Postdoctoral Researcher Umeå Plant science Centre, Umeå University Umea, Vasterbottens Lan, Sweden
Body of Abstract: Plants, as sessile organisms, have developed intricate mechanisms to deal with the changing environment and their state of energy. Target of rapamycin (TOR) complex has a key role in orchestrating the plant cell responses to nutrient availability and external signals. Among other things, TOR primarily regulates ribosome biogenesis and protein synthesis that subsequently reprogram the cell metabolism. These metabolic changes allow the cells to cope with nutritional and external biotic and/or abiotic stresses.
The precise assessment of TOR-mediated translational regulation in plants has remained a challenge due to complexity of plant tissues with different cell types and cell developmental stages as well as lack of a proper technique. In this study, we combined an Arabidopsis cell culture system with ribosome footprinting (Ribo-Seq) to globally investigate the translational control in plant cells and how the TOR-mediated translational regulation results in changes in cell metabolism.
Our results show that TOR inhibition represses gene expression and translation of ribosome biogenesis related proteins that correlates well with the accumulation of amino acids in AZD-8055 treated cells (Dobrenel et al., 2021). We also show that TOR complex might involve 5’ terminal oligopyrimidine (5’ TOP) motifs and upstream open reading frames (uORFs) as two known mechanisms of translational regulation to boost the synthesis of its downstream target proteins. The role TOR plays and the underlaying regulatory mechanisms it uses in translational control will be discussed.
References
Dobrenel T, Kushwah S, Mubeen U, Jansen W, Delhomme N, Caldana C, & Hanson J. 2021. The phosphate starvation response recruits the TOR pathway to regulate growth in Arabidopsis cell cultures. bioRxiv.