Reining in RNA

Abstract

Figure 1. The first joint EMBO/FASEB Workshop on Intracellular RNA Localization and Localized Translation took place between 1 and 6 July 2007, in Il Ciocco, Italy, and was organized by A. Ephrussi, E. Gavis, D. Ish‐Horowicz and J. Richter. Originally a biannual FASEB summer research conference, it is anticipated that the joint meeting will in future alternate between sites in Europe and the USA. Intracellular RNA localization and localized translation are involved in diverse processes such as embryonic patterning in Drosophila , jellyfish, tunicates, frogs and fish; the asymmetrical partitioning of fates in Drosophila neural stem cells and yeast mating types; fibroblast and neuronal growth cone motility; and synapse function (St Johnston, 2005; Du et al , 2007; Jambhekar & Derisi, 2007). The subjects discussed at this meeting included structural insights into RNA localization, improved methods for live imaging of RNA transport, and the combination of genome‐wide screens and biochemical approaches to identify localized RNAs and localization factors. Here, we highlight some of the crucial findings that were presented. Drosophila melanogaster has been widely used as a model organism to study mRNA localization and localized translation. This reflects the importance of these processes during Drosophila embryogenesis and the success of genetic screens in this organism. Indeed, visual screening methods continue to be used for the identification of new localization factors. For example, in a screen for new factors controlling microtubule organization in the fly oocyte, A. Guichet (Paris, France) found that the phosphatidylinositol‐4‐phosphate 5‐kinase (PIP5K) Skittles is necessary for phosphatidylinositol 4,5‐bisphosphate (PIP2) production and subsequent microtubule polarization, as well as for actin organization at the cortex. A. Ephrussi (Heidelberg, Germany) used a protein‐trap screen to identify Drosophila heterogeneous nuclear ribonucleoprotein 1/polypyrimidine tract binding protein 1 (hnRNP1/PTB) as a new component of the oskar ( osk ) RNP complex. Oocytes of ptb mutants show …