The essential function of the Trypanosoma brucei Trl1 homolog in procyclic cells is maturation of the intron-containing tRNATyr.
Trypanosoma brucei, the etiologic agent of sleeping sickness, encodes a single intron-containing tRNA, tRNA(Tyr), and splicing is essential for its viability. In Archaea and Eukarya, tRNA splicing requires a series of enzymatic steps that begin with intron cleavage by a tRNA-splicing endonuclease and culminates with joining the resulting tRNA exons by a splicing tRNA ligase. Here we explored the function of TbTrl1, the T. brucei homolog of the yeast Trl1 tRNA ligase. We used a combination of RNA interference and molecular biology approaches to show that down-regulation of TbTrl1 expression leads to accumulation of intron-containing tRNA(Tyr) and a concomitant growth arrest at the G1 phase. These defects were efficiently rescued by expression of an "intronless" version of tRNA(Tyr) in the same RNAi cell line. Taken together, these experiments highlight the crucial importance of the TbTrl1 for tRNA(Tyr) maturation and viability, while revealing tRNA splicing as its only essential function.
Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Caixa Postal 68041, Brazil Instituto Nacional de Ciência e Tecnologia em Entomologia Molecular (INCT-EM), Caixa Postal 68041, Brazil.
Raphael R S
RR
Lopes
Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Caixa Postal 68041, Brazil Instituto Nacional de Ciência e Tecnologia em Entomologia Molecular (INCT-EM), Caixa Postal 68041, Brazil.
Gilbert de O
Gde O
Silveira
Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Caixa Postal 68041, Brazil.
Roberta
R
Eitler
Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Caixa Postal 68041, Brazil.
Raphael S
RS
Vidal
Department of Microbiology and The Center for RNA Biology, The Ohio State University, Columbus, Ohio 43210, USA.
Alan
A
Kessler
Department of Microbiology and The Center for RNA Biology, The Ohio State University, Columbus, Ohio 43210, USA.
Scott
S
Hinger
Biology Centre, Institute of Parasitology, Czech Academy of Sciences, 37005 České Budějovice (Budweis), Czech Republic.
Zdeněk
Z
Paris
Department of Microbiology and The Center for RNA Biology, The Ohio State University, Columbus, Ohio 43210, USA.
Juan D
JD
Alfonzo
Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Caixa Postal 68041, Brazil Instituto Nacional de Ciência e Tecnologia em Entomologia Molecular (INCT-EM), Caixa Postal 68041, Brazil.
Carla
C
Polycarpo
D000818:Animals; D007438:Introns; D012365:RNA, Transfer, Tyr / Q000378:metabolism*; D014346:Trypanosoma brucei brucei / Q000378:metabolism*
D012365:RNA, Transfer, Tyr
Trypanosoma; intron; splicing; tRNA; tRNA editing