Trypanosomes rely on post-transcriptional mechanisms to regulate gene
expression, thus RNA-binding proteins are of particular significance in these
parasites. This project focuses on a CCCH zinc finger protein TbZC3H20, which
is hypothesised to regulate gene expression via mRNA stability, and
consequently control normal cell functions. Using reverse genetics such as RNAi
down-regulation and ectopic over-expression, the role of TbZC3H20 in insect
procyclic form and mammalian bloodstream form Trypanosoma brucei has been
investigated. Phenotypes resulting from perturbing the expression of TbZC3H20
in both life forms were examined and characterised, and these provided clues
about the mRNA species that might be regulated by this protein. In combination
with microarray analysis, specific mRNA targets were selected for further
investigation: to verify that TbZC3H20 regulates transcripts via mRNA stability
and turnover, to demonstrate their direct interaction with TbZC3H20, and to show
that the 3’ UTR is responsible for regulation by TbZC3H20. This analysis also
addressed the possibility of creating TbZC3H20 null mutants in bloodstream
forms and procyclic forms, which indicated the essential nature of TbZC3H20
itself in either life form, as well as providing a useful tool in characterising its role
within the cell. In conclusion, this project reveals a novel RNA-binding protein
that is able to regulate mRNAs involved in the highly coordinated process of
differentiation from one life form to another, as well as regulating life cycle stage
enriched transcripts essential for trypanosome cell survival.