title: Nucleolar accumulation of RNA binding proteins induced by Actinomycin D is functional in Trypanosoma cruzi and Leishmania mexicana but not in T. brucei.
abstract: We have recently shown in T. cruzi that a group of RNA Binding Proteins (RBPs), involved in mRNA metabolism, are accumulated into the nucleolus in response to Actinomycin D (ActD) treatment. In this work, we have extended our analysis to other members of the trypanosomatid lineage. In agreement with our previous study, the mechanism seems to be conserved in L. mexicana, since both endogenous RBPs and a transgenic RBP were relocalized to the nucleolus in parasites exposed to ActD. In contrast, in T. brucei, neither endogenous RBPs (TbRRM1 and TbPABP2) nor a transgenic RBP from T. cruzi were accumulated into the nucleolus under such treatment. Interestingly, when a transgenic TbRRM1 was expressed in T. cruzi and the parasites exposed to ActD, TbRRM1 relocated to the nucleolus, suggesting that it contains the necessary sequence elements to be targeted to the nucleolus. Together, both experiments demonstrate that the mechanism behind nucleolar localization of RBPs, which is present in T. cruzi and L. mexicana, is not functional in T. brucei, suggesting that it has been lost or retained differentially during the evolution of the trypanosomatid lineage.
authors: Instituto de Investigaciones Biotecnológicas-Instituto Tecnológico Chascomús, UNSAM-CONICET, San Martín, Provincia de Buenos Aires, Argentina.
authors: Ezequiel
authors: E
authors: Názer
authors: Daniel O
authors: DO
authors: Sánchez
mesh_terms: D002467:Cell Nucleus / Q000378:metabolism*; D003609:Dactinomycin / Q000494:pharmacology*; D007894:Leishmania mexicana / Q000187:drug effects / Q000378:metabolism*; D015800:Protozoan Proteins / Q000378:metabolism*; D016601:RNA-Binding Proteins / Q000378:metabolism*; D014346:Trypanosoma brucei brucei / Q000187:drug effects / Q000378:metabolism*; D014349:Trypanosoma cruzi / Q000187:drug effects / Q000378:metabolism*
chemical_list: D015800:Protozoan Proteins; D016601:RNA-Binding Proteins; D003609:Dactinomycin