Half pint couples transcription and splicing of eIF4E-1,2 gene during fly development.
There are seven genes encoding eight protein isoforms of the translation initiation factor 4E (eIF4E) in Drosophila. One of these genes, eIF4E-1,2, gives rise to three mRNAs with different 5'-untranslated regions (5'UTRs) through alternative splicing regulated by Haf pint (Hfp) in the ovary. eIF4E-1a and eIF4E-1b mRNAs encode the eIF4E-I protein, whereas eIF4E-2 mRNA encodes the eIF4E-II protein. We report here that Hfp regulates alternative splicing of eIF4E-1,2 pre-mRNA during Drosophila development in a sex-independent way. Hfp RNA interference-mediated knockdown in Drosophila S2 cells reproduces the eIF4E-1,2 gene expression found in development. Interestingly, 5'UTRs of eIF4E-1a and -1b isoforms, unlike the eIF4E-2 5'UTR, promote a significant increase in the translation efficiency of a luciferase-encoding chimeric mRNA. Thus, these results suggest that the eIF4E-1,2 gene is regulated by Hfp through a mechanism linked to transcription control and 3' splice site selection, which determines the pattern and translation efficiency of eIF4E-1,2 mRNAs.
Reyes
Raquel
R
Centro de Biología Molecular "Severo Ochoa", UAM-CSIC, C/Nicolás Cabrera 1, Cantoblanco, 28049 Madrid, Spain.
Izquierdo
José M
JM
D017398:Alternative Splicing; D000818:Animals; D029721:Drosophila Proteins / Q000235:genetics* / Q000378:metabolism*; D004331:Drosophila melanogaster / Q000235:genetics / Q000254:growth & development*; D039561:Eukaryotic Initiation Factor-4E / Q000235:genetics*; D005260:Female; D018507:Gene Expression Regulation, Developmental; D020662:Guanine Nucleotide Exchange Factors / Q000235:genetics / Q000378:metabolism*; D008297:Male; D022821:RNA Splice Sites; D020506:Untranslated Regions / Q000378:metabolism
D029721:Drosophila Proteins; D039561:Eukaryotic Initiation Factor-4E; D020662:Guanine Nucleotide Exchange Factors; C484363:Hfp protein, Drosophila; D022821:RNA Splice Sites; D020506:Untranslated Regions; C531248:eIF4E1 protein, Drosophila