Analysis of the TORC1 interactome reveals a spatially distinct function of TORC1 in mRNP complexes.

Yeonji Chang, Gyubum Lim, Won-Ki Huh

The Journal of cell biology 2021 Apr 05

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The target of rapamycin complex 1 (TORC1) is mainly localized to the vacuolar membrane and regulates eukaryotic cell growth in response to nutrient availability. To obtain deeper insights into the functional roles of TORC1, we performed a genome-wide analysis of the TORC1 interactome in yeast using the bimolecular fluorescence complementation (BiFC) assay. We found that while most of the BiFC signals are observed at the vacuolar membrane, a fraction of them are detected at cytoplasmic messenger ribonucleoprotein (mRNP) granules. Moreover, mRNA-binding proteins are enriched in the TORC1 interactome, suggesting a functional relationship between TORC1 and mRNA metabolism. We show that a portion of TORC1 is consistently associated with mRNP complexes and interacts with a specific subset of mRNAs. We also demonstrate that TORC1 directly targets a translational repressor Scd6 and that the activity of Scd6 is inhibited by TORC1-dependent phosphorylation. Collectively, our data suggest that TORC1 plays a novel role in posttranscriptional regulation by controlling the activity of Scd6. © 2021 Chang et al.

Citation

Yeonji Chang, Gyubum Lim, Won-Ki Huh. Analysis of the TORC1 interactome reveals a spatially distinct function of TORC1 in mRNP complexes. The Journal of cell biology. 2021 Apr 05;220(4)