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Viral Noncoding RNAs in Modulating Cellular Defense and Their Potential for RNA Nanotechnology
Published in Peixuan Guo, Kirill A. Afonin, RNA Nanotechnology and Therapeutics, 2022
Martin Panigaj, Marina A. Dobrovolskaia, Kirill A. Afonin
The ISGs-encoded RNA-dependent protein kinase R (PKR) and oligoadenylate synthase (OAS) together with RNase L are core enzymes guarding host translation. PKR and OAS are both activated by dsRNA (dsRNA genomes, intermediates in RNA virus genome replication, and secondary structures in ssRNA or bidirectional transcription). Activated PKR phosphorylates the subunit α of eukaryotic initiation factor 2 (eIF2α) leading to inactivation of eIF2 and subsequent overall inhibition of translation initiation. The OAS activity is triggered by dsRNA, too, but in turn it synthesizes second messenger 2′-5′ oligoadenylate (2′-5′ OA) from ATP. Next, 2′-5′ OA binds to an endogenous ribonuclease RNase L, activated monomeric RNase L dimerizes and then cleaves all RNA in the cell leading to apoptosis [49].
Outdoor Air Pollution
Published in William J. Rea, Kalpana D. Patel, Reversibility of Chronic Disease and Hypersensitivity, Volume 4, 2017
William J. Rea, Kalpana D. Patel
In another study carried out on neuroblastoma cells, rotenone-induced ER stress has become evident by increased phosphorylation of protein kinase RNA-like ER kinase (PERK), protein kinase RNA-activated (PKR), and eukaryotic initiation factor 2-a (eIF2a) as well as the expression of GRP78. Moreover, rotenone activates glycogen synthase kinase 3β (GSK3β), an ER-related multifunctional serine/threonine kinase implicated in the pathogenesis of neurodegeneration.179
It's not just about protein turnover: the role of ribosomal biogenesis and satellite cells in the regulation of skeletal muscle hypertrophy
Published in European Journal of Sport Science, 2019
Matthew Stewart Brook, Daniel James Wilkinson, Ken Smith, Philip James Atherton
Protein synthesis is the process by which ribosomes create polypeptide chains through linking amino acids together in a specific order according to mRNA. As such, rates of protein synthesis can be modulated by the rate of mRNA translation, known as “translational efficiency”. A primary control point regulating translational efficiency and therefore protein synthesis in the majority of eukaryotic cells is by cap dependent translation. This involves the assembly of many eukaryotic initiation factors (eIF's) to form a preinitiation complex (PIC) that interacts with the 5′ end of an mRNA to instigate protein synthesis (for more detail readers are directed to [Jackson, Hellen, & Pestova, 2010]). However, with protein synthesis being an energy demanding processes (e.g. through peptide bonding) it is unsurprising that there is myriad of regulating signaling cascades, many of which culminate on the mammalian target of rapamycin (mTOR), that integrates signals such as exercise, AA availability and energy status to coordinate cellular metabolism (Goodman et al., 2011). Some of the best understood targets of mTOR are those directly involved in cap-dependent translation, including P70S6K1, 4E-BP1, and RPS6 that can enhance translation initiation and efficiency in the absence of ribosomal biogenesis (Chesley, MacDougall, Tarnopolsky, Atkinson, & Smith, 1992).