The Trypanosoma brucei tRNA methylome

Summary:

A map of the positions of 5-methylcytosines in tRNA was made for Trypanosoma brucei, the causative agent of African Sleeping Sickness.

Abstract:

The Trypanosoma brucei procyclic form and bloodstream form tRNA methylome is reported as revealed by small RNA bisulfite sequencing. 5-methylcytosines were identified at six unique positions with 54 total 5-methylcytosines revealed. The main hot spot for 5-methylcytosine in tRNA is the junction between the variable region and the T-arm.

Primary research questions:

1. What are the positions of 5-methylcytosines in Trypanosoma brucei tRNA? 
2. Do the 5-methylcytosines positions or levels differ throughout the life cycle of the organism? 
3. How do the 5-methylcyotsine positions in Trypanosoma brucei compare to different organisms?

What was known?

At the start of the project, it was known from our past research that T. brucei RNA contains 5-methylcyotsine, but the RNA types, positions, and life cycle regulation was not characterized.

What the research adds to the discussion:

The research indicates that RNAs contain epigenetic modifications (in addition to DNA), and sets up numerous questions on the function of RNA modifications.

Novel methodology:

Sodium bisulfite sequencing of RNA was utilized to find the positions of 5-methylcytosines in RNA.

Implications for society:

It is possible that the enzymes that synthesize 5-methylcytosines represent targets for new drug design to fight infectious disease.

Implications for future research:

We plan to identify the enzymes responsible for 5-methylcytosine in Trypanosoma brucei.

Funding source:

National Institutes of Health grant 1R15AI133428-01