title: Exposure of Bacillus subtilis to mercury induces accumulation of shorter tRNA Cys species.
abstract: RNA processing is an essential pathway in the regulation of genetic expression in the cell. In this work, Bacillus subtilis was used to understand the effects of mercury on the mechanism of tRNA metabolism. The CVAAS (cold vapor atomic absorption spectroscopy) method revealed that from the addition of HgCl2 (0.75 μg ml(-1)) during the bacterial exponential phase, ca. 48% of the added mercury was taken up by the cells. This led to an immediate reduction in the rate of cell division. During this response, we observed accumulation of species shorter than mature tRNA(Cys) over a 10 h period. We did not observe this accumulation for another five tRNAs analyzed. tRNA processing is largely dependent on RNase R and PNPase in B. subtilis. Thus, when the exonuclease PNPase was absent, we found that the shorter tRNA(Cys) species increased and mature tRNA(Cys) decreased after mercury addition, but this proportion changed during the time analyzed. However, in the absence of RNase R and PNPase the accumulation of the shorter tRNA(Cys) was more pronounced and the mature form was not recovered. In the single rnr mutant strain the shorter tRNA(Cys) was not observed. All together, we provide in vivo evidence that PNPase and RNase R are indispensable in controlling tRNA(Cys) quality in the presence of mercury.
authors.forename: Andrés
authors.initials: A
authors.lastname: Cruz Hernández
authors.forename: Emmanuel Sánchez
authors.initials: ES
authors.lastname: Millan
authors.forename: Sergio
authors.initials: S
authors.lastname: de Jesús Romero Gómez
authors.forename: José
authors.initials: J
authors.lastname: Antonio Cervantes Chávez
authors.forename: Rocio
authors.initials: R
authors.lastname: Garcia Martínez
authors.forename: Xóchitl
authors.initials: X
authors.lastname: Pastrana Martínez
authors.forename: Jackeline Lizzeta Arvizu
authors.initials: JL
authors.lastname: Gómez
authors.forename: George H
authors.initials: GH
authors.lastname: Jones
authors.forename: Juan Campos
authors.initials: JC
authors.lastname: Guillén
mesh_terms: D001412:Bacillus subtilis / Q000187:drug effects* / Q000254:growth & development / Q000378:metabolism*; D015152:Blotting, Northern; D008627:Mercuric Chloride / Q000633:toxicity*; D009154:Mutation / Q000235:genetics; D012323:RNA Processing, Post-Transcriptional / Q000187:drug effects; D012329:RNA, Bacterial / Q000235:genetics / Q000378:metabolism*; D012350:RNA, Transfer, Cys / Q000235:genetics / Q000378:metabolism*
chemical_list: D012329:RNA, Bacterial; D012350:RNA, Transfer, Cys; D008627:Mercuric Chloride