Abstract
Regulation of RNA polymerase II transcription initiation is apparently absent in trypanosomes. Instead, these eukaryotes control gene expression mainly at the post-transcriptional level. Regulation is exerted through the action of numerous RNA-binding proteins that modulate mRNA processing, turnover, translation and localization. In this work we show that the RNA-binding protein DRBD3 resides in the cytoplasm, but localizes to the nucleus upon oxidative challenge and to stress granules under starvation conditions. DRBD3 associates with other proteins to form a complex, the composition of which is altered by cellular stress. Interestingly, target mRNAs remain bound to DRBD3 under stress conditions. Our results suggest that DRBD3 transports regulated mRNAs within the cell in the form of ribonucleoprotein complexes that are remodeled in response to environmental cues.
Highlights
Kinetoplastids, such as Trypanosoma brucei, Trypanosoma cruzi and Leishmania sp., are protozoa representing one of the deepest branches in the eukaryotic lineage [1]
T. cruzi uridine binding protein 1 (UBP1) is a destabilizing factor that binds to a specific group of mRNAs, and is found in a ribonucleoprotein complex associated with another RNA-binding proteins (RBPs), UBP2 [13,14]
Since transcription initiation is not selectively regulated, it has been proposed that RNA-binding proteins (RBPs)
Summary
Kinetoplastids, such as Trypanosoma brucei, Trypanosoma cruzi and Leishmania sp., are protozoa representing one of the deepest branches in the eukaryotic lineage [1]. Heat shock and starvation promote the accumulation of UBP1, UBP2, the poly(A)-binding proteins PABP1 and PABP2, the RNA-helicase DHH1, the translational repressor SCD6 and several other RBPs in cytoplasmic granules in T. cruzi and T. brucei [17,18].
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have