Project description:Yeast large ribosomal subunit (LSU) precursors are subject to substantial changes in protein composition during their maturation due to coordinated transient interactions with a large number of ribosome biogenesis factors and due to the assembly of ribosomal proteins. These compositional changes go along with stepwise processing of LSU rRNA precursors and with specific rRNA folding events, as revealed by recent cryo-electron microscopy analyses of late nuclear and cytoplasmic LSU precursors. Here we aimed to analyze changes in the spatial rRNA surrounding of selected ribosomal proteins during yeast LSU maturation. For this we combined a recently developed tethered tertiary structure probing approach with both targeted and high-throughput readout strategies. Several structural features of late LSU precursors were faithfully detected by this procedure. In addition, the obtained data let us suggest that early rRNA precursor processing events are accompanied by a global transition from a flexible to a spatially restricted rRNA conformation. For intermediate LSU precursors, a number of structural hallmarks could be addressed which include the fold of the internal transcribed spacer between 5.8S rRNA and 25S rRNA, the orientation of the central protuberance and the spatial organization of the interface between LSU rRNA domains I and III.
Project description:The members of plant-specific LSU (RESPONSE TO LOW SULFUR) family were first identified as strongly induced during sulfur starvation. Molecular function of these protein remains unknown, however they were identified as important stress-related hubs by several research groups. In Arabidopsis thaliana there are four members of LSU family. These proteins are involved in multiple protein-protein interactions and literature data suggest that they can integrate abiotic and biotic stress responses. LSU proteins are small and have the coiled-coil structure. Additionally to binding with other proteins they can form homo- and heterodimers and possibly also multimers. In this work we investigated interactions between different monomers of LSU1-4 using Y2H and BiFC methods. The differences in strength of various homo- and heterodimers formation were observed. The constructed by us structural models of the LSU1-4 homo- and heterodimers were in agreement with the experimental observations concerning differences in strength of dimers formation and might help understanding interaction of LSU with other partners. Since previously the partners of LSU were identified using the Y2H approach we decided to obtain the lists of LSU interactors in plants using the TAP-tagged LSU1-4. Interaction of LSUs with a few selected proteins from the lists was verified by Y2H and BiFC.
Project description:The experiment was aimed at identification of genes whose expression is up- or down-regulated in tobacco plants in response to sulfur (S) deficiency. Comparison of response to S deficit of LA Burley 21 line and AB3 line (overexpressing UP9C in antisense orientation) was done to clarify the function of LSU/UP9 family genes.