title: P-body components, Dhh1 and Pat1, are involved in tRNA nuclear-cytoplasmic dynamics.
abstract: The nuclear-cytoplasmic distribution of tRNA depends on the balance between tRNA nuclear export/re-export and retrograde tRNA nuclear import in Saccharomyces cerevisiae. The distribution of tRNA is sensitive to nutrient availability as cells deprived of various nutrients exhibit tRNA nuclear accumulation. Starvation induces numerous events that result in translational repression and P-body formation. This study investigated the possible coordination of these responses with tRNA nuclear-cytoplasmic distribution. Dhh1 and Pat1 function in parallel to promote translation repression and P-body formation in response to starvation. Loss of both, Dhh1 and Pat1, results in a failure to repress translation and to induce P-body formation in response to glucose starvation. This study reports that nutrient deprived dhh1 pat1 cells also fail to accumulate tRNA within nuclei. Conversely, inhibition of translation initiation and induction of P-body formation by overproduction of Dhh1 or Pat1 cause tRNA nuclear accumulation in nutrient-replete conditions. Also, loss of the mRNA decapping activator, Lsm1, causes tRNA nuclear accumulation. However, the coordination between P-body formation, translation repression, and tRNA distribution is limited to the early part of the P-body formation/translation repression pathway as loss of mRNA decapping or 5' to 3' degradation does not influence tRNA nuclear-cytoplasmic dynamics. The data provide the first link between P-body formation/translation initiation and tRNA nuclear-cytoplasmic dynamics. The current model is that Dhh1 and Pat1 function in parallel to promote starvation-induced tRNA nuclear accumulation.
authors.affiliation: Department of Molecular Genetics, The Center for RNA Biology, The Ohio State University, Columbus, Ohio 43210, USA.
authors.forename: Rebecca L
authors.initials: RL
authors.lastname: Hurto
authors.forename: Anita K
authors.initials: AK
authors.lastname: Hopper
mesh_terms: D001692:Biological Transport; D002467:Cell Nucleus / Q000378:metabolism*; D003593:Cytoplasm / Q000378:metabolism*; D053487:DEAD-box RNA Helicases / Q000235:genetics / Q000378:metabolism*; D020871:RNA Stability; D012343:RNA, Transfer / Q000378:metabolism*; D016601:RNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000166:cytology / Q000235:genetics / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*
chemical_list: C103266:PAT1 protein, S cerevisiae; D016601:RNA-Binding Proteins; D029701:Saccharomyces cerevisiae Proteins; D012343:RNA, Transfer; C445083:DHH1 protein, S cerevisiae; D053487:DEAD-box RNA Helicases