The cytoplasm of Xenopus oocytes contains a factor that protects double-stranded RNA from adenosine-to-inosine modification.
AUTOR(ES)
Saccomanno, L
RESUMO
Here we describe studies of double-stranded RNA (dsRNA) adenosine deaminase in Xenopus laevis, in particular during meiotic maturation, the period during which a stage VI oocyte matures to an egg. We show that dsRNA adenosine deaminase is in the nuclei of stage VI oocytes. Most importantly, we demonstrate that the cytoplasm of stage VI oocytes contains a factor that protects microinjected dsRNA from deamination when dsRNA adenosine deaminase is released from the nucleus during meiotic maturation. Our data suggest that the protection factor is a cytoplasmic dsRNA-binding protein or proteins that bind to dsRNA in a sequence-independent manner to occlude dsRNA from binding to dsRNA adenosine deaminase. The cytoplasmic double-stranded RNA-binding protein(s) does not bind to other nucleic acids and can be titrated at high concentrations of dsRNA. These studies raise the question of whether all dsRNA-binding proteins share endogenous substrates and also suggest potential means of regulating dsRNA adenosine deaminase in vivo.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=359061Documentos Relacionados
- Tat-dependent adenosine-to-inosine modification of wild-type transactivation response RNA.
- Modification of retroviral RNA by double-stranded RNA adenosine deaminase.
- A double-stranded RNA unwinding activity introduces structural alterations by means of adenosine to inosine conversions in mammalian cells and Xenopus eggs.
- Preferential selection of adenosines for modification by double-stranded RNA adenosine deaminase.
- Regulation of a double-stranded RNA modification activity in human cells.