1. Functional dissection of the RNA signal sequence responsible for vegetal localization ofXGrip2.1mRNA in Xenopus oocytes
- Author
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Tomas Pieler, Maike Claussen, and Katsiaryna Tarbashevich
- Subjects
Signal peptide ,Xenopus ,ELAV-Like Protein 2 ,Context (language use) ,Mitochondrial cloud ,Protein Sorting Signals ,Xenopus Proteins ,Xenopus laevis ,03 medical and health sciences ,Animals ,RNA, Messenger ,10. No inequality ,3' Untranslated Regions ,Molecular Biology ,030304 developmental biology ,Germ plasm ,0303 health sciences ,Messenger RNA ,biology ,030302 biochemistry & molecular biology ,Intracellular Signaling Peptides and Proteins ,RNA-Binding Proteins ,RNA ,Embryo ,Cell Biology ,biology.organism_classification ,Molecular biology ,Mitochondria ,Ribonucleoproteins ,Mutation ,Oocytes ,Carrier Proteins ,Polypyrimidine Tract-Binding Protein ,Signal Transduction - Abstract
Grip2.1 is a conserved PDZ-domain protein with a function in the context of primordial germ cell development and migration in Xenopus embryos. Its mRNA is maternally supplied and found to be associated with the germ plasm, located at the tip of the vegetal cortex in Xenopus oocytes. Here, we demonstrate that the 3'-UTR of XGrip2.1 contains a 211 nucleotide RNA signal sequence that promotes localization to the mitochondrial cloud via the early localization pathway upon injection into stage I oocytes. The same element is also capable of using the late transport pathway if injected into stage III/IV oocytes. In vitro protein interaction studies reveal binding to ElrA/B, Vg1RBP and VgRBP60, proteins that have previously been associated with the vegetal localization machinery. Mutational interference with Vg1RBP and VgRBP60 binding severely reduces early and late localization activity. Selective interference with Vg1RBP binding significantly reduces late localization while having only a mild effect on localization to the mitochondrial cloud, indicating that the signal sequences and protein machinery required for early and late pathway localization though overlapping are not identical.
- Published
- 2011