Dataset Information

Identification of a conserved RNA motif essential for She2p recognition and mRNA localization to the yeast bud.

ABSTRACT: In Saccharomyces cerevisiae, over twenty mRNAs localize to the bud tip of daughter cells, playing roles in processes as different as mating type switching and plasma membrane targeting. The localization of these transcripts depends on interactions between a cis-acting localization element(s) or zipcodes and the RNA-binding protein She2p. While previous studies identified four different localization elements in the bud-localized ASH1 mRNA, the main determinants for She2p recognition are still unknown. To investigate the RNA-binding specificity of She2p, we isolated She2p-binding RNAs by in vivo selection from libraries of partially randomized ASH1 localization elements. The RNAs isolated contained a similar loop-stem-loop structure with a highly conserved CGA triplet in one loop and a single conserved cytosine in the other loop. Mutating these conserved nucleotides or the stem separating them resulted in the loss of She2p binding and in the delocalization of a reporter mRNA. Using this information, we identified the same RNA motif in two other known bud-localized transcripts, suggesting that this motif is conserved among bud-localized mRNAs. These results show that mRNAs with zipcodes lacking primary sequence similarity can rely on a few conserved nucleotides properly oriented in their three-dimensional structure in order to be recognized by the same localization machinery.

SUBMITTER: Olivier C

PROVIDER: S-EPMC1140632 | biostudies-literature | 2005 Jun

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Identification of a conserved RNA motif essential for She2p recognition and mRNA localization to the yeast bud.

Olivier Catherine C Poirier Guillaume G Gendron Patrick P Boisgontier Anita A Major François F Chartrand Pascal P

Molecular and cellular biology 20050601 11

In Saccharomyces cerevisiae, over twenty mRNAs localize to the bud tip of daughter cells, playing roles in processes as different as mating type switching and plasma membrane targeting. The localization of these transcripts depends on interactions between a cis-acting localization element(s) or zipcodes and the RNA-binding protein She2p. While previous studies identified four different localization elements in the bud-localized ASH1 mRNA, the main determinants for She2p recognition are still unk ...[more]

PMID: 15899876

Similar Datasets

Project description:In eukaryotes, hundreds of mRNAs are localized by specialized transport complexes. For localization, transcripts are recognized by RNA-binding proteins and incorporated into motor-containing messenger ribonucleoprotein particles (mRNPs). To date, the molecular assembly of such mRNPs is not well understood and most details on cargo specificity remain unresolved. We used ASH1-mRNA transport in yeast to provide a first assessment of where and how localizing mRNAs are specifically recognized and incorporated into mRNPs. By using in vitro-interaction and reconstitution assays, we found that none of the implicated mRNA-binding proteins showed highly specific cargo binding. Instead, we identified the cytoplasmic myosin adapter She3p as additional RNA-binding protein. We further found that only the complex of the RNA-binding proteins She2p and She3p achieves synergistic cargo binding, with an at least 60-fold higher affinity for localizing mRNAs when compared to control RNA. Mutational studies identified a C-terminal RNA-binding fragment of She3p to be important for synergistic RNA binding with She2p. The observed cargo specificity of the ternary complex is considerably higher than previously reported for localizing mRNAs. It suggests that RNA binding for mRNP localization generally exhibits higher selectivity than inferred from previous in vitro data. This conclusion is fully consistent with a large body of in vivo evidence from different organisms. Since the ternary yeast complex only assembles in the cytoplasm, specific mRNA recognition might be limited to the very last steps of mRNP assembly. Remarkably, the mRNA itself triggers the assembly of mature, motor-containing complexes. Our reconstitution of a major portion of the mRNA-transport complex offers new and unexpected insights into the molecular assembly of specific, localization-competent mRNPs and provides an important step forward in our mechanistic understanding of mRNA localization in general.

Dataset Information

Identification of a conserved RNA motif essential for She2p recognition and mRNA localization to the yeast bud.

Publications

Identification of a conserved RNA motif essential for She2p recognition and mRNA localization to the yeast bud.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets