Cryptococcus neoformans is a human fungal pathogen that undergoes a dimorphic transition from a unicellular yeast to multicellular hyphae during opposite sex (mating) and unisexual reproduction (same-sex mating). Opposite- and same-sex mating are induced by similar environmental conditions and involve many shared components, including the conserved pheromone sensing Cpk1 MAPK signal transductio...

Mass spectrometry (MS) for the detection of proteins is an indispensable tool for evaluating the biological processes of the proteome. Proteomics frequently requires proteolysis of proteins into peptide fragments. Proteins can be refractory to ideal proteolysis at the sequence level rendering them difficult to analyze by routine proteomics methods. EsxA (ESAT-6, Early Secreted Antigen, 6kDa) is...

The LcrV protein (V-antigen) is a multifunctional virulence factor in Yersinia pestis, the causative agent of plague. LcrV regulates the translocation of cytotoxic effector proteins from the bacterium into the cytosol of mammalian cells via a type III secretion system, possesses antihost activities of its own, and is also an active and passive mediator of resistance to disease. Although a cryst...

Post-transcriptional gene silencing (PTGS) is a homology-dependent RNA degradation process that may target RNA exclusively in the cytoplasm. In plants, PTGS functions as a natural defense mechanism against viruses. We reported previously that the 2b protein encoded by cucumber mosaic cucumovirus (CMV) is a virulence determinant and a suppressor of PTGS initiation in transgenic Nicotiana bentham...

The Cmr1 gene in peppers confers resistance to Cucumber mosaic virus isolate-P0 (CMV-P0). Cmr1 restricts the systemic spread of CMV strain-Fny (CMV-Fny), whereas this gene cannot block the spread of CMV isolate-P1 (CMV-P1) to the upper leaves, resulting in systemic infection. To identify the virulence determinant of CMV-P1, six reassortant viruses and six chimeric viruses derived from CMV-Fny a...

The expression of the type III secretion system-a main determinant of virulence in Shigella-is controlled by regulator cascades VirF-InvE (VirB) and CpxAR two-component system. A screen for mutants that restore virulence in the cpxA background led to the isolation of a mutant of rodZ, a cytoskeletal protein that maintains the rod-shaped morphology of bacilli. InvE is normally repressed at 30 °C...

The initial binding of bacteria to host cells is crucial to the delivery of virulence factors and thus is a key determinant of the pathogen's success. We report a multivalent adhesion molecule (MAM) that enables a wide range of gram-negative pathogens to establish high-affinity binding to host cells during the early stages of infection. MAM7 binds to the host by engaging in both protein-protein...

Chronic infection with the Gram-negative bacterium Helicobacter pylori is a major risk factor for the development of gastric cancer. Accumulating evidence indicates that the H. pylori virulence determinant cytotoxin-associated gene A (CagA) has a key oncogenic role in the process. Certain biological activities of CagA require its tyrosine phosphorylation by host cell kinases. In this issue of t...