PLoS Pathogens | |
Trypanosoma brucei PUF9 Regulates mRNAs for Proteins Involved in Replicative Processes over the Cell Cycle | |
Rafael A. de Queiroz1  Stefanie Brems1  Stuart K. Archer2  Van-Duc Luu2  Christine Clayton2  | |
[1] Deutsches Krebsforschungszentrum, DKFZ-ZMBH Allianz, Heidelberg, Germany;Zentrum für Molekulare Biologie Heidelberg, DKFZ-ZMBH Allianz, Heidelberg, Germany | |
关键词: Kinetoplasts; Cell cycle; cell division; RNA interference; Messenger RNA; Untranslated regions; Northern blot; Trypanosoma; Trypanosoma brucei gambiense; | |
DOI : 10.1371/journal.ppat.1000565 | |
学科分类:生物科学(综合) | |
来源: Public Library of Science | |
【 摘 要 】
Many genes that are required at specific points in the cell cycle exhibit cell cycle–dependent expression. In the early-diverging model eukaryote and important human pathogen Trypanosoma brucei, regulation of gene expression in the cell cycle and other processes is almost entirely post-transcriptional. Here, we show that the T. brucei RNA-binding protein PUF9 stabilizes certain transcripts during S-phase. Target transcripts of PUF9—LIGKA, PNT1 and PNT2—were identified by affinity purification with TAP-tagged PUF9. RNAi against PUF9 caused an accumulation of cells in G2/M phase and unexpectedly destabilized the PUF9 target mRNAs, despite the fact that most known Puf-domain proteins promote degradation of their target mRNAs. The levels of the PUF9-regulated transcripts were cell cycle dependent, peaking in mid- to late- S-phase, and this effect was abolished when PUF9 was targeted by RNAi. The sequence UUGUACC was over-represented in the 3′ UTRs of PUF9 targets; a point mutation in this motif abolished PUF9-dependent stabilization of a reporter transcript carrying the PNT1 3′ UTR. LIGKA is involved in replication of the kinetoplast, and here we show that PNT1 is also kinetoplast-associated and its over-expression causes kinetoplast-related defects, while PNT2 is localized to the nucleus in G1 phase and redistributes to the mitotic spindle during mitosis. PUF9 targets may constitute a post-transcriptional regulon, encoding proteins involved in temporally coordinated replicative processes in early G2 phase.
【 授权许可】
CC BY
【 预 览 】
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