A Feedback Loop between Dynamin and Actin Recruitment during Clathrin-Mediated Endocytosis

A live-cell imaging study reveals that a positive feedback loop between dynamin and actin contributes to efficient endocytic membrane scission

Outbreak of Salmonella Enteritidis phage type 13a infection in Sweden linked to imported dried-vegetable spice mixes, December 2014 to July 2015

From 24 December to 24 July 2015, 174 cases were reported in a nationwide salmonellosis outbreak in Sweden: 108 cases were connected to a single restaurant. A spice mix, containing dried vegetables from the restaurant tested positive for the outbreak strain. Additional spice mixes with similar content from different suppliers also tested positive. The outbreak investigation suggests there could be a risk of contaminated products being also on the market in other countries. </jats:p

A Dynamin Mutant Defines a Superconstricted Prefission State

SummaryDynamin is a 100 kDa GTPase that organizes into helical assemblies at the base of nascent clathrin-coated vesicles. Formation of these oligomers stimulates the intrinsic GTPase activity of dynamin, which is necessary for efficient membrane fission during endocytosis. Recent evidence suggests that the transition state of dynamin’s GTP hydrolysis reaction serves as a key determinant of productive fission. Here, we present the structure of a transition-state-defective dynamin mutant K44A trapped in a prefission state at 12.5 Å resolution. This structure constricts to 3.7 nm, reaching the theoretical limit required for spontaneous membrane fission. Computational docking indicates that the ground-state conformation of the dynamin polymer is sufficient to achieve this superconstricted prefission state and reveals how a two-start helical symmetry promotes the most efficient packing of dynamin tetramers around the membrane neck. These data suggest a model for the assembly and regulation of the minimal dynamin fission machine

Actin puts the squeeze on Drosophila glue secretion

International audienc