Article
H2B.V demarcates divergent strand-switch regions, some tDNA loci, and genome compartments in Trypanosoma cruzi and affects parasite differentiation and host cell invasion
Registro en:
ROSÓN, Juliana Nunes et al. H2B.V demarcates divergent strand-switch regions, some tDNA loci, and genome compartments in Trypanosoma cruzi and affects parasite differentiation and host cell invasion. PLoS Pathog, v. 18, n. 2, p. 1–27, 2022.
1553-7374
10.1371/ journal.ppat.1009694
Autor
Rosón, Juliana Nunes
Vitarelli, Marcela de Oliveira
Costa-Silva, Héllida Marina
Pereira, Kamille Schmitt
Pires, David da Silva
Lopes, Leticia de Sousa
Cordeiro, Barbara
Kraus, Amelie J.
Cruz, Karin Navarro Tozzi
Calderano, Simone Guedes
Fragoso, Stenio Perdigão
Siegel, T. Nicolai
Elias, Maria Carolina
Cunha, Julia Pinheiro Chagas da
Resumen
Histone variants play a crucial role in chromatin structure organization and gene expression. Trypanosomatids have an unusual H2B variant (H2B.V) that is known to dimerize with the variant H2A.Z generating unstable nucleosomes. Previously, we found that H2B.V protein is enriched in tissue-derived trypomastigote (TCT) life forms, a nonreplicative stage of Trypanosoma cruzi, suggesting that this variant may contribute to the differences in chromatin structure and global transcription rates observed among parasite life forms. Here, we performed the first genome-wide profiling of histone localization in T. cruzi using epimastigotes and TCT life forms, and we found that H2B.V was preferentially located at the edges of divergent transcriptional strand switch regions, which encompass putative transcriptional start regions; at some tDNA loci; and between the conserved and disrupted genome compartments, mainly at trans-sialidase, mucin and MASP genes. Remarkably, the chromatin of TCT forms was depleted of H2B.V-enriched peaks in comparison to epimastigote forms. Interactome assays indicated that H2B.V associated specifically with H2A.Z, bromodomain factor 2, nucleolar proteins and a histone chaperone, among others. Parasites expressing reduced H2B.V levels were associated with higher rates of parasite differentiation and mammalian cell infectivity. Taken together, H2B.V demarcates critical genomic regions and associates with regulatory chromatin proteins, suggesting a scenario wherein local chromatin structures associated with parasite differentiation and invasion are regulated during the parasite life cycle.