title: Mouse Dazl and its novel splice variant functions in translational repression of target mRNAs in embryonic stem cells.
abstract: Dazl (deleted in azoospermia-like) is an RNA binding protein that is important for germ cell differentiation in vertebrates. In the present study, we report the identification of a novel Dazl isoform (Dazl_Δ8) that results from alternative splicing of exon8 of mouse Dazl. We observed the expression of Dazl_Δ8 in various pluripotent cell types, but not in somatic cells. Furthermore, the Dazl_Δ8 splice variant was expressed along with the full-length isoform of Dazl (Dazl_FL) throughout male germ-cell development and in the ovary. Sub-cellular localization studies of Dazl_Δ8 revealed a diffused cytoplasmic and large granular pattern, which is similar to the localization patterns of Dazl_FL protein. In contrast to the well documented translation stimulation function in germ cells, overexpression and downregulation studies of Dazl isoforms (Dazl_FL and Dazl_Δ8) revealed a role for Dazl in the negative translational regulation of Mvh, a known target of Dazl, as well as Oct3/4 and Sox2 in embryonic stem cells (ESCs). In line with these observations, a luciferase reporter assay with the 3'UTRs of Oct3/4 and Mvh confirmed the translational repressive role of Dazl isoforms in ESCs but not in germ cells derived cell line GC-1. Further, we identified several putative target mRNAs of Dazl_FL and Dazl_Δ8 in ESCs through RNA-binding immunoprecipitation followed by whole genome transcriptome analysis. Collectively, our results show a translation repression function of Dazl in pluripotent stem cells.
authors.affiliation: University of Goettingen, Goettingen, Germany.
authors.forename: Xingbo
authors.initials: X
authors.lastname: Xu
authors.forename: Xiaoying
authors.initials: X
authors.lastname: Tan
authors.forename: Qiong
authors.initials: Q
authors.lastname: Lin
authors.forename: Bernhard
authors.initials: B
authors.lastname: Schmidt
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Engel
authors.forename: D V Krishna
authors.initials: DV
authors.lastname: Pantakani
mesh_terms: D017398:Alternative Splicing; D000818:Animals; D003593:Cytoplasm / Q000378:metabolism; D053487:DEAD-box RNA Helicases / Q000235:genetics / Q000378:metabolism; D015536:Down-Regulation; D053595:Embryonic Stem Cells / Q000378:metabolism*; D005260:Female; D005854:Germ Cells / Q000378:metabolism; D008297:Male; D051379:Mice; D008817:Mice, Mutant Strains; D050814:Octamer Transcription Factor-3 / Q000235:genetics / Q000378:metabolism; D010053:Ovary; D039904:Pluripotent Stem Cells / Q000378:metabolism; D014176:Protein Biosynthesis; D020033:Protein Isoforms / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism*; D016601:RNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D055748:SOXB1 Transcription Factors / Q000235:genetics / Q000378:metabolism
chemical_list: C508515:DAZL protein, mouse; D050814:Octamer Transcription Factor-3; C494174:Pou5f1 protein, mouse; D020033:Protein Isoforms; D012333:RNA, Messenger; D016601:RNA-Binding Proteins; D055748:SOXB1 Transcription Factors; C527783:Sox2 protein, mouse; C090864:Ddx4 protein, mouse; D053487:DEAD-box RNA Helicases