Behind Base J: The Roles of JBP1 and JBP2 on Trypanosomatids

Autor(es)

Assis, Luiz Henrique de Castro ; de Paiva, Stephany Cacete ; Cano, Maria Isabel Nogueira

• Tipo de documento: Artigo Científico
• Fonte: PATHOGENS; v. 12, n. 3, p. 14-pg., 2023-03-01.

Resumo

beta-D-glucopyranosyloxymethiluracil (Base J) is a modified thymidine base found in kinetoplastids and some related organisms. Interestingly, Base J distribution into the genome can vary depending on the organism and its life stage. Base J is reported to be found mostly at telomeric repeats, on inactive variant surface glycoproteins (VSG's) expression sites (e.g., T. brucei), in RNA polymerase II termination sites and sub-telomeric regions (e.g., Leishmania). This hypermodified nucleotide is synthesized in two steps with the participation of two distinct thymidine hydroxylases, J-binding protein 1 and 2 (JBP1 and JBP2, respectively) and a beta-glucosyl transferase. A third J-binding protein, named JBP3, was recently identified as part of a multimeric complex. Although its structural similarities with JBP1, it seems not to be involved in J biosynthesis but to play roles in gene expression regulation in trypanosomatids. Over the years, with the characterization of JBP1 and JBP2 mutant lines, Base J functions have been targeted and shone a light on that matter, showing genus-specific features. This review aims to explore Base J's reported participation as a regulator of RNA polymerase II transcription termination and to summarize the functional and structural characteristics and similarities of the remarkable JBP proteins in pathogenic trypanosomatids. (AU)

• Processo FAPESP: 21/04253-7 - Papel do TERRA na regulação da manutenção dos telômeros e na senescência replicativa em Leishmania major
• Beneficiário: Luiz Henrique de Castro Assis
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 21/14798-0 - Estudos funcionais e estruturais da proteína ortóloga a PinX1 e sua influência nos telômeros de Leishmania spp
• Beneficiário: Stephany Cacete de Paiva
• Modalidade de apoio: Bolsas no Brasil - Doutorado Direto
• Processo FAPESP: 18/04375-2 - Estudos sobre a biogênese e composição do complexo ribonucleoprotéico da telomerase de Leishmania spp. e sua regulação
• Beneficiário: Maria Isabel Nogueira Cano
• Modalidade de apoio: Auxílio à Pesquisa - Temático