EFOX – FILESHARING WITH WEB SERVICES

Web Services and Peer-to-Peer are two concepts for distributed computing which gained much attention within the academic community. The former one was developed with the intention to provide interoperability within heterogeneous environments. The latter one offers a paradigm where resources are shared among participants of a network and the need for central components is minimized. This paper presents the results of a project bringing these two concepts together by means of a filesharing system. In this context different Web Service standards are analyzed with respect to their usability for Peer-to-Peer computing

Ena/VASP Proteins Cooperate with the WAVE Complex to Regulate the Actin Cytoskeleton

SummaryEna/VASP proteins and the WAVE regulatory complex (WRC) regulate cell motility by virtue of their ability to independently promote actin polymerization. We demonstrate that Ena/VASP and the WRC control actin polymerization in a cooperative manner through the interaction of the Ena/VASP EVH1 domain with an extended proline rich motif in Abi. This interaction increases cell migration and enables VASP to cooperatively enhance WRC stimulation of Arp2/3 complex-mediated actin assembly in vitro in the presence of Rac. Loss of this interaction in Drosophila macrophages results in defects in lamellipodia formation, cell spreading, and redistribution of Ena to the tips of filopodia-like extensions. Rescue experiments of abi mutants also reveals a physiological requirement for the Abi:Ena interaction in photoreceptor axon targeting and oogenesis. Our data demonstrate that the activities of Ena/VASP and the WRC are intimately linked to ensure optimal control of actin polymerization during cell migration and development

A Cell Migration Tracking Tool Supports Coupling of Tissue Rotation to Elongation

Cell migration is indispensable to morphogenesis and homeostasis. Live imaging allows mechanistic insights, but long-term observation can alter normal biology, and tools to track movements in vivo without perturbation are lacking. We develop here a tool called M-TRAIL (matrix-labeling technique for real-time and inferred location), which reveals migration histories in fixed tissues. Using clones that overexpress GFP-tagged extracellular matrix (ECM) components, motility trajectories are mapped based on durable traces deposited onto basement membrane. We applied M-TRAIL to Drosophila follicle rotation, comparing in vivo and ex vivo migratory dynamics. The rate, trajectory, and cessation of rotation in wild-type (WT) follicles measured in vivo and ex vivo were identical, as was rotation failure in fat2 mutants. However, follicles carrying intracellularly truncated Fat2, previously reported to lack rotation ex vivo, in fact rotate in vivo at a reduced speed, thus revalidating the hypothesis that rotation is required for tissue elongation. The M-TRAIL approach could be applied to track and quantitate in vivo cell motility in other tissues and organisms