Pratik Dave, Esther Griesbach, Gregory Roth, Daniel Mateju, Jeffrey A. Chao bioRxiv
(2021)
The relationship between mRNA translation and decay is incompletely understood, with conflicting reports suggesting that translation can either promote decay or stabilize mRNAs. The effect of translation on mRNA decay has mainly been studied using ensemble measurements and global inhibitors of transcription and translation, which can mask the underlying mechanisms. We developed a single-molecule imaging approach to control the translation of a specific transcript that enabled simultaneous measurement of translation and mRNA decay. Our results demonstrate that mRNAs undergoing translation are degraded faster than non-translating ones, although with slower kinetics than translation-coupled degradation of transcripts targeted by NMD. Furthermore, our results indicate that miRNAs mediate efficient degradation of both translating and non-translating target mRNAs. Single-molecule measurements of translation and decay reveal a predominant role of mRNA decay in miRNA-mediated regulation. Simultaneous visualization of translation and decay on single mRNAs provides a framework to study how these processes are interconnected in cells.
Group: Chao, J.
Mateju D, Eichenberger B, Voigt F, Eglinger J, Roth G, Chao JA Cell. 2020 Dec 23;183(7):1801-1812.e13
(2020)
Cellular stress leads to reprogramming of mRNA translation and formation of stress granules (SGs), membraneless organelles consisting of mRNA and RNA-binding proteins. Although the function of SGs remains largely unknown, it is widely assumed they contain exclusively non-translating mRNA. Here, we re-examine this hypothesis using single-molecule imaging of mRNA translation in living cells. Although we observe non-translating mRNAs are preferentially recruited to SGs, we find unequivocal evidence that mRNAs localized to SGs can undergo translation. Our data indicate that SG-associated translation is not rare, and the entire translation cycle (initiation, elongation, and termination) can occur on SG-localized transcripts. Furthermore, translating mRNAs can be observed transitioning between the cytosol and SGs without changing their translational status. Together, these results demonstrate that mRNA localization to SGs is compatible with translation and argue against a direct role for SGs in inhibition of protein synthesis.
Group: Chao, J.
Varun Bhaskar, Min Jia, Jeffrey A. Chao Methods Mol Biol. 2020;2166:269-282
(2020)
Group: Chao, J.
Voigt F, Gerbracht JV, Boehm V, Horvathova I, Eglinger J, Chao JA, Gehring NH Nat Protoc. 2019 May;14(5):1603-1633
(2019)
Group: Chao, J.
Voigt F, Eglinger J, Chao JA Methods Mol Biol. 2018;1649:373-384
(2017)
Group: Chao, J.