Alternatively spliced isoforms of the human elk-1 mRNA within the 5' UTR: implications for ELK-1 expression.
The expression of cellular proteins that play central roles in the regulation of cell growth and differentiation is frequently tightly controlled at the level of translation initiation. In this article, we provide evidence that the ETS domain transcription factor ELK-1 forms part of this class of genes. Its mRNA 5' UTR is composed of a complexed mosaic of elements, including uAUGs, uORFs and RNA structure, that interplay to modulate ribosomal access to the ELK-1 AUG start codon. Superimposed upon this is the generation of two different 5' UTRs via alternative splicing. The two spliced isoforms show altered cellular and tissue distributions and behave differently in polysomal recruitment assays in the presence of the drug rapamycin. We propose that repression is therefore the sum of a series of interplaying negative elements within the 5' UTRs, a situation which may reflect the need for tight translational control of ELK-1 in different tissues and under changing physiological conditions.
Araud
Tanguy
T
Department of Microbiology and Molecular Medicine, University of Geneva Medical School (CMU), 1 rue Michel Servet, CH-1211 Geneva, Switzerland.
Genolet
Raphael
R
Jaquier-Gubler
Pascale
P
Curran
Joseph
J
D020121:5' Untranslated Regions / Q000737:chemistry*; D017398:Alternative Splicing; D002460:Cell Line; D018387:Codon, Initiator; D006801:Humans; D016366:Open Reading Frames; D010442:Peptide Chain Initiation, Translational; D011401:Promoter Regions, Genetic; D020033:Protein Isoforms / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D050807:ets-Domain Protein Elk-1 / Q000235:genetics* / Q000378:metabolism
D020121:5' Untranslated Regions; D018387:Codon, Initiator; C494112:ELK1 protein, human; D020033:Protein Isoforms; D012333:RNA, Messenger; D050807:ets-Domain Protein Elk-1