Stress granules in Ciona robusta: First evidences of TIA-1-related nucleolysin and tristetraprolin gene expression under metal exposure

Typical 2-Cys Peroxiredoxins as a Defense Mechanism against Metal-Induced Oxidative Stress in the Solitary Ascidian <em>Ciona robusta</em>

“…An interesting result is that for none of the three isoforms it was possible to identify the sequences of the tunicates as sister groups of the vertebrate sequences, unlike what has been evidenced by recent phylogenetic studies [49]. However, this finding could have been partially expected because analyzes carried out on other gene sequences (γglutamyl-cysteine ligase, glutathione synthetase, superoxide dismutase, glutathione peroxidase, TIA-1 related nucleolysin, tristetraproline) showed phylogenetic relationships similar to those obtained here [35,[37][38][39]. In addition, there is the difficult determination of the phylogeny of tunicates and their peculiar intermediate position between vertebrates and invertebrates to be considered.…”

“…The reduction in the intracellular concentration of Cd may be related to its partial accumulation in the granular amoebocytes of the hemolymph, which then migrate into the tunic, the outer covering of tunicates, which becomes a non-systemic storage site, where these cells undergo cell death by apoptosis [36]. ISH on circulating hemocytes showed that the transcripts for cr-Prdx2, cr-Prdx3, and cr-Prdx4 are mainly located in granular amoebocytes, as demonstrated in previous works [34][35][36][37]39], confirming their role as circulating detoxification system [59]. For cr-Prdx4, granulocytes are not the only immunocytes involved in the detoxification processes from metals.…”

“…Their genetic expression was analyzed at transcriptional and post-transcriptional level in the intestine of C. robusta upon the exposure of animals to copper (Cu), zinc (Zn), and cadmium (Cd) at the same experimental conditions used in previous studies. Finally, we analyzed possible correlation of our results with those previously obtained with other anti-stress proteins, such as metallothioneins [34], the enzymes involved in glutathione (GSH) biosynthesis [35], phytochelatin synthase [36], Cu/Zn superoxide dismutase (Cu/Zn SOD) [37], glutathione peroxidase 7 [38] and proteins for stress granules nucleation [39].…”

“…It is known that there are intracellular compartments, such as P-bodies and stress granules (SGs), in which mRNAs are stored, undergoing degradation or future translation, respectively [63][64][65]. Our previous study demonstrated the importance of SGs in regulating metal-induced stress responses in C. robusta [39]. SG nucleation occurs with the over-expression of mRNA binding proteins, such as TIA-1 related nucleolysin (TIAR) and tristetraprolin (TTP), able to specifically recognize ARE sequences in the promoters for some anti-stress proteins such as Prdxs.…”

“…As carried out in previous studies, ISH was performed on hemolymph extracted from animals exposed for 3 days to metal (FSW in controls) [39]. After pelleting the cells by centrifuging (800 x g for 10 min), hemocytes were resuspended in FSW to a concentration of 10 5 cells/mL and left to adhere on Superfrost Plus glass slides (Menzel-Glaser, Thermo Fisher Scientific, Waltham, MA, USA) for 30 min.…”