Translational control by the multi-KH domain protein Scp160

摘要: The control of mRNA translation mediated by RNA-binding proteins (RBPs) is a key player in modulating gene expression. In S. cerevisiae, the multi-KH domain protein Scp160 associates with large number mRNAs and present on membrane-bound and, to lesser extent, cytosolic polysomes. Its binding site ribosome close exit tunnel vicinity Asc1, which constitutes platform for signaling molecules. study focused closer characterization Scp160-ribosome interaction suggested function specific target mRNAs. Using affinity purifications, partial RNA-dependence association was confirmed. contrast published results, found be only slightly reduced but not abolished absence Asc1 or last two KH domains. Furthermore, putative elongation regulator Stm1 identified as co-purifier Scp160. subcellular fractionation experiments, mutants were ribosome-free fraction therefore partially deficient and/or mRNP formation. However, no physiological conditions that equally induce shift wildtype towards fraction. Within scope translational profiling approach, microarray analyses RNA isolated from sucrose density gradient fractions performed led identification set their position within gradients upon depletion, indicating changes rates. Consistent membrane localization Scp160, transcripts encoding secreted significantly enriched. Using immunoprecipitation subsequent quantitative real-time PCR (qRT-PCR), subgroup targets confirmed it shown dependent conserved GXXG motifs C-terminal domains data obtained can act activator some its mRNAs, probably level elongation. Finally, first evidence provided misregulation may involved polyploidization hallmark Scp160-deprived cells. In summary, these substantiate assumption regulation specific, functionally related subset This finding good accordance emerging view RBPs co-regulate multiple order allow faster adaptation environmental changes.