PUBLICATION
Pumilio1 phosphorylation precedes translational activation of its target mRNA in zebrafish oocytes
- Authors
- Saitoh, A., Takada, Y., Horie, M., Kotani, T.
- ID
- ZDB-PUB-181006-7
- Date
- 2018
- Source
- Zygote (Cambridge, England) 26(5): 372-380 (Journal)
- Registered Authors
- Keywords
- Cytoplasmic polyadenylation, Oocyte maturation, RNA granule, Translation, Vertebrate
- MeSH Terms
-
- Actin Cytoskeleton/metabolism
- Animals
- Animals, Genetically Modified
- Cyclin B1/genetics
- Cytoplasmic Granules/genetics
- Cytoplasmic Granules/metabolism
- Female
- Gene Expression Regulation, Developmental
- Green Fluorescent Proteins/genetics
- Green Fluorescent Proteins/metabolism
- Oocytes/physiology*
- Phosphorylation
- Polyadenylation
- Protein Biosynthesis
- RNA, Messenger/genetics*
- RNA, Messenger/metabolism
- RNA-Binding Proteins/genetics
- RNA-Binding Proteins/metabolism*
- Zebrafish/genetics
- Zebrafish Proteins/genetics
- Zebrafish Proteins/metabolism*
- PubMed
- 30289101 Full text @ Zygote
Citation
Saitoh, A., Takada, Y., Horie, M., Kotani, T. (2018) Pumilio1 phosphorylation precedes translational activation of its target mRNA in zebrafish oocytes. Zygote (Cambridge, England). 26(5):372-380.
Abstract
SummaryTranslational regulation of mRNAs is crucial for promoting various cellular and developmental processes. Pumilio1 (Pum1) has been shown to play key roles in translational regulation of target mRNAs in many systems of diverse organisms. In zebrafish immature oocytes, Pum1 was shown to bind to cyclin B1 mRNA and promote the formation of cyclin B1 RNA granules. This Pum1-mediated RNA granule formation seemed critical to determine the timing of translational activation of cyclin B1 mRNA during oocyte maturation, leading to activation of maturation/M-phase-promoting factor (MPF) at the appropriate timing. Despite its fundamental importance, the mechanisms of translational regulation by Pum1 remain elusive. In this study, we examined the phosphorylation of Pum1 as a first step to understand the mechanisms of Pum1-mediated translation. SDS-PAGE analyses and phosphatase treatments showed that Pum1 was phosphorylated at multiple sites during oocyte maturation. This phosphorylation began in an early period after induction of oocyte maturation, which preceded the polyadenylation of cyclin B1 mRNA. Interestingly, depolymerization of actin filaments in immature oocytes caused phosphorylation of Pum1, disassembly of cyclin B1 RNA granules, and polyadenylation of cyclin B1 mRNA but not translational activation of the mRNA. Overexpression of the Pum1 N-terminus prevented the phosphorylation of Pum1, disassembly of cyclin B1 RNA granules, and translational activation of the mRNA even after induction of oocyte maturation. These results suggest that Pum1 phosphorylation in the early period of oocyte maturation is one of the key processes for promoting the disassembly of cyclin B1 RNA granules and translational activation of target mRNA.
Genes / Markers
Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Orthology
Engineered Foreign Genes
Mapping