title: Functional dissection of the RNA signal sequence responsible for vegetal localization of XGrip2.1 mRNA in Xenopus oocytes.
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.
authors.affiliation: Department of Developmental Biochemistry, Göttingen Center for Molecular Biosciences, University of Göttingen, Göttingen, Germany.
authors.forename: Maike
authors.initials: M
authors.lastname: Claussen
authors.forename: Katsiaryna
authors.initials: K
authors.lastname: Tarbashevich
authors.forename: Tomas
authors.initials: T
authors.lastname: Pieler
mesh_terms: D020413:3' Untranslated Regions; D000818:Animals; D002352:Carrier Proteins / Q000235:genetics* / Q000378:metabolism; D000067777:ELAV-Like Protein 2; D047908:Intracellular Signaling Peptides and Proteins; D008928:Mitochondria / Q000235:genetics; D009154:Mutation; D009865:Oocytes / Q000378:metabolism*; D038941:Polypyrimidine Tract-Binding Protein / Q000235:genetics / Q000378:metabolism; D021382:Protein Sorting Signals / Q000235:genetics*; D012333:RNA, Messenger / Q000235:genetics; D016601:RNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D012261:Ribonucleoproteins / Q000378:metabolism; D015398:Signal Transduction / Q000235:genetics; D029867:Xenopus Proteins / Q000235:genetics* / Q000378:metabolism; D014982:Xenopus laevis / Q000235:genetics*
chemical_list: D020413:3' Untranslated Regions; D002352:Carrier Proteins; D000067777:ELAV-Like Protein 2; C480172:ELAVL1 protein, Xenopus; C518827:GRIP2 protein, Xenopus; C498635:IGF2BP3 protein, Xenopus; D047908:Intracellular Signaling Peptides and Proteins; D021382:Protein Sorting Signals; D012333:RNA, Messenger; D016601:RNA-Binding Proteins; D012261:Ribonucleoproteins; D029867:Xenopus Proteins; C000593999:elavl2 protein, Xenopus; C450004:hnRNP I-related RNA transport protein VgRBP60, Xenopus; D038941:Polypyrimidine Tract-Binding Protein