The Spectrin Cytoskeleton Is Crucial for Adherent and Invasive Bacterial Pathogenesis

Various enteric bacterial pathogens target the host cell cytoskeletal machinery as a crucial event in their pathogenesis. Despite thorough studies detailing strategies microbes use to exploit these components of the host cell, the role of the spectrin-based cytoskeleton has been largely overlooked. Here we show that the spectrin cytoskeleton is a host system that is hijacked by adherent (Entropathogenic Escherichia coli [EPEC]), invasive triggering (Salmonella enterica serovar Typhimurium [S. Typhimurium]) and invasive zippering (Listeria monocytogenes) bacteria. We demonstrate that spectrin cytoskeletal proteins are recruited to EPEC pedestals, S. Typhimurium membrane ruffles and Salmonella containing vacuoles (SCVs), as well as sites of invasion and comet tail initiation by L. monocytogenes. Spectrin was often seen co-localizing with actin filaments at the cell periphery, however a disconnect between the actin and spectrin cytoskeletons was also observed. During infections with S. Typhimurium ΔsipA, actin-rich membrane ruffles at characteristic sites of bacterial invasion often occurred in the absence of spectrin cytoskeletal proteins. Additionally, early in the formation of L. monocytogenes comet tails, spectrin cytoskeletal elements were recruited to the surface of the internalized bacteria independent of actin filaments. Further studies revealed the presence of the spectrin cytoskeleton during SCV and Listeria comet tail formation, highlighting novel cytoplasmic roles for the spectrin cytoskeleton. SiRNA targeted against spectrin and the spectrin-associated proteins severely diminished EPEC pedestal formation as well as S. Typhimurium and L. monocytogenes invasion. Ultimately, these findings identify the spectrin cytoskeleton as a ubiquitous target of enteric bacterial pathogens and indicate that this cytoskeletal system is critical for these infections to progress

Spectrin-based skeleton as an actor in cell signaling

This review focuses on the recent advances in functions of spectrins in non-erythroid cells. We discuss new data concerning the commonly known role of the spectrin-based skeleton in control of membrane organization, stability and shape, and tethering protein mosaics to the cellular motors and to all major filament systems. Particular effort has been undertaken to highlight recent advances linking spectrin to cell signaling phenomena and its participation in signal transduction pathways in many cell types

Una Nueva Plaga en República Dominicana: Frankiniella occidentalis (Pergande, 1985) (Thysanoptera, Thripidae)

Procedente del oeste de Norte América, es introducido en Europa en 1985 y desde esta fecha en numerosos otros países del mundo, Flankliniella occidentalis (Pergande) fue encontrado por primera vez en República Dominicana, en abril de 1992. Polífago y vector del TSWV (Tomato Spotted Wilt Virus) en numerosas hortalizas y cultivos ornamentales. Este thrips es actualmente difícil de controlar tanto en cultivo de campo como en cultivo de invernadero

Thysanoptera of the Galápagos Islands

v. ill. 23 cm.Also available through BioOne: http://www.bioone.org/doi/abs/10.2984/65.4.507QuarterlyThysanoptera from the Galápagos Islands were inventoried from 627 slide-mounted specimens that were made with material that had been stored at the Reference Collection of Terrestrial Invertebrates at the Charles Darwin Research Station, Galápagos, Ecuador. Museum material was complemented by field collections conducted over the period October – November 2009. This inventory was augmented from records in the published literature. Identification of museum and field-collected material added an additional 27 species to the already known fauna, an increase of 54%. A total of 77 species of thrips from 42 genera in four families is now known from 17 different islands in the Galápagos. At least nine species are serious pests, of which four, Frankliniella occidentalis, Gynaikothrips uzeli, Thrips palmi, and Thrips tabaci, are reported from the Galápagos Islands in the primary scientific literature for the first time