PC‐PLC). LLO and PI‐PLC can activate several members of the protein kinase C (PKC) family during infection. PKCε is a novel PKC that contributes to macrophage activation, defence against bacterial infection, and phagocytosis; however, a role for PKCε in Lm infections has not been described. To study PKCε dynamics, PKCε‐YFP chimeras were visualized in macrophages during Lm infection. PKCε‐YFP was recruited to forming vacuoles during macrophage phagocytosis of Lm and again later to fully formed Lm vacuoles. The PKCε‐YFP localization to the fully formed Lm vacuole was LLO‐dependent but independent of PI‐PLC or PC‐PLC. PKCε‐YFP recruitment often followed LLO perforation of the membrane, as indicated by localization of PKCε‐YFP to Lm vacuoles after they released small fluorescent dyes into the cytoplasm. PKCε‐YFP recruitment to vesicles also followed phagocytosis of LLO‐containing liposomes or osmotic lysis of endocytic vesicles, indicating that vacuole perforation by LLO was the chief cause of the PKCε response. These studies implicate PKCε in a cellular mechanism for recognizing damaged membranous organelles, including the disrupted vacuoles created when Lm escapes into cytoplasm.