title: Functional analysis of Trypanosoma brucei PUF1.
abstract: The genomes of Trypanosoma brucei, Leishmania major and Trypanosoma cruzi each encode 10 proteins with PUF domains. PUF domain proteins from yeast and metazoa have been shown to bind RNA and to regulate mRNA stability and translation. Phylogenetic analysis suggested that the PUF proteins were duplicated and diverged early in evolution, and that most PUF proteins were lost during the evolution of mammals. Depletion of any of the first nine T. brucei PUF protein mRNAs by RNA interference had no effect on cell growth; combined depletion of PUF1 and PUF3, PUF3 and PUF4, and PUF1 and PUF4 mRNAs also had no effect. In conflict with a previous report, procyclic trypanosomes lacking PUF1 genes grew normally and we could find no evidence that PUF1 is required for growth of trypanosomes in culture. Depletion or elimination of PUF1 mRNA did not affect the abundances of any other mRNAs, as detected in microarray analysis, and also had minimal effects on the proteome. (In control experiments, treatment of bloodstream and procyclic cells with 100 ng/ml tetracycline also had no detectable effects on the transcriptome and proteome.) PUF1 preferentially bound to retroposon RNAs and was not associated with polysomes. We suggest that, as in yeast, there may be functional redundancy among the Kinetoplastid PUF proteins, or they may be involved in fine-tuning gene expression together with other proteins. Alternatively, PUF proteins may be needed in differentiating trypanosomes or in non-culturable life-cycle stages.
authors.affiliation: ZMBH, Im Neuenheimer Feld 282, D-69120 Heidelberg, Germany.
authors.forename: Van-Duc
authors.initials: VD
authors.lastname: Luu
authors.forename: Stefanie
authors.initials: S
authors.lastname: Brems
authors.forename: Jörg D
authors.initials: JD
authors.lastname: Hoheisel
authors.forename: Richard
authors.initials: R
authors.lastname: Burchmore
authors.forename: D Lys
authors.initials: DL
authors.lastname: Guilbride
authors.forename: Christine
authors.initials: C
authors.lastname: Clayton
mesh_terms: D000818:Animals; D002352:Carrier Proteins / Q000737:chemistry / Q000235:genetics* / Q000502:physiology*; D047908:Intracellular Signaling Peptides and Proteins; D020411:Oligonucleotide Array Sequence Analysis; D010802:Phylogeny; D011132:Polyribosomes / Q000378:metabolism; D040901:Proteomics; D015800:Protozoan Proteins / Q000737:chemistry / Q000235:genetics* / Q000502:physiology*; D014162:Transfection; D014346:Trypanosoma brucei brucei / Q000235:genetics / Q000254:growth & development / Q000502:physiology*
chemical_list: D002352:Carrier Proteins; D047908:Intracellular Signaling Peptides and Proteins; C456260:PUF21 protein, Trypanosoma brucei; D015800:Protozoan Proteins