Expression of the RNA recognition motif protein RBP10 promotes a bloodstream-form transcript pattern in Trypanosoma brucei.

When Trypanosoma brucei differentiates from the bloodstream form to the procyclic form, there are decreases in the levels of many mRNAs encoding proteins required for the glycolytic pathway, and the mRNA encoding the RNA recognition motif protein RBP10 decreases in parallel. We show that RBP10 is a cytoplasmic protein that is specific to bloodstream-form trypanosomes, where it is essential. Depletion of RBP10 caused decreases in many bloodstream-form-specific mRNAs, with increases in mRNAs associated with the early stages of differentiation.

A domino effect in drug action: from metabolic assault towards parasite differentiation.

Awareness is growing that drug target validation should involve systems analysis of cellular networks. There is less appreciation, though, that the composition of networks may change in response to drugs. If the response is homeostatic (e.

Roles of maltodextrin and glycogen phosphorylases in maltose utilization and glycogen metabolism in Corynebacterium glutamicum.

Corynebacterium glutamicum transiently accumulates large amounts of glycogen, when cultivated on glucose and other sugars as a source of carbon and energy. Apart from the debranching enzyme GlgX, which is required for the formation of maltodextrins from glycogen, alpha-glucan phosphorylases were assumed to be involved in glycogen degradation, forming alpha-glucose 1-phosphate from glycogen and from maltodextrins. We show here that C.

An RNAi screen of the RRM-domain proteins of Trypanosoma brucei.

In eukaryotes, proteins containing RNA Recognition Motifs (RRMs) are involved in many different RNA processing reactions, RNA transport, and mRNA decay. Kinetoplastids rely extensively on post-transcriptional mechanisms to control gene expression, so RRM domain proteins are expected to play a prominent role. We here describe the results of an RNA interference screen targeting 37 of the 72 RRM-domain proteins of Trypanosoma brucei.

Control of mRNA degradation in trypanosomes.

Control of gene expression in trypanosomes relies almost exclusively on post-transcriptional mechanisms. Trypanosomes have the normal enzymes for mRNA decay: both the exosome and a 5'-3'-exoribonuclease are important in the degradation of very unstable transcripts, whereas the CAF1/NOT complex plays a major role in the degradation of all mRNAs tested. Targeted RNA interference screening was used to identify RNA-binding proteins that regulate mRNA degradation, and it revealed roles for proteins with RNA recognition motifs or pumilio domains.