title: Grsf1-induced translation of the SNARE protein Use1 is required for expansion of the erythroid compartment.
abstract: Induction of cell proliferation requires a concomitant increase in the synthesis of glycosylated lipids and membrane proteins, which is dependent on ER-Golgi protein transport by CopII-coated vesicles. In this process, retrograde transport of ER resident proteins from the Golgi is crucial to maintain ER integrity, and allows for anterograde transport to continue. We previously showed that expression of the CopI specific SNARE protein Use1 (Unusual SNARE in the ER 1) is tightly regulated by eIF4E-dependent translation initiation of Use1 mRNA. Here we investigate the mechanism that controls Use1 mRNA translation. The 5'UTR of mouse Use1 contains a 156 nt alternatively spliced intron. The non-spliced form is the predominantly translated mRNA. The alternatively spliced sequence contains G-repeats that bind the RNA-binding protein G-rich sequence binding factor 1 (Grsf1) in RNA band shift assays. The presence of these G-repeats rendered translation of reporter constructs dependent on the Grsf1 concentration. Down regulation of either Grsf1 or Use1 abrogated expansion of erythroblasts. The 5'UTR of human Use1 lacks the splice donor site, but contains an additional upstream open reading frame in close proximity of the translation start site. Similar to mouse Use1, also the human 5'UTR contains G-repeats in front of the start codon. In conclusion, Grsf1 controls translation of the SNARE protein Use1, possibly by positioning the 40S ribosomal subunit and associated translation factors in front of the translation start site.
authors.affiliation: Dept. Hematology, Erasmus MC, Rotterdam, The Netherlands.
authors.forename: Andrzej
authors.initials: A
authors.lastname: Nieradka
authors.affiliation: Inst. Biochemistry, University Medicine Berlin-Charité, Berlin, Germany.
authors.forename: Christoph
authors.initials: C
authors.lastname: Ufer
authors.affiliation: Dept. Hematopoiesis at Sanquin Research, and Landsteiner Laboratory AMC/UvA, Amsterdam, The Netherlands.
authors.forename: Klaske
authors.initials: K
authors.lastname: Thiadens
authors.affiliation: Dept. Pathology, University of Malta Medical School, Msida, Malta.
authors.forename: Godfrey
authors.initials: G
authors.lastname: Grech
authors.affiliation: Dept. Hematology, Erasmus MC, Rotterdam, The Netherlands.
authors.forename: Rastislav
authors.initials: R
authors.lastname: Horos
authors.affiliation: Dept. Hematology, Erasmus MC, Rotterdam, The Netherlands.
authors.forename: Marleen
authors.initials: M
authors.lastname: van Coevorden-Hameete
authors.affiliation: Dept. Hematopoiesis at Sanquin Research, and Landsteiner Laboratory AMC/UvA, Amsterdam, The Netherlands.
authors.forename: Emile
authors.initials: E
authors.lastname: van den Akker
authors.affiliation: Inst. Biochemistry, University Medicine Berlin-Charité, Berlin, Germany.
authors.forename: Sajad
authors.initials: S
authors.lastname: Sofi
authors.affiliation: Inst. Biochemistry, University Medicine Berlin-Charité, Berlin, Germany.
authors.forename: Hartmut
authors.initials: H
authors.lastname: Kuhn
authors.affiliation: Dept. Hematology, Erasmus MC, Rotterdam, The Netherlands; Dept. Hematopoiesis at Sanquin Research, and Landsteiner Laboratory AMC/UvA, Amsterdam, The Netherlands.
authors.forename: Marieke
authors.initials: M
authors.lastname: von Lindern
mesh_terms: D020413:3' Untranslated Regions; D017398:Alternative Splicing; D000818:Animals; D001483:Base Sequence; D022181:COP-Coated Vesicles / Q000235:genetics / Q000378:metabolism; D049109:Cell Proliferation; D004721:Endoplasmic Reticulum / Q000378:metabolism; D004900:Erythroblasts / Q000166:cytology / Q000378:metabolism*; D039561:Eukaryotic Initiation Factor-4E / Q000235:genetics / Q000378:metabolism; D005786:Gene Expression Regulation; D006056:Golgi Apparatus / Q000378:metabolism; D057809:HEK293 Cells; D006801:Humans; D051379:Mice; D008810:Mice, Inbred C57BL; D008969:Molecular Sequence Data; D041681:NIH 3T3 Cells; D010442:Peptide Chain Initiation, Translational; D039102:Poly(A)-Binding Proteins / Q000235:genetics* / Q000378:metabolism; D011485:Protein Binding; D021381:Protein Transport; D050767:Qc-SNARE Proteins / Q000235:genetics* / Q000378:metabolism; D054682:Ribosome Subunits, Small, Eukaryotic / Q000235:genetics / Q000378:metabolism; D050600:SNARE Proteins; D015398:Signal Transduction; D014452:Ubiquitins / Q000235:genetics* / Q000378:metabolism; D033921:Vesicular Transport Proteins
chemical_list: D020413:3' Untranslated Regions; D039561:Eukaryotic Initiation Factor-4E; C088356:GRSF1 protein, human; D039102:Poly(A)-Binding Proteins; D050767:Qc-SNARE Proteins; D050600:SNARE Proteins; D014452:Ubiquitins; C521756:Use1 protein, human; C539363:Use1 protein, mouse; D033921:Vesicular Transport Proteins