New Paper: Trypanosoma brucei histone H1 inhibits RNA polymerase I transcription and is important for parasite fitness in vivo

(This is a guest post by Ana Pena, who is  the first author of Trypanosoma brucei histone H1 inhibits RNA polymerase I transcription and is important for parasite fitness in vivo, a paper I had a small hand in).

 

Pena_Paper_Figure3(Panels A & B from Figure 3 in the paper, showing effects of RNAi knockdown of H1)

The organization of DNA inside the eukaryotic nucleus relies on what we like to call the “beads-on-a-string” structure of chromatin, in which nucleosomes are the “beads” and DNA is the “string” around. While we already know a lot about the histones that make up the nucleosome, the functions of the “extra” histone, histone H1, only now start to be uncovered in vivo.

Histone H1 is a small protein that sits outside the nucleosome “beads” and binds to the DNA between them. In this work we explored the role of histone H1 in Trypanosoma brucei, a unicellular parasite responsible for Sleeping Sickness. Genome-wide RNA expression revealed an interesting fact in this parasite: histone H1 acts mainly as a repressor of a particular cohort of genes, which are transcribed by RNA polymerase I and are essential for its differentiation and survival inside the host. To understand if histone H1 represses transcription at these loci, we performed metabolic labeling of nascent RNAs with 4sU for the first time in this parasite, showing that histone H1 silencing effect is exerted at the transcriptional level.

Full paper citation

Pena AC, Pimentel MR, Manso H, Vaz-Drago R, Neves D, Aresta-Branco F, Ferreira FR, Guegan F, Coelho LP, Carmo-Fonseca M, Barbosa-Morais NL, Figueiredo LM. “Trypanosoma brucei histone H1 inhibits RNA polymerase I transcription and is important for parasite fitness in vivo”. Mol Microbiol, 2014 Jun 19. doi: 10.1111/mmi.12677.

 

Advertisements

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s