ABERRANT TAU-RNA INTERACTIONS DRIVE RIBOSOMAL SELECTIVITY AND CELLULAR DYSFUNCTION
- Jose F. Abisambra, United States of America
Abstract
Aims
A fundamental gap in the field is the incomplete identification of the mechanisms by which tau promotes cellular dysfunction. We and others established that pathological tau shifts the translatome yielding a maladaptive response. However, the molecular mechanisms remain unknown. The overall objective of this study is to establish these mechanisms by defining 1) the impact of pathological tau on translation, 2) the components of RNA translation machinery that interact with tau, 3) alterations to ribosomal transport, and 4) how tau shifts ribosomal specificity promoting a maladaptive translatome.
Methods
We used puromycin to detect changes in newly-synthesized (pumocyinylated) proteins in vitro and in vivo. We then coupled puromycin assays with proteomics or microarrays in the brains of rTg4510 tau transgenic mice to identify proteins altered by tauopathy. We validated results in Alzheimer’s brains using WB, RT-PCR, and E-CLIP. We measured changes in neuronal transport with novel RiboTag-IRES-tau constructs. We also defined the region of tau-ribosome interface region. Finally, we measured changes in translation dynamics with RiboSeq.
Results
We determined that tau expression differentially shifts the transcriptome and the proteome and that the synthesis of ribosomal proteins is reversibly dependent on tau levels. One protein altered by tauopathy is ribosomal protein S6. Ribosomal abnormalities were also identified in Alzheimer’s samples.
Conclusions
Our data establish tau as a driver of RNA translation selectivity. Moreover, considering that regulation of protein synthesis is critical to learning and memory, aberrant tau-RNA/RBPs interactions in disease could explain the linkage between virtually every tauopathy and cognitive impairment and memory decline.