Proteome-Wide Search Reveals Unexpected RNA-Binding Proteins in Saccharomyces cerevisiae

The vast landscape of RNA-protein interactions at the heart of post-transcriptional regulation remains largely unexplored. Indeed it is likely that, even in yeast, a substantial fraction of the regulatory RNA-binding proteins (RBPs) remain to be discovered. Systematic experimental methods can play a key role in discovering these RBPs - most of the known yeast RBPs lack RNA-binding domains that might enable this activity to be predicted. We describe here a proteome-wide approach to identify RNA-protein interactions based on in vitro binding of RNA samples to yeast protein microarrays that represent over 80% of the yeast proteome. We used this procedure to screen for novel RBPs and RNA-protein interactions. A complementary mass spectrometry technique also identified proteins that associate with yeast mRNAs. Both the protein microarray and mass spectrometry methods successfully identify previously annotated RBPs, suggesting that other proteins identified in these assays might be novel RBPs. Of 35 putative novel RBPs identified by either or both of these methods, 12, including 75% of the eight most highly-ranked candidates, reproducibly associated with specific cellular RNAs. Surprisingly, most of the 12 newly discovered RBPs were enzymes. Functional characteristics of the RNA targets of some of the novel RBPs suggest coordinated post-transcriptional regulation of subunits of protein complexes and a possible link between mRNA trafficking and vesicle transport. Our results suggest that many more RBPs still remain to be identified and provide a set of candidates for further investigation

Polyelectrolyte microcapsule arrays: preparation and biomedical applications

In the need of development of versatile and flexible platforms for sensing and other biomedical applications, micro- and nanostructured particle arrays attract strong scientific interest. In this review we focus on fabrication of arrays of polyelectrolyte layer-by-layer assembled microcapsules and bio-related applications of such arrays. A cargo encapsulated in the microcapsules can be released on demand, thus opening perspectives for biosensing, diagnostics, controlled drug delivery, and tissue engineering. Here, we also consider a new composite systemmicrocapsules embedded into polymeric filmboth components are made by the LbL technique. Fabrication approaches and perspectives in the preparation and in the use of the microcapsule arrays are addressed