RNP localization and transport in yeast

The localization of mRNAs is used by various types of polarized cells to lo cally translate specific proteins, which restricts their distribution to a particular sub-region of the cytoplasm. This mechanism of protein sorting i s involved in major biological processes such as asymmetric cell division, oogenesis, cellular motility, and synapse formation. With the finding of lo calized mRNAs in the yeast Saccharomyces cerevisiae, it is now possible to benefit from the powerful yeast laboratory tools to explore the molecular b asis of RNA localization. Because mRNA transport and localization in yeast share many features with RNA localization in higher eukaryotes, including t he formation of a large ribonucleoprotein (RNP) localization complex, the r equirement of a polarized cytoskeleton and molecular motors, and the role o f nuclear RNA-binding proteins in cytoplasmic localization, the yeast can b e used as a paradigm for unraveling the molecular aspects of this process. This review summarizes the current knowledge on RNP transport and localizat ion in yeast.