Tollervey lab paper featured in Nature Communications. Authors Image Mistakes are common during the complex processes of gene expression, making quality control and RNA degradation systems essential. This paper helps explain how the TRAMP complexes target specific RNAs to the exosome for destruction. Delan-Forino, C., Spanos, C., Rappsilber, J., and Tollervey, D. Summary of Paper by Lori Koch In the cell, messenger RNAs must be modified and undergo multiple RNA processing steps before reaching a mature form that can be translated into protein. Unfortunately, cells often make mistakes during these processes. Therefore, surveillance mechanisms are essential to prevent defects in gene expression and eliminate aberrant RNAs. Scientists in the Tollervey lab previously identified highly conserved complexes called TRAMP (Trf4/5-Air1/2-Mtr4 polyadenylation) and the exosome, that are crucial for both quality control and RNA processing activities. TRAMP is composed of 3 subunits; an RNA helicase, Mtr4, that unfolds targeted RNA; an RNA binding protein, Air1 or Air2, that was assumed to confer substrate specificity; an oligo(A) polymerase, Trf4 or Trf5, that adds a short, single-stranded “tail” of A residues to RNAs to facilitate degradation. Recent work reported in Nature Communications aimed to determine how TRAMP complexes associate with diverse types of RNAs. In this, they deciphered protein-protein interactions using mass spectrometry, and defined protein-RNA interactions using UV cross-linking and analysis of cDNAs (CRAC). These analyses revealed that three different TRAMP complexes coexist in vivo, each with preferential targets and specific involvement in different RNA processing pathways. Unexpectedly, on many RNAs targeted for degradation, substrate binding specificity is conferred by Trf4 and Trf5, rather than by Air1 and Air2. Additionally, each type of TRAMP complex associated with mRNAs of similar functions, supporting the significance of their surveillance in regulating different aspects of gene expression. Overall, this analysis presents a comprehensive view of how diverse RNAs in the cell are monitored by the TRAMP and exosome complexes. Related links Journal Link Tollervey Lab Website DOI This article was published on 2024-06-17
