A new strategy to disrupt the host cytoskeleton by the pathogen Legionella pneumophila
Title: A new strategy to disrupt the host cytoskeleton by the pathogen Legionella pneumophila
Description of the finding: A new study published in the journal PLOS Pathogens by the Luo lab reveals that the bacterial pathogen Legionella pneumophila attacks the host cell by cleaving actin, an essential component of the cytoskeleton of eukaryotic cells important for their shape and other important cellular processes. The digestion of actin is performed by a protein called RavK, one of the many virulence factors the bacterium uses to counteract the pathogen killing strategy of the host. Cleaved actin lost the ability to form polymers, which is important for its activity. Understanding the mechanism of bacterial virulence is important for the development of novel anti-infective agents and for better appreciation of host cell biology.
Yao Liu, a graduate student in the Luo lab is the first author of the paper; former graduate students Wenhan Zhu and Yunhao Tan, Ernesto S. Nakayasu at Pacific Northwest National Laboratory, Richland, WA and Christopher J. Staiger contributed to the study.
Cleavage by RavK inhibits actin polymerization. A. Cleavage by RavK inhibited actin polymerization in actin sedimentation assay. After treatment with RavK or its mutant, actin polymerization was allowed to proceed. B. Quantification of the percentage of polymerized actin versus total actin. C. Cleavage by RavK inhibited actin polymerization in a kinetic assembly assay. D. Actin used in pyrene-labeled actin polymerization assay. Groups: i, actin treated with RavK; ii, actin treated with RavKH95A; iii, actin without treatment. Lanes: I, input; P, pellet; S, supernatant.