Naslov
Mistranslation Upregulates Chaperone Production and Impairs Metabolism and Growth

Autori
Pranjić, Marija ; Močibob, Marko ; Šemanjski, Maja ; Spät, Phillip ; Maček, Boris ; Gruić-Sovulj, Ita

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, ostalo

Izvornik
HDBMB22 From Science to Knowledge / - , 2022, 122-122

Skup
Congress of the Croatian Society of Biochemistry and Molecular Biology: From Science to Knowledge (HDBMB22)

Mjesto i datum
Brela, Hrvatska, 28.09.2022. - 01.10.2022

Vrsta sudjelovanja
Poster

Vrsta recenzije
Nije recenziran

Ključne riječi
Mistranslation ; Isoleucyl-tRNA synthetase ; DnaK

Sažetak
Aminoacyl-tRNA-synthetases (aaRSs) pair tRNAs with their cognate amino acids (aa). To ensure faithful protein biosynthesis, aaRS needs to bind its substrates with high specificity. However, it can be challenging to differentiate cognate aa from other similar competing substrates. For example, cognate isoleucine (Ile) is recognised 160 times better than non-cognate valine (Val) in the active site of isoleucyl-tRNA synthetase (IleRS), which is not enough to ensure minimal translational fidelity. Therefore, IleRS has developed additional editing domain for hydrolysis of mischarged tRNA. To investigate consequences of inactivated IleRS editing, we triggered proteome-wide Ile-to-Val mistranslation and carefully monitored its effect on cellular proteostasis. We constructed the strain MG1655 ileS T243R/D342A (ED-) expressing editing-deficient IleRS and monitored its growth in the presence of 1 mM Val to artificially induce Ile-to-Val mistranslation in Escherichia coli. We investigated in vivo effects of Ile-to-Val mistranslation and by methods of quantitative proteomics compared expression profiles of proteomes isolated from ED- strain in mistranslating and non-mistranslating conditions. We isolated the clients of DnaK, the central chaperone in E. coli, to determine which proteins are structurally most compromised by mistranslation. Ile-to-Val mistranslation impairs bacterial growth rate and within 24 h causes filamentation of cells. Mistranslation upregulates main chaperone systems in E. coli (DnaK/DnaJ/GrpE, GroES/EL and HtpG). On the other hand, it downregulates amino acid biosynthesis. Number of isolated DnaK clients at 37 °C was surprisingly low. We imposed higher temperature (42 °C) to further destabilise already unstable mistranslated proteins and provoke higher number of clients. In this way, isolated DnaK clients in mistranslating conditions were enriched in biological processes most impaired by mistranslation - translation and metabolism. Furthermore, combined effects of heat-shock (42 °C) and mistranslation downregulated other metabolic processes such as carbohydrate metabolism. To conclude with, in mistranslating conditions E. coli upregulates production of chaperones to regulate cellular proteostasis, while lowering down metabolism and growth rate.

Izvorni jezik
Engleski

Znanstvena područja
Kemija, Biologija

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